Micronutrients and their roles in maintenance of health 2024 Student Version PDF

GEN N105BF Food for Shape 營養 ∙ 養型 School of Nursing and Health Studies Micronutrients and their roles in maintenance of health Prepared by Dr. Queenie Law Today’s lecture Describe different types, functions and food sources of micronutrients Understanding Vitamins Vitamins are chemically defined...

GEN N105BF Food for Shape 營養 ∙ 養型 School of Nursing and Health Studies Micronutrients and their roles in maintenance of health Prepared by Dr. Queenie Law Today’s lecture Describe different types, functions and food sources of micronutrients Understanding Vitamins Vitamins are chemically defined (Dudek, 2014, p. 93) Understanding Vitamins (cont’d) Vitamins are susceptible to destruction High temperatures Thiamin is heat sensitive and is easily destroyed by high temperatures and long cooking times e.g. (Dudek, 2014, p. 94) Understanding Vitamins (cont’d) Vitamins are susceptible to destruction Light e.g. Riboflavin is resistant to heat, acid, and oxidation but is quickly destroyed by light Heat, air and alkalis e.g. Vitamin C is destroyed by heat, air, and alkalis (Dudek, 2014, p. 94) Understanding Vitamins (cont’d) Vitamins may exist in more than one form vitamin A exists as retinol (important for reproduction) retinal (needed for vision) retinoic acid (acts as a hormone to regulate growth). http://dxline.info/diseases/beta-carotene (Dudek, 2014, p. 93) Understanding Vitamins (cont’d) Vitamins may exist in more than one form Some vitamins have provitamins, an inactive form found in food that the body converts to the active form. Beta-carotene (provitamin of vitamin A) http://dxline.info/diseases/beta-carotene (Dudek, 2014, p. 93) Understanding Vitamins (cont’d) Vitamins are Essential Body cannot make them except vitamin A, vitamin D and niacin (available of the precursors) Microorganisms in the gastrointestinal tract (GI) synthesize vitamin K and vitamin B12 Some Vitamins are Coenzymes (Dudek, 2014, p. 95) Understanding Vitamins (cont’d) Some Vitamins are Antioxidants e.g. vitamin C is added to frozen fish to help prevent rancidity e.g. beta-carotene adds color to margarine (Dudek, 2014, p. 95) Understanding Vitamins (cont’d) Vitamins are Drugs e.g. mega dose of niacin are used to lower cholesterol e.g. Tretinoin is used as a topical treatment for acne vulgaris http://lifepharma.biz/product/retino-a-creamtretinoin-0-05ww/ https://www.yourdiscountchemist. com.au/nicotinic-acid-250mg100-tablets.html (Dudek, 2014, p. 95) Group Characteristics of Fat-Soluble and Water-Soluble Vitamins (Dudek, 2014, p. 97) http://whatisvitamin.blogspot.com/2013/02/thedifference-between-fat-and-water.html Vitamin A Roles in normal vision, reproduction, growth and immune system functioning Beta-carotene is a major antioxidant in the body (Dudek, 2014, p. 99) Vitamin A The body can store up to a year supply of vitamin A, 90% in liver Vitamin A is teratogenic, at high doses during pregnancy Food sources Retinol Liver, whole milk and fish BetaCarotene Pumpkin, sweet potatoes, carrots, peaches (Dudek, 2014, p. 99) Vitamin D Body has the potential to make all the vitamin D it needs if exposure to sunlight is optimal and liver and kidney functions are normal. The primary function of vitamin D is to maintain normal blood concentrations of calcium and phosphorus Food sources Vitamin D Liver, fatty fish and egg yolks (Dudek, 2014, p. 100) Vitamin D Older peoples are at risk for vitamin D deficiency because of various risk factors including Inadequate intake Limited sun exposure Reduced skin thickness Impaired GI absorption and Impaired activation by the liver and kidneys (Dudek, 2014, p. 100) Vitamin D (cont’d) http://hipo-health.blogspot.com/2010/08/benefits-of-vitamin-d-foryour-body.html Vitamin E functions as the primary fat-soluble antioxidant in the body, protecting PUFAs and other lipid molecules, such as LDL cholesterol, from oxidative damage Food sources Vitamin E Wheat germ oil, walnut oil, sunflower oil (Dudek, 2014, p. 101) Vitamin K Naturally in two forms phylloquinone (found in plants) menaquinones (synthesized in the intestinal tract by bacteria) A coenzyme synthesis of prothrombin proteins needed for normal blood clotting (Dudek, 2014, p. 102) Vitamin K (cont’d) Vitamin K deficiency (hypoprothrombinemia) characterized by an increase in prothrombin time Food sources Vitamin K Spinach, broccoli, brussels sprouts (Dudek, 2014, p. 102) Vitamin K (cont’d) Use of certain medications that interfere with vitamin K metabolism or synthesis Anticoagulants, such as warfarin (Coumadin) interfere with hepatic synthesis of vitamin K–dependent clotting factors should try to maintain a consistent intake Antibiotics kill the intestinal bacteria that synthesize vitamin K (Dudek, 2014, p. 103) Thiamin (vitamin B1) Coenzyme in the metabolism of carbohydrates and branched chain amino acids Thiamin deficiency is usually seen only in alcoholics with limited food consumption (Dudek, 2014, p. 106) Vitamin B6 Synthesis, catabolism and transport of amino acids Involved in the formation of heme for hemoglobin Helps to regulate blood glucose levels (release of stored glucose from glycogen) Stored extensively in muscle tissue (Dudek, 2014, p. 106) Folate Major function is in synthesis of DNA With the aid of vitamin B12, folate is vital for synthesis of new cells and transmission of inherited characteristics Involved in homocysteine metabolism (Dudek, 2014, p. 106) Folate Healthy GI tract: maintain folate balance When GI integrity is impaired, failure to reabsorb folate quickly leads to folate deficiency Food sources Folate Liver, okra, spinach, asparagus, dried peas and beans, seeds, orange juice; breads, cereals, and other grains are fortified with folic acid (Dudek, 2014, p. 106) Vitamin B12 It activates folate, is involved in DNA synthesis and maturation of red blood cells Vitamin B12 requires an intrinsic factor, a glycoprotein secreted in the stomach, to be absorbed from the terminal ileum. (Dudek, 2014, p. 106) Vitamin B12 Deficiencies of vitamin B12 are rare Are likely to occur only in strict vegans A vegan (strict vegetarian) does not consume meat, dairy products, eggs, honey, or any product derived from an animal. Food sources Vitamin B12 Animal products: meat, fish, poultry, shellfish, milk, dairy products, eggs Some fortified foods (Dudek, 2014, p. 106) Vitamin B12 (cont’d) lack of intrinsic factor, which prevents absorption of vitamin B12 regardless of intake; this condition is known as pernicious anemia People with pernicious anemia, which can occur secondary to gastric surgery or gastric cancer, require parenteral injections of vitamin B12. (Dudek, 2014, p. 106) Vitamin B12 (cont’d) B12 deficiency arises from inadequate gastric acid secretion, which prevents protein-bound vitamin B12 in foods from being feed. (Dudek, 2014, p. 106) Vitamin B12 (cont’d) Other factors that increase the risk of B12 deficiency include gastric resection use of medications that suppress gastric acid secretion gastric infection with Helicobacter pylori (Dudek, 2014, p. 106) Vitamin C Prevents scurvy by promoting the formation of collagen Water-soluble antioxidant that protects vitamin A, vitamin E, PUFA and iron from destruction Food sources Vitamin C Citrus fruits and juices, red and green peppers, broccoli, cauliflower, Brussels sprouts, cantaloupe, kiwifruit, mustard greens, strawberries, tomatoes (Dudek, 2014, p. 