Applied Nutrition and Dietetics Full Notes PDF

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Communicative English Applied Biochemistry Pharmacology II Applied Microbiology Applied Anatomy and Infection Control 3rd Semester 4th Semester 2nd Semester Pathology II and 1st Semester Applied Nutrition and Genetics Applied Physiology Pharmacology I Dietetics Adult Health Nursing II Applied Sociology Pathology I Nursing Foundation II Professionalism, Applied Psychology Health/Nursing Adult Health Nursing I Professional Values Informatics & and Ethics Technology Nursing Foundation I Child Health Nursing I Community Health Child Health Nursing Nursing - Internship Mental Health Nursing II Community Health I Nursing II 5th Semester 8th Semester 6th Semester 7th Semester Adult Health Nursing - Mental Health Nursing Internship Community Health II Nursing I Nursing Research & Statistics Child Health Nursing - Nursing Management & Internship Educational Leadership Technology/Nursing Midwifery/Obstetrics Education Mental Health Nursing - Midwifery/Obstetrics and Gynaecology (OBG) Nursing II Internship and Gynaecology (OBG) Introduction to Nursing I Forensic Nursing and Indian laws Midwifery - Internship  All Nursing Subjects- [ BSc., MSc., ] (Click on Subjects to enter) Nutrition & Diet Therapy Psychology Medical Surgical Nursing Psychiatric Mental Health Maternal and Child Health Obstetric and Gynecological Nursing Nursing Nursing Surgical Pathology Anatomy and Physiology 1 Anatomy and Physiology 2 Dissection Sociology of Health Medicine Study Notes Organic Chemistry Introduction to Human Case Study in Obstetrics & Medicine and surgery: Principles Nutrition Gynaecology and practice Obstetrics and Gynecology Modern Pharmacology with Biology laboratory Practicals Clinical Applications Physiology Zoology Medical Microbiology Clinical Cases in Anesthesia Essential Anesthesia From The Massage Connection ANATOMY Science to Practice AND PHYSIOLOGY Microbiology Pathology Microbiology and Immunology Pharmacology Biochemical Pharmacology Biotechnology Radiology Ophthalmology Pharmacology Clinical Dermatology Basic Biochemistry Anesthesiology Biochemistry Orthopaedics Paediatrics Genetics and Molecular Biology of Disease Modern Analytical Chemistry Biology Psychiatry Forensic Medicine Pharmaceutical Drug Analysis Modern Medical Toxicology Human Nervous System and Basic Concept of Biotechnology Sensory Organs Genetics and Molecular Biotechnology Applying the Pharmaceutical Biotechnology: Biology Genetic Revolution Fundamentals and Applications Medical Immunology Essential Microbiology Essential Clinical Immunology Environmental Human Neuroanatomy Diseases of The Brain and Nervous Biotechnology System  www.BrainKart.com www.canestar.com www.nurseinfo.in REVISED SYLLABUS – APPLIED NUTRITION AND DIETETICS NOTES (FIRST YEAR, SECOND SEMESTER) 2021) CONTENTS  INTRODUCTION TO NUTRITION  CARBOHYDRATES AND ENERGY  PROTEINS  FATS  VITAMINS  MINERALS  BALANCED DIET AND NUTRITION ACROSS LIFE CYCLE  NUTRITIONAL DEFICIENCY DISORDERS  THERAPEUTIC DIETS  COOKERY RULES AND PRESERVATION OF NUTRIENTS  NUTRITION ASSESSMENT AND NUTRITION EDUCATION  NATIONAL NUTRITIONAL PROGRAMS AND ROLE OF NURSE  FOOD SAFETY  www.BrainKart.com www.canestar.com www.nurseinfo.in UNIT – 1 INTRODUCTION TO NUTRITION DEFINITION OF NUTRITION AND HEALTH NUTRITION Nutrition is a basic human need and a prerequisite for healthy life. A proper diet is essential from very early age of life for growth, development and active life. Nutrition is the science that deals with all the various factors of which food is composed and the way in which proper nourishment is brought about. This field of study focuses on foods and substances in foods that help animals (and plants) to grow and stay healthy. Nutrition science also includes behaviors and social factors related to food choices. The foods we eat provide energy (calories) and nutrients such as protein, fat, carbohydrate, vitamins, minerals, and water. Eating healthy foods in the right amounts gives your body energy to perform daily activities, helps you to maintain a healthy body weight, and can lower your risk for certain diseases such as diabetes and heart disease. HEALTH Defined health as “a state of complete physical, mental, and social well- being, and not merely the absence of disease or infirmity A triangle is often used to depict the equal influences of physical, mental, and social well-being on health MALNUTRITION – UNDER NUTRITON AND UNDER NUTRITION  www.BrainKart.com www.canestar.com www.nurseinfo.in Malnutrition refers to deficiencies, excesses or imbalances in a person’s intake of energy and/or nutrients. The term malnutrition covers 2 broad groups of conditions. One is ‘undernutrition’—which includes stunting (low height for age), wasting (low weight for height), underweight (low weight for age) and micronutrient deficiencies or insufficiencies (a lack of important vitamins and minerals). The other is overweight, obesity and diet-related noncommunicable diseases (such as heart disease, stroke, diabetes, and cancer). ROLE OF NUTRITION IN MAINTAINING HEALTH Role of nutrition in maintaining health Nutrition is a basic element of health. Nutrition influences the health from birth to death.  www.BrainKart.com www.canestar.com www.nurseinfo.in Growth and development  Good nutrition is essential for attainment of normal growth and development during fetal life and childhood. Physical growth, intellectual development, learning and behavior are affected by malnutrition.  Adequate nutrition is needed for adult life maintenance for optimum health and efficiency.  Elder people need special nutrition due to their physiological and chronological changes. Pregnant and lactating mothers require more proteins and nutrients to prevent abortion, growth retardation and low birth weight babies and provide adequate breast feeding for their babies. Specific deficiency diseases  The most common deficiencies find in Indians are Protein energy malnutrition, blindness, goiter, anemia, beriberi, rickets etc. There is increased incidence of abortion, prematurity, still birth and low birth weight babies in malnourished mothers.  Hence, good nutrition is essential to prevent nutritional deficiency diseases, promotion of health and treatment of deficiency diseases. Resistance to infection  A well balanced nutrition prevents infections like tuberculosis. Good nutrition enhances wound healing. Improves resistance of an individual towards infections. Mortality and morbidity  www.BrainKart.com www.canestar.com www.nurseinfo.in  Malnutrition leads to increased death rate, infant mortality rate, still births and premature deliveries. Prematurity is the major cause of deaths.  Over nutrition causes diseases like Obesity, diabetes, hypertension, cardiovascular and renal diseases and causes death FACTORS AFFECTING FOOD AND NUTRITION Factors affecting food and nutrition The following factors affect food and nutrition  Basal metabolic rate  Weight  Age  Sex  Climate and environment  Physical activities  Physiological state  Socio economic factors  Cultural factors  Life style and food habits  Food fads  Cooking practices  Child rearing practices  Religion  Traditional factors  www.BrainKart.com www.canestar.com www.nurseinfo.in  Food production and distribution Food Pyramid According to Indian Council of Medical Research, foods are grouped as shown in Pyramid according to the requirement for healthy life. Each food groups is a source of different nutrients. Balanced diet should include all the food groups. NUTRIENTS - CLASSIFICATION Nutrients are chemical substances found in food that are required by the body to provide energy, give the body structure, and help regulate chemical processes. There are six classes of nutrients: 1. Carbohydrates  www.BrainKart.com www.canestar.com www.nurseinfo.in 2. Lipids 3. Proteins 4. Water 5. Vitamins 6. Minerals Nutrients can be further classified as either macronutrients or micronutrients and either organic or inorganic, as well as whether or not they provide energy to the body (energy-yielding). MACRONUTRIENTS Nutrients that are needed in large amounts are called macronutrients. There are three classes of macronutrients: carbohydrates, lipids, and proteins. Water is also a macronutrient in the sense that you require a large amount of it, but unlike the other macronutrients, it does not yield energy. Carbohydrate Carbohydrates are molecules composed of carbon, hydrogen, and oxygen. The major food sources of carbohydrates are grains, dairy products, fruits, legumes, and starchy vegetables, like potatoes. Non- starchy vegetables, like carrots, also contain carbohydrates, but in lesser quantities. Carbohydrates are broadly classified into two groups based on their chemical structure: simple carbohydrates (often called simple sugars) and complex carbohydrates, which include fiber, starch, and glycogen.  www.BrainKart.com www.canestar.com www.nurseinfo.in Carbohydrates are a major fuel source for all cells of the body, and certain cells, like cells of the central nervous system and red blood cells, rely solely on carbohydrates for energy. Lipids Lipids are also a family of molecules composed of carbon, hydrogen, and oxygen, but unlike carbohydrates, they are insoluble in water. Lipids are found predominantly in butter, oils, meats, dairy products, nuts and seeds, and in many processed foods. The three main types of lipids are triglycerides, phospholipids, and sterols. The main job of lipids is to provide or store energy. In addition to energy storage, lipids serve as major components of cell membranes, surround and protect organs, provide insulation to aid in temperature regulation, and regulate many other functions in the body. Proteins Proteins are large molecules composed of chains of amino acids, which are simple subunits made of carbon, oxygen, hydrogen, and nitrogen. Food sources of proteins include meats, dairy products, seafood, and a variety of plant-based foods, like beans, nuts, and seeds. The word protein comes from a Greek word meaning “of primary importance,” which is an apt description of these macronutrients as they are also known as the “workhorses” of life. Proteins provide structure to bones, muscles, and skin, and they play a role in conducting most of the chemical reactions occurring in the body. Proteins can also provide energy, though this is a relatively minor function, as carbohydrates and fat are preferred energy sources. Water  www.BrainKart.com www.canestar.com www.nurseinfo.in There is one other nutrient that we must have in large quantities: water. Water does not contain carbon but is composed of two hydrogens and one oxygen per molecule of water. More than 60 percent of your total body weight is water. Without it, nothing could be transported in or out of the body, chemical reactions would not occur, organs would not be cushioned, and body temperature would fluctuate widely. On average, an adult consumes just over two liters of water per day from food and drink combined. Since water is so critical for life’s basic processes, we can only survive a few days without it, making it one of the most vital nutrients. MICRONUTRIENTS Micronutrients are nutrients required by the body in smaller amounts, but they’re still essential for carrying out bodily functions. Micronutrients include all of the essential minerals and vitamins. There are 16 essential minerals and 13 essential vitamins. In contrast to carbohydrates, lipids, and proteins, micronutrients are not a source of energy, but they assist in the process of energy metabolism as cofactors or components of enzymes (known as coenzymes). Enzymes are proteins that catalyze (or accelerate) chemical reactions in the body; they’re involved in all aspects of body functions, including producing energy, digesting nutrients, and building macromolecules. Minerals Minerals are inorganic substances that are classified depending on how much the body requires. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine, are only required in amounts of a few milligrams or less per day. Major minerals, such as calcium, magnesium, potassium, sodium, and phosphorus, are required in amounts of  www.BrainKart.com www.canestar.com www.nurseinfo.in hundreds of milligrams or more per day. Many minerals are critical for enzyme function, and others are used to maintain fluid balance, build bone tissue, synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against harmful free radicals in the body. Major Minerals Major Function Sodium Fluid balance, nerve transmission, muscle contraction Chloride Fluid balance, stomach acid production Potassium Fluid balance, nerve transmission, muscle contraction Calcium Bone and teeth health maintenance, nerve transmission, muscle contraction, blood clotting Phosphorus Bone and teeth health maintenance, acid-base balance Magnesium Protein production, nerve transmission, muscle contraction Sulfur Protein production Trace Minerals Function Iron Carries oxygen, assists in energy production Zinc Protein and DNA production, wound healing, growth, immune system function Iodine Thyroid hormone production, growth, metabolism Selenium Antioxidant Copper Coenzyme, iron metabolism Manganese Coenzyme Fluoride Bone and teeth health maintenance, tooth decay prevention Chromium Assists insulin in glucose metabolism Molybdenum Coenzyme Vitamins Vitamins are organic nutrients that are categorized based on their solubility in water. The water-soluble vitamins are vitamin C and all of  www.BrainKart.com www.canestar.com www.nurseinfo.in the B vitamins. The fat-soluble vitamins are vitamins A, D, E, and K. Vitamins are required to perform many functions in the body, such as making red blood cells, synthesizing bone tissue, and playing a role in normal vision, nervous system function, and immune function. To give you an appreciation of the many functions of vitamins, the table below lists the 13 essential vitamins and their major functions. Water-Soluble Vitamins Major Functions Thiamin (B1) Coenzyme, energy metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5) Coenzyme, energy metabolism assistance Pyridoxine (B6) Coenzyme, energy metabolism assistance Biotin (B7) Coenzyme, amino acid and fatty acid metabolism Folate (B9) Coenzyme, essential for growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic acid) Collagen synthesis, antioxidant Fat-Soluble Vitamins Major Functions A Vision, reproduction, immune system function D Bone and teeth health maintenance, immune system function E Antioxidant, cell membrane protection K Bone and teeth health maintenance, blood clotting ENERGY YIELDING NUTRIENTS The macronutrients—carbohydrate, protein, and fat—are the only nutrients that provide energy to the body. The energy from macronutrients comes from their chemical bonds. This chemical energy  www.BrainKart.com www.canestar.com www.nurseinfo.in is converted into cellular energy that can be utilized to perform work, allowing cells to conduct their basic functions. Although vitamins also have energy in their chemical bonds, our bodies do not make the enzymes to break these bonds and release this energy. (This is fortunate, as we need vitamins for their specific functions, and breaking them down to use for energy would be a waste.) Food energy is measured in kilocalories (kcals). A kilocalorie is the amount of energy needed to raise 1 kilogram of water by 1 degree Celsius. The kilocalories stored in food can be determined by putting the food into a bomb calorimeter and measuring the energy output (energy = heat produced). In the US, the kilocalorie (kcal) is the most commonly used unit of energy and is often just referred to as a calorie. Strictly speaking, a kcal is 1000 calories. In nutrition, the term calories almost always refer to kcals. Sometimes the kcal is indicated by capitalizing calories as “Calories.” For the sake of simplicity, we’ll use the terms “calories” and “kilocalories” interchangeably in this book. Below is a list of energy sources in the diet from lowest to highest calories per gram (a gram is about the weight of a paperclip). Notice the addition of alcohol. Although alcohol does provide energy, it isn’t a nutrient, because it isn’t required as a source of nourishment to the body. Energy Sources (kcal/g)  Carbohydrates 4  Protein 4  Alcohol 7  www.BrainKart.com www.canestar.com www.nurseinfo.in  Lipids 9 Carbohydrates and proteins provide 4 calories per gram, and fats provide 9 calories per gram. Fat is the most energy-dense nutrient, because it provides the most calories per gram (more than double carbohydrates and protein). ORGANIC AND INORGANIC NUTRIENTS So far, we’ve categorized nutrients as macronutrients or micronutrients and based on whether or not they’re energy-yielding. There is one more way to categorize nutrients: organic or inorganic. When you think of the word “organic,” you might think of how foods are produced (with or without synthetic fertilizers and pesticides), but in this case we are referring to the chemical structure of a nutrient. Organic Nutrients The organic nutrients include the macronutrients (carbohydrate, protein, and fat) and vitamins. An organic nutrient contains both carbon and hydrogen. Organic nutrients can be made by living organisms and are complex, made up of many elements (carbon, hydrogen, oxygen, and sometimes nitrogen) bonded together. In a sense, they are “alive,” and therefore can be destroyed or broken down. Vitamin E is an organic molecule, because it contains both carbon and hydrogen atoms. Vitamin E is synthesized by plants and can be destroyed by heat during cooking. Inorganic Nutrients  www.BrainKart.com www.canestar.com www.nurseinfo.in Inorganic nutrients include both water and minerals. Inorganic nutrients do not contain both carbon and hydrogen, and they are not created or destroyed. Minerals can’t be destroyed, so they are the ash left when a food is burned to completion. Minerals are also not digested or broken down, as they are already in their simplest form. They are absorbed as-is, then shuttled around the body for their different functions, and then excreted. Classification Nutrient Macronutrient Carbohydrate, protein, lipids, water Micronutrient Vitamins, minerals Energy-Yielding Carbohydrate, protein, fat Organic Carbohydrate, protein, lipids, vitamins Inorganic Minerals, water FOOD CLASSIFICATION – FOOD GROUPS Food can be classified in accordance to their chemical property, to their function, to their essentiality, to their concentration and to their nutritive value. CLASSIFICATION OF FOOD Food can be classified in accordance to their chemical property, to their function, to their essentiality, to their concentration and to their nutritive value.  www.BrainKart.com www.canestar.com www.nurseinfo.in a) According to the chemical nature Carbohydrates Vitamins Proteins Dietary fiber Fats Water minerals b) According to their function in the body  www.BrainKart.com www.canestar.com www.nurseinfo.in Energy giving foods The carbohydrates, fats and the protein are considered as calorie nutrients, so that the body can perform the necessary functions. Rice, chapatti, bread, potato, sugar, oil, butter and ghee are examples of energy giving foods. Body building foods Foods such as proteins, fats and carbohydrates are also called as body- building food. They are the nutrients that form body tissues. Fish, meat, chicken, eggs, pulses, nuts and milk are some body building foods. Protective foods Vitamins and minerals are the nutrients that function to regulate body processes. They protect us from various diseases. Fruits and vegetables are some examples. Therefore we must eat these regularly.  www.BrainKart.com www.canestar.com www.nurseinfo.in c) According to chemical properties Organic: Nutrients that contain the element of carbon are called as organic nutrients. Inorganic: Nutrients that do not contain carbon element are called as inorganic nutrients. The organic nutrients include carbohydrates, lipids, proteins and vitamins. Water and minerals are inorganic. d) According to its mass depending on the quantity necessary for cells and organisms are classified as Macronutrients: Macronutrients are required in large quantities daily. Proteins, carbohydrates and fats are macronutrients. They are the basis of any diet. Micronutrients: Micronutrients are needed in small quantities (usually in amounts less than milligrams). These nutrients are involved in regulating metabolism and energy processes. They are vitamins and minerals. e) According to its origin Depending upon the origin of food it has been classified as animal food sources and plant food sources.  