106) Minerals (Dudek, 2014, p. 130) (Dudek, 2014, p. 130) Vitamin B12 It activates folate, is involved in DNA synthesis and maturation of red blood cells Vitamin B12 requires an intrinsic factor, a glycoprotein secreted in the stomach, to be absorbed from the terminal ileum. (Dudek, 2014, p. 106) Vitamin B12 Deficiencies of vitamin B12 are rare Are likely to occur only in strict vegans A vegan (strict vegetarian) does not consume meat, dairy products, eggs, honey, or any product derived from an animal. Food sources Vitamin B12 Animal products: meat, fish, poultry, shellfish, milk, dairy products, eggs Some fortified foods (Dudek, 2014, p. 106) Vitamin B12 (cont’d) lack of intrinsic factor, which prevents absorption of vitamin B12 regardless of intake; this condition is known as pernicious anemia People with pernicious anemia, which can occur secondary to gastric surgery or gastric cancer, require parenteral injections of vitamin B12. (Dudek, 2014, p. 106) Vitamin B12 (cont’d) B12 deficiency arises from inadequate gastric acid secretion, which prevents protein-bound vitamin B12 in foods from being feed. (Dudek, 2014, p. 106) Vitamin B12 (cont’d) Other factors that increase the risk of B12 deficiency include gastric resection use of medications that suppress gastric acid secretion gastric infection with Helicobacter pylori (Dudek, 2014, p. 106) Vitamin C Prevents scurvy by promoting the formation of collagen Water-soluble antioxidant that protects vitamin A, vitamin E, PUFA and iron from destruction Food sources Vitamin C Citrus fruits and juices, red and green peppers, broccoli, cauliflower, Brussels sprouts, cantaloupe, kiwifruit, mustard greens, strawberries, tomatoes (Dudek, 2014, p. 106) Minerals (Dudek, 2014, p. 130) (Dudek, 2014, p. 130) Sodium It is a major electrolyte in the body It helps in maintaining extracellular fluid balance Excess sodium intake has been linked to high blood pressure Not more than 2,000mg per day Food sources Sodium Salt, soy sauce, processed foods (Centre for Food Safety, 2015) Potassium Works to main fluid balance, acid-base balance, transmit nerve impulses, catalyze metabolic reactions etc Adequate potassium intake lowers blood pressure and reduces risk of stroke Food sources Potassium Potatoes, fruit, vegetables, milk and nuts (Centre for Food Safety, 2015) Potassium When potassium excretion is impaired e.g. end stage kidney disease, severe heart failure, high potassium intake can lead to hyperkalemia and life-threatening cardiac arrhythmias Reference values: 2.7g to 3.1 g per day (Centre for Food Safety, 2015) Calcium For providing rigidity to the skeleton Roles in nerve transmission, muscle contraction and blood clotting Not less than 1000mg per day for adults Food sources Calcium Milk and milk products, green leafy vegetables, fish with edible bones, soy bean and bean curd (Centre for Food Safety, 2015) Iron For metabolic functions such as oxygen transport and storage Not less than 24.5mg per day for women and not less than 11.4mg per day for men Insufficient intake may result in iron deficiency anemia Food sources Iron Liver, red meats, dried peas, beans and fortified cereals (Centre for Food Safety, 2015) One in eight Hong Kong blood donors rejected due to low iron levels, Red Cross says https://www.scmp.com/news/hong-kong/healthenvironment/article/2074817/one-eight-hong-kongblood-donors-rejected-due-low https://youtu.be/_GjYifHwpd8 https://www5.ha.org.hk/rcbts/eligibility?lang=en References Centre for Food Safety. (2015). Nutrients Definition and Functions. Retrieved from http://www.cfs.gov.hk/english/nutrient/nutrient.php Dudek, S. G. (2014). Nutrition Essentials for Nursing Practice (7th ed.). New York: Lippincott Williams & Wilkins.