www.BrainKart.com www.canestar.com www.nurseinfo.in f) According to its nutritive value Cereals and millets Pulses Nuts and oil seeds Vegetables Green leafy vegetables Non-leafy vegetables Roots and tubers Fruits Milk and milk products Animal foods—meat, fish, liver, egg etc Carbohydrate foods Condiments and spices  www.BrainKart.com www.canestar.com www.nurseinfo.in UNIT – 2 CARBOHYDRATES COMPOSITION – STARCHES, SUGAR AND CELLULOSE Carbohydrates are "polyhydroxy aldehydes, ketones, alcohols, acids, their simple derivatives and their polymers having polymeric linkages of the acetal type". Carbohydrates are further classified according to their degree of polymerization (DP) as: sugars (mono- and disaccharides), oligosaccharides (contain three to nine monosaccharide units), and polysaccharides (contain ten or more monosaccharide units). Carbohydrates play a major role in human diets, comprising some 40- 75% of energy intake. Their most important nutritional property is digestibility in the small intestine. In terms of their physiological or nutritional role, they are often classified as available and unavailable carbohydrates. Available carbohydrates are those that are hydrolyzed by enzymes of the human gastrointestinal system to monosaccharides that are absorbed in the small intestine and enter the pathways of carbohydrate metabolism. Unavailable carbohydrates are not hydrolyzed by endogenous human enzymes, although they may be fermented in the large intestine to varying extents. Small amounts of other carbohydrates can be detected in some foods but these are of little overall significance. These include maltose, commonly formed from hydrolysis of starch and found in starch hydrolyzates used as food ingredients; galactose from fermented dairy products; and pentoses, such as xylose and arabinose, from fruits. The most important carbohydrates in foods Monosaccharides Glucose, Fructose  www.BrainKart.com www.canestar.com www.nurseinfo.in Disaccharides Sucrose, Lactose Oligosaccharides Raffinose, Stachyose, Fructo-oligosaccharides Polysaccharides Cellulose, Hemicelluloses, Pectins, b -Glucans, Fructans, Gums, Mucilages, Algal polysaccharides Sugar alcohols Sorbitol, Mannitol, Xylitol, Lactitol, Maltitol Monosaccharides Glucose (also called dextrose) is found in varying amounts in honey, maple syrup, fruits, berries, and vegetables. Glucose is often formed from the hydrolysis of sucrose, as in honey, maple sugar, and invert sugar. It is also present in foods containing starch hydrolysis products, such as corn syrups and high-fructose corn syrups. The amount of glucose contained in these starch hydrolysates depends on the method used in their preparation, e.g. acid conversion, acid-enzyme conversion, or enzyme conversion. Small amounts of glucose are also found in maltodextrins and corn syrup solids, commonly used as ingredients in food products. The physicochemical properties of glucose that are important in its use as a food ingredient include flavour, sweetness, hygroscopicity, and humectancy. It is about 70-80% as sweet as sucrose. Since glucose is a reducing sugar, i.e. contains a carbonyl function at the C-1 position, it readily undergoes the Maillard or browning reaction with amino acids. This behaviour is responsible for the golden-brown colour of bread crusts and for the caramel colour and flavour observed in certain other  www.BrainKart.com www.canestar.com www.nurseinfo.in foods. If the reaction is sufficiently extensive, dark brown colours and altered flavours can result in food products. Fructose is present in honey, maple sugar, fruits, berries and vegetables. Fructose is often present from the hydrolysis of sucrose, as in honey, maple sugar, and invert sugar. It may also be present in food products, such as soft drinks, bakery products, and candies from the use of invert sugar, crystalline fructose or high-fructose corn syrups (HFCS). HFCS are often used as a sweetening agent, particularly in carbonated soft drinks. Fructose is 140% sweeter than sucrose. As a keto-hexose, fructose is very reactive with amino acids in the Maillard or browning reaction. Disaccharides Sucrose (a -D-glucopyranosyl b -D-fructofuranoside or b -D- fructofuranosyl a -D-glucopyranoside) is a nonreducing sugar and is the major disaccharide in most diets. It is present in honey, maple sugar, fruits, berries, and vegetables. It may be added to food products as liquid or crystalline sucrose or as invert sugar (if not completely inverted to fructose and glucose). It is commercially prepared from sugar cane or sugar beets. Sucrose can provide a number of desirable functional qualities to food products including sweetness, mouth-feel, and the ability to transform between amorphous and crystalline states. Sucrose often cannot be easily replaced by other sweeteners due to its lack of aftertaste, browning, and gummy mouth-feel and its characteristic body, viscosity and sweetness profile. This is particularly true in baked products where equivalent replacement, particularly with high intensity sweeteners, often results in a product with decreased textural characteristics and consumer acceptance. Sucrose and invert  www.BrainKart.com www.canestar.com www.nurseinfo.in sugar are used in many food products including ice cream, baked goods, desserts, confections, intermediate-moisture foods, and soft drinks. Its use in soft drinks has decreased because of the increased usage of high-fructose corn syrups due to availability and lower costs. Lactose (4-O-b -D-galactopyranosyl-D-glucose), a reducing sugar also known as milk sugar, occurs in milk and milk products. It may also occur in food products that contain dairy products as ingredients, such as doughnuts, wafer cookie bars, breakfast bars, and hamburger buns. Whey is used as an ingredient in foods and is high in lactose content. Lactose crystallizes easily and is often responsible for the grittiness encountered in ice cream when crystallization is not inhibited. Lactose serves as an energy source for infants during the nursing period. Lactose is hydrolyzed in the small intestine by the enzyme lactase to galactose and glucose which are then absorbed. Oligosaccharides Oligosaccharides are not widely occurring or of great importance in foods and food products, except for a series of galactosylsucroses (often designated as a -galactosides) and fructo-oligosaccharides. The galactosylsucrose family of oligosaccharides include raffinose (a trisaccharide), stachyose (a tetrasaccharide), and verbascose (a pentasaccharide). In vegetables, such as peas, beans, and lentils, the content of these oligosaccharides can range from five to eight percent on a dry matter basis. Raffinose, stachyose, and verbascose are not digested in the small intestine by human gastrointestinal enzymes. They are passed into the large intestine where they are fermented by intestinal microflora with the production of gas. It is this behaviour that produces the flatulence for which the consumption of beans is noted.  www.BrainKart.com www.canestar.com www.nurseinfo.in Enzyme preparations are commercially available which can be taken with meals to reduce the tendency for flatulence production by promoting the hydrolysis of these oligosaccharides to constituent monomers which are absorbed. Fructo-oligosaccharides occur in wheat, rye, triticale, asparagus, onion, and Jerusalem artichoke and a number of other plants. Fructo- oligosaccharides and higher molecular weight fructans can comprise 60-70% of the dry matter in Jerusalem artichokes. Fructo- oligosaccharides have been commercially prepared by the action of a fructofuranosyl furanosidase from Aspergillus niger on sucrose. They are about 30% as sweet as sucrose, have a taste profile similar to sucrose, are stable at pH values above 3 and at temperatures up to 140°C. Since fructo-oligosaccharides are non-reducing oligosaccharides, they do not undergo the Maillard browning reaction. Polysaccharides Starch Starch is the most important, abundant, digestible food polysaccharide. It occurs as the reserve polysaccharide in the leaf, stem (pith), root (tuber), seed, fruit and pollen of many higher plants. It occurs as discrete, partially-crystalline granules whose size, shape, and gelatinization temperature depend on the botanical source of the starch. Common food starches are derived from seed (wheat, maize, rice, barley) and root (potato, cassava/tapioca) sources (see Table 6). Starches have been modified to improve desired functional characteristics and are added in relatively small amounts to foods as food additives.  www.BrainKart.com www.canestar.com www.nurseinfo.in Starch is a homopolysaccharide composed only of glucose units and consists of a mixture of two polymers, amylose and amylopectin, whose glucopyranosyl units are linked almost entirely through a -D-(1->4)- glucosidic bonds. Amylose shows many of the properties of a linear polymer and has historically been considered to be a linear polymer with a degree of polymerization of approximately 1000 or less. However, it is now known that amylose contains a limited amount of branching involving a -D-(l->6)-glucosidic linkages at the branch points. Amylopectin is a high molecular weight, highly branched polymer containing about 5-6% of a -D-(1->6)-glucosidic linkages as the branch points. The average chain length is 20 to 25 units with an average degree of polymerization in the thousands, and molecular weight in the millions. While the manner in which amylose and amylopectin are organized to form the starch granule is not clearly understood, the granule is partially crystalline exhibiting an x-ray diffraction pattern and birefringence. Most common cereal starches contain 20-30% amylose. Waxy starches (maize, rice, sorghum, barley) have no amylose and contain essentially 100% amylopectin. The first example of a waxy wheat starch has recently been reported from Japan. High-amylose starches (maize, barley) having 50-70% amylose are available. Waxy and high-amylose starches differ from normal starches in some properties that make them of use in certain food products. A number of double and triple maize starch mutants are being investigated to determine whether they have unique or desirable physicochemical and/or functional properties that would make them of use in selected food products. Modified starches  www.BrainKart.com www.canestar.com www.nurseinfo.in Many starches do not have the functional properties needed to impart or maintain desired qualities in food products. As a result, some starches have been modified to obtain the functional properties required. The starches most commonly modified for commercial use are those from normal maize, tapioca, potato, and waxy maize. Modified starches are used to improve viscosity, shelf stability, particulate integrity, processing parameters, textures, appearance and emulsification. While virtually all of the different types of modified starches find use in the food industry, substituted and cross-linked starches are particularly important. These two types of modified starches are produced by reactions in which a small number of hydroxyl groups on the glucose units of amylose and amylopectin, mostly in amorphous regions and on the surface of the granule, are modified without destroying the granular nature of the starch. Substituted starches are produced by etherification or esterification. This reduces the tendency of chains to realign (retrograde) following gelatinization of starch during heat processing. Substitution lowers the gelatinization temperature, gives freeze-thaw stability, increases viscosity, increases clarity, inhibits gel formation, and reduces syneresis. Cross-linked starches are produced by introducing a limited number of linkages between the chains of amylose and amylopectin using difunctional reagents. Cross-linking essentially reinforces the hydrogen bonding occurring within the granule. It increases gelatinization temperature; improves acid stability, heat stability and shear stability; inhibits gel formation; and controls viscosity during processing. Dietary fibre  www.BrainKart.com www.canestar.com www.nurseinfo.in Dietary fibre has been considered to be composed of non-starch polysaccharides plus lignin plus resistant oligosaccharides plus resistant starch. Since lignin is not a carbohydrate, it will not be discussed. Dietary fibre occurring in foods and food products can be considered to consist of cellulose, hemicelluloses, pectic substances, hydrocolloids (gums and mucilages), resistant starches, and resistant oligosaccharides. Cellulose, the major cell wall structural component in plants, is an unbranched linear chain of several thousand glucose units with b -D-(1- >4)-glucosidic linkages. Cellulose's mechanical strength, resistance to biological degradation, low aqueous solubility, and resistance to acid hydrolysis result from hydrogen bonding within the microfibrils. There is a portion (10-15%) of the total cellulose, referred to as "amorphous," that is more readily acid hydrolyzed. Controlled acid hydrolysis of the amorphous fraction yields microcrystalline cellulose. Cellulose has been used as a bulking agent in food due to its water-absorbing ability and low solubility. Some of the early dietary fibre ingredient sources were based on cellulose powders or microcrystalline cellulose. Cellulose is not digested to any extent by the enzymes of the human gastrointestinal system. Hemicelluloses may be present in soluble and insoluble forms and are comprised of a number of branched and linear pentose- and hexose- containing polysaccharides. In cereal grains, soluble hemicelluloses are termed "pentosans." Hemicelluloses are of much lower molecular weight than cellulose. Component monosaccharide units may include xylose, arabinose, galactose, mannose, glucose, glucuronic acid, and galacturonic acid.  www.BrainKart.com www.canestar.com www.nurseinfo.in Mixed linkage b -glucans, the (1->3) (1->4)- b -D-glucans, have generated considerable interest in recent years due to their physiological response as soluble dietary fibre. While these glucans are found in relatively small quantities in wheat, they are a major component of cell-call material in barley and oats. These glucans form viscous aqueous solutions and have been shown to be effective in reducing serum cholesterol concentrations. Oat bran, a rich source of b -D-glucan, has been incorporated into many food products, particularly cereals, as a source of the soluble fibre that has been touted for cholesterol reduction. Both soluble and insoluble hemicelluloses play important roles in food products, the former functioning as soluble and the latter as insoluble fibre. They are characterized by their ability to bind water and hence serve as bulking agents. The presence of acidic components in some hemicelluloses impart the capacity to bind cations. Hemicelluloses are fermented to a greater extent than cellulose in the colon. Pectins find widespread use in foods such as jams and jellies because of their ability to form stable gels. Completely esterified pectins do not require the addition of acid or electrolyte to form gels. The presence of calcium salts enhances the gelling capacity and decreases the dependence on pH and sugar concentration. Pectic substances are of importance as a component of dietary fibre because of their ion- exchange properties, due to the presence of the galacturonic acid units, and gelling (viscosity enhancing) properties. Hydrocolloids (gums, mucilages) are used in small amounts in food products for their thickening (viscosity increasing), gelling, stabilizing, or  www.BrainKart.com www.canestar.com www.nurseinfo.in emulsifying ability. They are derived from seaweed extracts, plant exudes, seeds, and microbial sources. Resistant starch While starch was long thought to be completely digested, it is now recognized that there is a portion (resistant starch) which resists digestion, passes into the lower intestine, and is fermented there. Resistant starch has been defined as "the sum of starch and products of starch degradation not absorbed in the small intestine of healthy individuals". Three types of resistant starch have been identified: 1. RS1 - Physically trapped starch: These starch granules are physically trapped within a food matrix so that digestive enzymes are prevented or delayed from having access to them. This can occur in whole or partly ground grains, seeds, cereals, and legumes. The amount of type 1 resistant starch will be affected by food processing and can be decreased or eliminated by milling. 2. RS2 - Resistant starch granules: Certain raw (native) starch granules, such as potato and green banana, are known to resist attack by a - amylase. This is probably related to the crystalline nature of the starch (i.e., crystalline regions of the starch granule are less susceptible to attack by acid and enzymes than the amorphous regions). Gelatinization normally occurs during cooking and food processing, although the extent is dependent on the moisture content of the food product and may not be complete in water-limited systems (e.g. sugar cookies). Gelatinized starch is much more rapidly digested by enzymes than is raw starch. Gelatinized potato and green banana starch are digested by a -amylases.  www.BrainKart.com www.canestar.com www.nurseinfo.in High-amylose maize starches have high gelatinization temperatures, requiring temperatures that are often not reached in conventional cooking practices (154-171°C) before the granules are completely disrupted. As a result, undigested starch granules have been observed in the effluent from ileostomates fed a meal containing high amylose maize. These starches offer an opportunity to manipulate the amount of resistant starch present in food products. 3. RS3 - Retrograded starch: The amylose and amylopectin components of starch undergo the process of retrogradation in a time dependent process after starch has been gelatinized/cooked. The rate at which amylose retrogrades is much higher than that for amylopectin which has much shorter chain lengths. Amylose can be retrograded to a form that resists dispersion in water and digestion with a-amylase. This form of resistant starch can be generated during food processing. There is currently great interest in resistant starch because of is potential use as a food ingredient to increase the dietary fibre content of foods and also because it may be possible to manipulate the amount of resistant starch in food products through processing conditions. Sugar alcohols (alditols, polyols) Monosaccharides and disaccharides in which the aldose and ketose functional groups have been reduced to hydroxyl groups are known as sugar alcohols (alditols, polyols). Sugar alcohols, such as sorbitol, occur in small amounts in fruits. Due to their physicochemical properties and relative sweetness, sugar alcohols have found use as bulk sweeteners. Xylitol has a negative heat of solubility which produces a cooling sensation when used in products such as chewing gum. The sugar alcohols undergo limited absorption in the small intestine, and this can  www.BrainKart.com www.canestar.com www.nurseinfo.in lead to laxative effects in many people when large amounts (50 grams or more at one time) are consumed. There appear to be no other health risks associated with the consumption of sugar alcohols. RECOMMENDED DAILY ALLOWANCE (RDA) "The World Health Organization and the Food and Agriculture Organization, jointly recommend the national dietary guidelines. They recommend that carbohydrates should give us 55 to 75 percent of the total energy requirements out of which only 10 percent should be directly from sugars or simpler carbohydrates. A general recommendation of most dietary guidelines suggests that complex carbohydrates and simpler carbohydrates, which are “nutrition rich”, should make up the majority of carbohydrate consumption. Examples are fruits (glucose and fructose), milk, and milk products (lactose). The recommended foods do not include sugary drinks, added sugary high calorie foods and candies. DIETARY SOURCES Common sources of naturally occurring carbohydrates include:  Fruits  Vegetables  Milk  Nuts  Grains  www.BrainKart.com www.canestar.com www.nurseinfo.in  Seeds  Legumes Types of carbohydrates There are three main types of carbohydrates: Sugar. Sugar is the simplest form of carbohydrate and occurs naturally in some foods, including fruits, vegetables, milk and milk products. Types of sugar include fruit sugar (fructose), table sugar (sucrose) and milk sugar (lactose). Starch. Starch is a complex carbohydrate, meaning it is made of many sugar units bonded together. Starch occurs naturally in vegetables, grains, and cooked dry beans and peas. Fiber. Fiber also is a complex carbohydrate. It occurs naturally in fruits, vegetables, whole grains, and cooked dry beans and peas. Common foods with carbohydrates include  Grains, such as bread, noodles, pasta, crackers, cereals, and rice  Fruits, such as apples, bananas, berries, mangoes, melons, and oranges  Dairy products, such as milk and yogurt  Legumes, including dried beans, lentils, and peas  Snack foods and sweets, such as cakes, cookies, candy, and other desserts  www.BrainKart.com www.canestar.com www.nurseinfo.in  Juices, regular sodas, fruit drinks, sports drinks, and energy drinks that contain sugar  Starchy vegetables, such as potatoes, corn, and peas FUNCTIONS OF CARBOHYDRATE  Carbohydrates provide energy and regulation of blood glucose.  It will prevent the degradation of skeletal muscle and other tissues such as the heart, liver, and kidneys.  It prevent the breakdown of proteins for energy.  Carbohydrates also help with fat metabolism. If the body has enough energy for its immediate needs, it stores extra energy as fat.  Carbohydrates are an important component of many industries like textile, paper, lacquers and breweries.  Detoxification of physiological importance is carried out to some extent with carbohydrate derivatives.  Agar is polysaccharide used in culture media, laxative and food.  Carbohydrates form a part of genetic material like DNA and RNA in the form of deoxyribose and ribose sugars.  Hyaluronic acid found in between joints acts as synovial fluid and provides frictionless movement.  They help make up the body mass by being included in all the parts of the cell and tissues.  Adequate storage of hepatic glycogen helps in detoxifying a normal liver.  www.BrainKart.com www.canestar.com www.nurseinfo.in  They form components of bio-molecules which have a key role in blood clotting, immunity, fertilization etc.  Carbohydrates are basically the main fibre of the diet or provide the bulk fibre for better digestion.  Carbohydrates help clear gut and prevent constipation.  Starch is the form the food is stored in plants.  It provides sweetness to foods.  Pectine and Hemiceliulose are the structural carbohydrate in plant cell walls.  It plays important roles in cellular recognition processes.  Chitin forms the cell wall of fungi and the outer schelitone of insects.  Murine is a structural carbohydrate in bacterial cell wall. ENERGY UNIT OF ENERGY – Kcal Food that we eat gives us energy to go through our day. It gives us energy by providing energy to the cells inside our body. Carbohydrates in food are used first. When they are all used up, the body then uses fats, and then proteins as energy sources. So carbohydrates, fats and proteins provide energy to our bodies through the foods that we eat. The energy in the food that we it is measured in units of kilocalories or Calories. The Calorie (Cal, with an uppercase C) used to measure the nutrition in food is actually 1000 calories (cal) (with a lowercase c) or 1 kilocalorie (kcal). While the Calorie unit is used widely in the U.S., the  www.BrainKart.com www.canestar.com www.nurseinfo.in kilojoule (kJ) is in widespread use internationally. The conversion factors for calories, kilocalories, joules, kilojoules, and Calories are as follows: Energy Values used in Nutrition 1000cal = 1 kcal = 1 Cal 4184 J = 4.184 kJ = 1 Cal CALCULATING ENERGY FROM FOOD SOURCE Step 1: List the known quantities and plan the problem. Known Energy per gram  Fat = 9 kcal/g (Cal/g)  Carbohydrate = 4 kcal/g (Cal/g)  Protein = 4 kcal/g (Cal/g) Grams  Fat = 11 g  Carbohydrate = 12 g  Protein = 5 g The amount of grams of each energy source (fat, carbohydrate, and protein) and the amount of energy per gram of each energy source. Multiply the grams by the Energy per gram to obtain the Energy. Note: The Energy per gram is the conversion factor. It should be multiplied in such a way that the energy is on top and the grams are on bottom because you want your final answer to be energy in Cal or kcal or kJ.  www.BrainKart.com www.canestar.com www.nurseinfo.in Step 2: Solve. Energy from Fat: 11 g x 9 kcal/g = 99 kcal = 99 Cal Convert to kJ 99 Cal x 4.184kJ/Cal = 414.216 kJ= 414kJ Energy from Carbohydrate: 12 g x 4 kcal/g = 48 kcal = 48 Cal Convert to kJ 48 Cal x 4.184kJ/Cal = 200.832 kJ = 201 kJ Energy from Protein: 5 g x 4 kcal/g = 20 kcal = 20 Cal Convert to kJ 20 Cal x 4.184kJ/Cal = 83.68 kJ = 84 kJ BASAL METABOLIC RATE (BMR) Definition of BMR Basal metabolic rate is the energy released when the subject is at complete mental and physical rest i.e. in a room with comfortable temperature and humidity, awake and sitting in a reclining position, 10- 12 hours after the last meal. It is essentially the minimum energy required to maintain the heart rate, respiration, kidney function etc.  www.BrainKart.com www.canestar.com www.nurseinfo.in The B.M.R. of an average Indian man is 1750-1900 Kcal/day. In terms of oxygen consumption it would amount to about 15 litre/hr. Heavily built persons have higher BMRs, but the BMR per unit body weight is higher in the smaller built individuals ex. although the BMR of a man as given above is higher than that of a boy of 15 kg body weight that spends about 800 Kcal/day for its basal metabolism, the BMR per kg/day of man is about 30 Kcal, while that of the boy is about 53 Kcal/kg/day. The variable that correlates most with the BMR is the surface area of the body. Thus in case of both boy and man the BMR is around 1000 Kcal/m2 body surface/day. In case of human beings body surface area can be calculated by the following formula: S = 0.007184 x W0.425 x h0.725 where S = surface area in sq metres W = body weight in kg and H = height in cm Significance of BMR The determination of BMR is the principal guide for diagnosis and treatment of thyroid disorders.  www.BrainKart.com www.canestar.com www.nurseinfo.in If BMR is less than 10% of the normal, it indicates moderate hypothyroidism. In severe hypothyroidism, the BMR may be decreased to 40 to 50 percent below normal. BMR aids to know the total amount of food or calories required to maintain body weight. The BMR is low in starvation, under nutrition, hypothalamic disorders, Addison’s disease and lipoid nephrosis. The BMR is above normal in fever, diabetes insipidus, leukemia and polycythemia. FACTOR AFFECTING BMR Factors that influence basal metabolic rate are:  Body size: Metabolic rate increases as weight, height, and surface area increase.  Body composition: Fat tissue has a lower metabolic activity than muscle tissue.  As lean muscle mass increases, metabolic rate increases.  Gender: The basal metabolic rate (BMR) averages 5 to 10 percent lower in women than in men. This is largely because women generally possess more body fat and less muscle mass than men of similar size.  Age: A decrease in lean muscle mass during adulthood results in a slow, steady decline of roughly 0 3 percent per year in BMR after  www.BrainKart.com www.canestar.com www.nurseinfo.in the age of about 30. This can be largely avoided by strength training throughout adulthood.  Climate and body temperature: The BMR of people in tropical climates is generally 5 to 20 percent higher than their counterparts living in more temperate areas because it takes energy to keep the body cool. Exercise performed in hot weather also imposes an additional metabolic load. Body fat content and effectiveness of clothing determine the magnitude of increase in energy metabolism in cold environments; it takes energy to keep the body warm if you work or exercise in very cold weather.  Hormonal levels: Thyroxine (T4), the key hormone released by the thyroid glands has a significant effect upon metabolic rate. Hypothyroidism is relatively common, especially in women near or after menopause. Everyone with a weight problem should have their thyroid function checked by their doctor and treated appropriately if it turns out to be low.  Health: Fever, illness, or injury may increase resting metabolic rate two-fold.  www.BrainKart.com www.canestar.com www.nurseinfo.in UNIT – 3 PROTEINS COMPOSITION Proteins are large molecules consisting of many amino-acids connected by “peptide linkages”. Peptide bond is produced when carboxyl radical of one amino acid reacts with the amino (-NH2) group of the other amino acid. The basic structural formula of amino acids is shown in Fig. 4.1. It consists of one alpha (a) carbon atom that is associated with an amino group (-NH2) with a potential (+) charge, a carboxyl group with a (-) charge, a hydrogen atom and a side chain “R” that varies in the different amino acids. There are usually 20 amino acids found in proteins (for structural formulae of the amino acids, any book of biochemistry may be  www.BrainKart.com www.canestar.com www.nurseinfo.in consulted). These twenty amino-acids are divided into 7 groups (Table 4.1). All the 20 amino acids need not be present in a given protein. The side chains (R) of amino acids are responsible for the different properties, such as, water solubility, interaction with other amino acids etc. of the amino acids. The amino acids possessing -CH3 group are much less soluble in water and they are called “hydrophobic” amino acids, e.g., leucine, isoleucine, valine. The amino acids that are water soluble are called “hydrophilic” amino- acids, e.g., lysine (+ charge) and aspartic acid (-charge). The sulfhydryl group (-SH) of cysteine can interact with the -SH group of other cysteine in the protein chain to make a disulfide linkage (S-S). The H atoms of hydroxyl group (-OH) or carboxyl group of the “R ‘ chain can make hydrogen bonding with other amino acids in the protein chain. The bonds are required for stabilizing the structure of protein molecules.  www.BrainKart.com www.canestar.com www.nurseinfo.in EIGHT ESSENTIAL AMINOACIDS Amino acids are organic compounds composed of a central carbon, a unique side chain, at least one amino group and at least one carboxylic acid group. The human body uses amino acids to produce proteins, perform critical metabolic functions in the formation of other molecules and to produce energy. Some amino acids are synthesized by the human body, but the essential amino acids must be obtained from food. Essential Amino Acids Nutritionally essential, or indispensable, amino acids cannot be made by the human body and must be obtained from food. These amino acids are not optional, as a lack of sufficient bioavailability has adverse health effects. In the 1930s, the essentiality of eight amino acids was established. The eight original essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Food sources of amino acids are protein-rich foods. As these foods are digested and assimilated the peptide bonds that link amino acids chains to form the proteins are broken. There are many types of essential amino acids, including: Lysine Lysine plays a vital role in building muscle, maintaining bone strength, aiding recovery from injury or surgery, and regulating hormones, antibodies, and enzymes. It may also have antiviral effects. Histidine  www.BrainKart.com www.canestar.com www.nurseinfo.in Histidine facilitates growth, the creation of blood cells, and tissue repair. It also helps maintain the special protective covering over nerve cells, which is called the myelin sheath. The body metabolizes histidine into histamine, which is crucial for immunity, reproductive health, and digestion. The results of a study that recruited women with obesity and metabolic syndrome suggest that histidine supplements may lower BMI and insulin resistance. Threonine Threonine is necessary for healthy skin and teeth, as it is a component in tooth enamel, collagen, and elastin. It helps aid fat metabolism and may be beneficial for people with indigestion, anxiety, and mild depression. Methionine Methionine and the nonessential amino acid cysteine play a role in the health and flexibility of skin and hair. Methionine also helps keep nails strong. It aids the proper absorption of selenium and zinc and the removal of heavy metals, such as lead and mercury. Valine Valine is essential for mental focus, muscle coordination, and emotional calm. People may use valine supplements for muscle growth, tissue repair, and energy. Deficiency may cause insomnia and reduced mental function. Isoleucine  www.BrainKart.com www.canestar.com www.nurseinfo.in Isoleucine helps with wound healing, immunity, blood sugar regulation, and hormone production. It is primarily present in muscle tissue and regulates energy levels. Leucine Leucine helps regulate blood sugar levels and aids the growth and repair of muscle and bone. It is also necessary for wound healing and the production of growth hormone. Phenylalanine Phenylalanine helps the body use other amino acids as well as proteins and enzymes. The body converts phenylalanine to tyrosine, which is necessary for specific brain functions. Phenylalanine deficiency, though rare, can lead to poor weight gain in infants. It may also cause eczema, fatigue, and memory problems in adults. Phenylalanine is often in the artificial sweetener aspartame, which manufacturers use to make diet sodas. Large doses of aspartame can increase the levels of phenylalanine in the brain and may cause anxiety and jitteriness and affect sleep. People with a rare genetic disorder called phenylketonuria (PKU) are unable to metabolize phenylalanine. As a result, they should avoid consuming foods that contain high levels of this amino acid. Tryptophan Tryptophan is necessary for proper growth in infants and is a precursor of serotonin and melatonin. Serotonin is a neurotransmitter that  www.BrainKart.com www.canestar.com www.nurseinfo.in regulates appetite, sleep, mood, and pain. Melatonin also regulates sleep. Tryptophan is a sedative, and it is an ingredient in some sleep aids. One study indicates that tryptophan supplementation can improve mental energy and emotional processing in healthy women. Tryptophan deficiency can cause a condition called pellagra, which can lead to dementia, skin rashes, and digestive issues. FUNCTIONS Proteins are molecules made of amino acids. They are coded for by our genes and form the basis of living tissues. They also play a central role in biological processes. For example, proteins catalyse reactions in our bodies, transport molecules such as oxygen, keep us healthy as part of the immune system and transmit messages from cell to cell. Proteins perform essential functions throughout the systems of the human body. These long chains of amino acids are critically important for:  catalyzing chemical reactions  synthesizing and repairing DNA  transporting materials across the cell  receiving and sending chemical signals  responding to stimuli  providing structural support Protein Synthesis  www.BrainKart.com www.canestar.com www.nurseinfo.in A gene is a segment of a DNA molecule that contains the instructions needed to make a unique protein. All of our cells contain the same DNA molecules, but each cell uses a different combination of genes to build the particular proteins it needs to perform its specialised functions. Protein synthesis has 2 main stages. The 1st stage is known as transcription, where a messenger molecule (mRNA) is formed. This molecule is transcribed from the DNA molecule and carries a copy of the information needed to make a protein. In the 2nd stage, the mRNA molecule leaves the nucleus for the cytoplasm where the cell’s ribosomes read the information and start to assemble a protein in a process called translation During translation, the ribosomes read the mRNA sequence of bases 3 at a time. These 3-letter combinations (called codons) each code a particular amino acid. For example, the base sequence TTT codes for the amino acid lysine. There are 4 bases (adenine, thymine, guanine and cytosine) and therefore 64 (43) possible codons specified using some combination of 3 bases. However, only 20 amino acids are required to build all of the proteins in our bodies (some amino acids are specified by more than 1 codon). It is the particular sequence of amino acids that determines the shape and function of the protein. Protein synthesis, like many other biological processes, can be affected by environmental factors. These include maternal nutrition, temperaturestress, oxygen levels and exposure to chemicals Different Types of proteins  www.BrainKart.com www.canestar.com www.nurseinfo.in There are many different types of proteins in our bodies. They all serve important roles in our growth, development and everyday functioning. Here are some examples:  Enzymes are proteins that facilitate biochemical reactions, for example, pepsin is a digestive enzyme in your stomach that helps to break down proteins in food.  Antibodies are proteins produced by the immune system to help remove foreign substances and fight infections.  DNA-associated proteins regulate chromosome structure during cell division and/or play a role in regulating gene expression, for example, histones and cohesin proteins  Contractile proteins are involved in muscle contraction and movement, for example, actin and myosin  Structural proteins provide support in our bodies, for example, the proteins in our connective tissues, such as collagen and elastin.  Hormone proteins co-ordinate bodily functions, for example, insulin controls our blood sugar concentration by regulating the uptake of glucose into cells.  Transport proteins move molecules around our bodies, for example, haemoglobin transports oxygen through the blood. Alternative roles for proteins Each protein has a specific role in our body. However, scientists have discovered that some proteins perform more than 1 role. Hormones  www.BrainKart.com www.canestar.com www.nurseinfo.in Some proteins function as chemical-signaling molecules called hormones. These proteins are secreted by endocrine cells that act to control or regulate specific physiological processes, which include growth, development, metabolism, and reproduction. For example, insulin is a protein hormone that helps to regulate blood glucose levels. Other proteins act as receptors to detect the concentrations of chemicals and send signals to respond. Some types of hormones, such as estrogen and testosterone, are lipid steroids, not proteins. DIETARY SOURCES Protein foods Some food sources of dietary protein include:  lean meats – beef, lamb, veal, pork, kangaroo  poultry – chicken, turkey, duck, emu, goose, bush birds  fish and seafood – fish, prawns, crab, lobster, mussels, oysters, scallops, clams  eggs  dairy products – milk, yoghurt (especially Greek yoghurt), cheese (especially cottage cheese)  nuts (including nut pastes) and seeds – almonds, pine nuts, walnuts, macadamias, hazelnuts, cashews, pumpkin seeds, sesame seeds, sunflower seeds  legumes and beans – all beans, lentils, chickpeas, split peas, tofu.  www.BrainKart.com www.canestar.com www.nurseinfo.in Some grain and cereal-based products are also sources of protein, but are generally not as high in protein as meat and meat-alternative products. PROTEIN REQUIREMENT – RDA India’s protein consumption is much lower than the 48 gms/day that is recommended by the Indian Council of Medical Research (ICMR). The recommended dietary allowance of protein for an average Indian adult is 0.8 to 1 gm per kg body weight, however, the average intake is about 0.6 gm per kg body weight.  www.BrainKart.com www.canestar.com www.nurseinfo.in UNIT – 4 FATS CLASSIFICATION – SATURATED AND UNSATURATED Fatty acids are classified according to the presence and number of double bonds in their carbon chain. Saturated fatty acids (SFA) contain no double bonds, monounsaturated fatty acids (MUFA) contain one, and polyunsaturated fatty acids (PUFA) contain more than one double bond. Both length and saturation of fatty acids affect the arrangement of the membrane in our body cells and thereby its fluidity. Shorter chain fatty acids and ones with greater unsaturation are less stiff and less viscous, making the membranes more flexible. This influences a range of important biological functions Classification of Fat Saturated fat Saturated fat is solid at room temperature, which is why it is also known as "solid fat." It is mostly in animal foods, such as milk, cheese, and meat. Poultry and fish have less saturated fat than red meat. Saturated fat is also in tropical oils, such as coconut oil, palm oil, and cocoa butter. Foods made with butter, margarine, or shortening (cakes, cookies, and other desserts) have a lot of saturated fat. Saturated fat can raise your cholesterol. A healthy diet has less than 10% of daily calories from saturated fat. Trans fat  www.BrainKart.com www.canestar.com www.nurseinfo.in This is a fat that has been changed by a process called hydrogenation. This process increases the shelf life of fat and makes the fat harder at room temperature. Harder fat makes crispier crackers and flakier pie crusts. Trans fat can raise your cholesterol, so eat as little trans fat as possible. You'll find it in:  Processed foods.  Snack foods, such as chips and crackers.  Cookies.  Some margarine and salad dressings. Foods made with shortening and partially hydrogenated oils. Unsaturated fat Unsaturated fat is liquid at room temperature. It is mostly in oils from plants. If you eat unsaturated fat instead of saturated fat, it may help improve your cholesterol levels. Try to eat mostly unsaturated fats. Monounsaturated fat and polyunsaturated fat are types of unsaturated fat. Monounsaturated fat: This fat is in avocado, nuts, and vegetable oils, such as canola, olive, and peanut oils. Eating foods that are high in monounsaturated fats may help lower your "bad" LDL cholesterol. Monounsaturated fats may also keep "good" HDL cholesterol levels high. But eating more unsaturated fat without cutting back on saturated fat may not lower your cholesterol. Polyunsaturated fat: This type of fat is mainly in vegetable oils such as safflower, sunflower, sesame, soybean, and corn oils. Polyunsaturated fat is also the main fat found in seafood. Eating polyunsaturated fat in  www.BrainKart.com www.canestar.com www.nurseinfo.in place of saturated fat may lower LDL cholesterol. The two types of polyunsaturated fats are omega-3 and omega-6 fatty acids. Omega-3 fatty acids are found in foods from plants like soybean oil, canola oil, walnuts, and flaxseed. They are also found in fatty fish and shellfish as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Salmon, anchovies, herring, sardines, Pacific oysters, trout, Atlantic mackerel, and Pacific mackerel are high in EPA and DHA and lower in mercury. A healthy diet includes 8 ounces or more of these types of fish a week, averaging 250 mg a day of these omega-3 fatty acids.footnote2 Omega-6 fatty acids are found mostly in liquid vegetable oils like soybean oil, corn oil, and safflower oil. Total fat Total fat includes saturated, polyunsaturated, monounsaturated, and trans fat. Review the nutrition facts label on food packaging to learn the total fat, saturated fat, and trans fat. Food labels are not required to list monounsaturated and polyunsaturated fat. Classification of unsaturated fatty acids (cis and trans) Unsaturated fatty acids can also be classified as "cis" (bent form) or "trans" (straight form), depending on whether hydrogen is bound on the same, or on the opposite side of the molecule. Most naturally occurring unsaturated fatty acids are found in cis form. Trans fatty acids (TFA) can be divided in two groups: artificial TFA (industrial) and natural  www.BrainKart.com www.canestar.com www.nurseinfo.in TFA (ruminant). Industrial TFA are produced by humans and can be found in products containing vegetable oils/fats that have undergone a hardening process known as partial hydrogenation. Small amounts of TFA can also be generated during the deodorization of vegetable oils/fats, the final step in edible oil/fat refining. A range of TFA isomers (varieties) exist and are structurally different in the position of the double bond along the fatty acid molecule. Classification of PUFA (omega fatty acids) PUFA can be further categorised into three main families according to the position of the first double bond starting from the methyl-end (the opposite side of the glycerol molecule) of the fatty acid chain:  Omega-3 (or n-3) fatty acids have the first double bond at the third carbon atom and include mainly alpha linolenic acid (ALA) and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).  Omega-6 (or n-6) fatty acids have the first double bond at the sixth carbon atom and include mainly linoleic acid (LA) and its derivative arachidonic acid (AA).  Omega-9 (or n-9) fatty acids have the first double bond at the ninth carbon atom and include mainly oleic acid. Typical dietary Common name Symbol (*) source  www.BrainKart.com www.canestar.com www.nurseinfo.in Saturated fatty acids Butyric C4:0 Butterfat Caprylic C8:0 Palm kernel oil Capric C10:0 Coconut oil Lauric C12:0 Coconut oil Butterfat, coconut Myristic C14:0 oil Palmitic C16:0 Most fats and oils Stearic C18:0 Most fats and oils Arachidic C20:0 Lard, peanut oil Monounsaturated fatty acids  www.BrainKart.com www.canestar.com www.nurseinfo.in Palmitoleic C16:1 n-7 Most fats and oils C18:1 n-9 Oleic Most fats and oils (cis) Hydrogenated C18:1 n-9 Elaidic vegetable oils, (trans) butterfat, beef fat PUFA C18:2 n-6 Most vegetable Linoleic (all cis) oils Soybean oil, C18:3 n-3 Alpha-linolenic canola/rapeseed (all cis) oil Blackcurrant seed oil, borage oil, Gamma-linolenic C18:3 n-6 evening primrose oil C20:4 n-6 Pork fat, poultry Arachidonic (all cis) fat  www.BrainKart.com www.canestar.com www.nurseinfo.in C20:5 n-3 Eicosapentaenoic Fish oils (all cis) C22:6 n-3 Docosahexaenoic Fish oils (all cis) CALORIFIC VALUE Calorific value is the amount of energy which is present in a food or fuel and it’s determined by measuring the heat produced by complete combustion of it with oxygen of specific quantity. It is measured in kcal/g. Or it is defined as the energy value of food and fuel indicating how much energy gained by metabolism of the human body. Fats:- Fats are the slowest form of energy and lately digest. Some foods like sausages, potato contain higher calories and lower vitamins and minerals so that as compared to above two fats have high calorific value. To calculate the calorific value any macromolecule: The formula used will be heat/kilogram Heat calculated in the above formula will be measured in kilojoules kilogram which is equal to total combustion in kg. The total energy value of a food product results from the addition of the energy content of each nutrient components. These are defined as follows:  www.BrainKart.com www.canestar.com www.nurseinfo.in 1 g fat 37 kJ (9 kcal) 1 g carbohydrates 17 kJ (4 kcal) 1 g protein 17 kJ (4 kcal) 1 g alcohol (ethanol) 29 kJ (7 kcal) 1 g polyhydric alcohols (polyols) 10 kJ (2.4 kcal) 1 g dietary fibre 8 kJ (2 kcal) FUNCTIONS OF FATS Fats serve useful functions in both the body and the diet. In the body, fat functions as an important depot for energy storage, offers insulation and protection, and plays important roles in regulating and signaling. Large amounts of dietary fat are not required to meet these functions, because most fat molecules can be synthesized by the body from other organic molecules like carbohydrate and protein (with the exception of two essential fatty acids). However, fat also plays unique roles in the diet, including increasing the absorption of fat-soluble vitamins and contributing to the flavor and satisfaction of food. Dietary fats are not just a source of energy; they function as structural building blocks of the body, carry fat-soluble vitamins, are involved in vital physiological processes in the body, and are indispensable for a number of important biological functions including growth and  www.BrainKart.com www.canestar.com www.nurseinfo.in development. The importance of dietary fats is explained in more detail below. Provision of energy Fats are a source of energy in the human diet, together with carbohydrates and proteins, the other two main macronutrients. Fat is the most concentrated source providing 9 kcal per 1 gram consumed, which is more than double the energy content of protein or carbohydrate (4 kcal per gram) and more than quadruple the energy content of fibre (2 kcal per gram). Fat can be stored in the body’s fat tissue, which releases fatty acids when energy is required. Structural component The membranes around the cells in our body physically separate the inside from the outside of the cell, and control the movement of substances in and out of the cells. They are mainly made of phospholipids, triglycerides and cholesterol. Both length and saturation of the fatty acids from phospholipids and triglycerides affect the arrangement of the membrane and thereby its fluidity. Shorter chain fatty acids and unsaturated fatty acids are less stiff and less viscous, making the membranes more flexible. This influences a range of important biological functions such as the process of endocytosis in which a cell wraps itself around a particle to allow its uptake.1 The brain is very rich in fat (60%) and has a unique fatty acid composition; docosahexaenoic acid (DHA) is the major brain fatty acid. The lipids of the retina also contain very high concentrations of DHA.2 Carrier of vitamins  www.BrainKart.com www.canestar.com www.nurseinfo.in In the diet, fat is a carrier for the fat-soluble vitamins A, D, E and K, and supports their absorption in the intestine. Consuming sufficient amounts of fatty foods that contain these vitamins is thus essential for adequate intake of these micronutrients. DIETARY SOURCES OF FATS AND FATTY ACIDS Dietary Source of Fat  Red meat -- beef, lamb, pork  Skin-on chicken and other poultry  Whole-milk dairy products like milk, cheese, and ice cream  Butter  Eggs  Palm and coconut oils  Flaxseed, corn, soybean, and sunflower oil  Walnuts  Flaxseeds  Salmon, tuna, and other fatty fish FAT REQUIREMENTS – RDA RDA The dietary reference intake (DRI) for fat in adults is 20% to 35% of total calories from fat. That is about 44 grams to 77 grams of fat per day if you eat 2,000 calories a day. It is recommended to eat more of some types of fats because they provide health benefits.  Monounsaturated fat: 15% to 20%  www.BrainKart.com www.canestar.com www.nurseinfo.in  Polyunsaturated fat: 5% to 10%  Saturated fat: less than 10%  Trans fat: 0%  Cholesterol: less than 300 mg per day  www.BrainKart.com www.canestar.com www.nurseinfo.in UNIT – 5 VITAMINS CLASSIFICATION – FAT SOLUBLE AND WATER SOLUBLE A vitamin is an organic molecule (or related set of molecules) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrients cannot be synthesized in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the diet. Vitamin C can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second.  www.BrainKart.com www.canestar.com www.nurseinfo.in Classification of vitamins as water-soluble or fat-soluble Vitamins are classified as either water-soluble or fat-soluble. In humans there are 13 vitamins: 4 fat- soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Water-soluble vitamins dissolve easily in water and, in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin consumption. Because they are not as readily stored, more consistent intake is important. Fat-soluble vitamins are absorbed through the intestinal tract with the help of lipids (fats). Vitamins A and D can accumulate in  www.BrainKart.com www.canestar.com www.nurseinfo.in the body, which can result in dangerous hypervitaminosis. Fat-soluble vitamin deficiency due to malabsorption is of particular significance in cystic fibrosis. Water soluble vitamins Vitamins are often categorized based on their solubility. Most of them dissolve in water and are called water-soluble vitamins. In contrast, there are only four fat-soluble vitamins, which dissolve in oil (liquid fat). Nine water-soluble vitamins are found in the human diet:  Vitamin B1 (thiamine)  Vitamin B2 (riboflavin)  Vitamin B3 (niacin)  Vitamin B5 (pantothenic acid)  Vitamin B6  Vitamin B7 (biotin)  Vitamin B9  Vitamin B12 (cobalamin)  www.BrainKart.com www.canestar.com www.nurseinfo.in  Vitamin C Unlike the fat-soluble vitamins, water-soluble vitamins are generally not stored in the body. Thiamine (Vitamin B1) Thiamine, also known as vitamin B1, was the first water-soluble vitamin to be described scientifically. Types Many forms of thiamine exist, including:  Thiamine pyrophosphate: Also known as thiamine diphosphate, thiamine pyrophosphate is the most abundant form of thiamine in your body. It is also themain form found in whole foods.  Thiamine triphosphate: This form is found in animal-sourced foods, but is less abundant than thiamine pyrophosphate. It is believed to represent less than 10% of the total thiamine found in animal tissues.  www.BrainKart.com www.canestar.com www.nurseinfo.in  Thiamine mononitrate: A synthetic form of thiamine often added to animal feed or processed food.  Thiamine hydrochloride: The standard, synthetic form of thiamine used insupplements. Role and Function Like the other B vitamins, thiamine serves as a coenzyme in the body. This applies to all its active forms, but thiamine pyrophosphate is the most important one. Coenzymes are small compounds that help enzymes trigger chemical reactions that otherwise wouldn’t happen on their own. Thiamine is involved in many essential chemical reactions. For instance, it helps convert nutrients into energy and supports sugar formation. Dietary sources  www.BrainKart.com www.canestar.com www.nurseinfo.in The richest dietary sources of thiamine include nuts, seeds, whole grains, liver and pork. Sources: Lamb liver, sunflower seeds, pork, oats, hazelnuts. www.canestar.com www.nurseinfo.in www.BrainKart.com Deficiency Deficiency is uncommon, but high blood sugar levels may increase thiamine elimination via urine, raising its requirements and the risk of deficiency. In fact, thiamine levels may be reduced by 75–76% in people with type 1 and type 2 diabetes. People with alcoholism are also at an increased risk for deficiency because of a poor diet and impaired thiamine absorption. Serious deficiency may lead to disorders known as beriberi and Wernicke-Korsakoff syndrome. These disorders are associated with a range of symptoms, including anorexia, weight loss, impaired neural function, mental problems, muscle weakness and heart enlargement. Side Effects and Toxicity Thiamine is considered safe. There are no reports of adverse effects after the intake of high amounts of thiamine from food or supplements. www.canestar.com www.nurseinfo.in www.BrainKart.com This is partly because excess thiamine is quickly excreted from the body in urine. As a result, the tolerable upper intake level for thiamine has not been established. However, this does not rule out possible symptoms of toxicity at very high intakes. Benefits of Supplements No good evidence shows that thiamine supplements benefit healthy people who get adequate amounts from their diets. But for those with high blood sugar levels or a poor thiamine status, high-dose supplements may reduce blood sugar and blood pressure. Additionally, low thiamine intake has been associated with various other disorders, such as glaucoma, depression and fibromyalgia. However, more research is needed before strong conclusions can be made. Summary of Thiamine Thiamine, also known as vitamin B1, was the first B vitamin to be discovered. www.canestar.com www.nurseinfo.in www.BrainKart.com Like the other B vitamins, thiamine acts as a coenzyme. It plays an essential role in many metabolic processes, including those that convert nutrients into energy. The richest dietary sources of thiamine include liver, pork, seeds and whole-grain cereals. Deficiency is uncommon, but diabetes and excessive alcohol intake increase the risk. Serious deficiency may result in diseases such as beriberi and Wernicke- Korsakoff syndrome. High-dose thiamine supplements do not seem to have any adverse effects and the tolerable upper intake level hasn’t been established. However, supplements do not appear to have any benefits for those who get adequate amounts from their diets. Riboflavin (Vitamin B2) Riboflavin is the only water-soluble vitamin used as a food coloring. In fact, it is named for its color — the Latin word flavus means “yellow.” Types In addition to riboflavin, dietary substances known as flavoproteins release riboflavin during digestion. www.canestar.com www.nurseinfo.in www.BrainKart.com Two of the most common flavoproteins are flavin adenine dinucleotide and flavin mononucleotide. They are found in a wide range of foods. Role and Function Riboflavin functions as a coenzyme in various chemical reactions. Like thiamine, it is involved in the conversion of nutrients into energy. It is also required in the conversion of vitamin B6 to its active form, and in the conversion of tryptophan to niacin (vitamin B3). Sources Lamb liver, beef liver, pork liver, hard goat cheese, almonds Yeast extract spread is also exceptionally rich in riboflavin, containing around 18 mg in every 100 grams. Other good sources of riboflavin include eggs, leafy vegetables, broccoli, milk, legumes, mushrooms and meat. Recommended Intake The table below shows the RDA or adequate intake for riboflavin. These values represent the daily intake sufficient to meet the requirements of most people. RDA (mg/day) www.canestar.com www.nurseinfo.in www.BrainKart.com Infants 0–6 months 0.3* 7–12 months 0.4* Children 1–3 years 0.5 4–8 years 0.6 9–13 years 0.9 Women 14–18 years 1 19+ years 1.1 Men 14+ years 1.3 Pregnancy 1.4 Lactation 1.6 *Adequate intake Deficiency Riboflavin deficiency is very rare in developed countries. However, a poor diet, old age, lung diseases and alcoholism may increase the risk. Severe deficiency results in a condition known as ariboflavinosis, which is characterized by a sore throat, inflamed tongue, anemia, as well as skin and eye problems. www.canestar.com www.nurseinfo.in www.BrainKart.com It also impairs the metabolism of vitamin B6 and the conversion of tryptophan to niacin. Side Effects and Toxicity High intake of dietary or supplemental riboflavin has no known effects of toxicity. Absorption becomes less efficient at higher doses. Also, very small amounts are stored in body tissues and excess riboflavin is flushed out of the body with urine. As a result, the safe upper intake level of riboflavin has not been established. Benefits of Supplements In most cases, riboflavin supplements do not have any benefits for people who already get enough from food. Yet, low-dose riboflavin supplements may potentially reduce blood pressure and lower the risk of heart disease in people who are genetically predisposed to them. It’s thought to do this by decreasing high homocysteine levels in those with two copies of the gene MTHFR 677TT. Higher doses of riboflavin, such as 200 mg twice a day, may also reduce migraines. Summary of Riboflavin Riboflavin, also known vitamin B2, is a coenzyme with various essential functions. For instance, it is required for converting nutrients to energy. www.canestar.com www.nurseinfo.in www.BrainKart.com Found in various foods, its richest sources include liver, meat, dairy products, eggs, leafy vegetables, almonds and legumes. Deficiency is virtually unknown among healthy people in Western countries, although diseases and poor lifestyle habits may increase the risk. High-dose riboflavin supplements are not known to have any adverse effects, but they usually only benefit those who are deficient. However, evidence suggests they may reduce migraines or lower the risk of heart disease in genetically susceptible people. Niacin (Vitamin B3) Niacin, also known as vitamin B3, is the only B vitamin your body can produce from another nutrient — the amino acid tryptophan. Types Niacin is a group of related nutrients. The most common forms are: Nicotinic acid: The most common form in supplements. Also found in both plant- and animal-sourced foods. High-dose nicotinic acid supplements may cause a condition called niacin flush. Nicotinamide (niacinamide): Found in supplements and foods. The compound nicotinamide riboside also has vitamin B3 activity. It is found in trace amounts in whey protein and baker’s yeast. www.canestar.com www.nurseinfo.in www.BrainKart.com Role and Function All dietary forms of niacin are eventually converted into nicotinamide adenine dinucleotide (NAD+) or nicotinamide adenine dinucleotide phosphate (NADP+), which act as coenzymes. Like the other B vitamins, it functions as a coenzyme in the body, playing an essential role in cellular function and acting as an antioxidant. One of its most important roles is to drive a metabolic process known as glycolysis, the extraction of energy from glucose (sugar). Dietary Sources Niacin is found in both plants and animals. Yeast extract spread is exceptionally rich in niacin, providing around 128 mg in every 100 grams. Other good sources include fish, chicken, eggs, dairy products and mushrooms. Niacin is also added to breakfast cereals and flour. Additionally, your body can synthesize niacin from the amino acid tryptophan. Scientists have estimated that 60 mg of tryptophan can be used to create 1 mg of niacin. Recommended Intake www.canestar.com www.nurseinfo.in www.BrainKart.com The table below shows the RDA or adequate intake for niacin. These values are the estimated amount of niacin that most people (97.5%) need to get from their diets every day. It also shows the tolerable upper intake limit (UL), which is the highest daily intake considered safe for most people. RDA UL (mg/day) (mg/day) Infants 0–6 months 2* - 7–12 months 4* - Children 1–3 years 6 10 4–8 years 8 15 9–13 years 12 20 Women 14+ years 14 30 Men 14+ years 16 30 Pregnancy 18 30–35 Lactation 17 30–35 *Adequate intake www.canestar.com www.nurseinfo.in www.BrainKart.com Deficiency Niacin deficiency, known as pellagra, is uncommon in developed countries. The main symptoms of pellagra include inflamed skin, mouth sores, diarrhea, insomnia and dementia. Like all deficiency diseases, it is fatal without treatment. Fortunately, you can easily get all the niacin you need from a varied diet. Deficiency is much more common in developing countries where people commonly follow diets that lack diversity. Cereal grains are especially low in available niacin, since most of it is bound to fiber in the form of niacytin. However, your body can synthesize it from the amino acid tryptophan. As a result, severe niacin deficiency can often be avoided on a high-protein diet. Side Effects and Toxicity Naturally occurring niacin from food does not appear to have any adverse effects. However, high supplemental doses of niacin may cause niacin flush, nausea, vomiting, stomach irritation and liver damage. Niacin flush is a side effect of immediate-release nicotinic acid supplements. It is characterized by a flush in the face, neck, arms and chest. www.canestar.com www.nurseinfo.in www.BrainKart.com Liver damage is associated with the long-term use of very high doses (3–9 grams per day)