Vitamins PDF

VITAMINS  Collection of different molecules They don´t have common chemical characteristics Fats, carbohydrates, proteins have a common chemical characteristic CLASSIFICATION: Based on solubility in water or organic solvents Water- soluble (9-B-vitamins and vit. C)- dissolve easily i...

VITAMINS  Collection of different molecules They don´t have common chemical characteristics Fats, carbohydrates, proteins have a common chemical characteristic CLASSIFICATION: Based on solubility in water or organic solvents Water- soluble (9-B-vitamins and vit. C)- dissolve easily in water, and in general, are readily excreted from the body (kidney). Absorbed easily in the blood (hydrophilic fluid ) The degree of urinary output is a strong predictor of vitamin consumption. As they are not readily stored, consistent daily intake is important. If you think vit C is going to get rid of your common cold and you take 5 gr of Vit C per day during 3-4 days ,it´s not going to cause you any harm.You will be two days lossing vit C in your urine Fat -soluble Soluble in organic solvents Vitamins are absorbed through the intestinal tract with the help of lipids They are more likely to accumulate in the body, and to lead to hypervitaminosis than are water-soluble vitamins. Excess accumulate in fatty tissues. Can be toxic. Transported like fats: absorbed in the intestine and go to the lymphatic system. Stored like fats in fat cells and fatty places in the body. If you loose fat they can interfere in your metabolism because they have no place to go. Mother overdosing infants¡¡¡ VITAMIN C (ASCORBIC ACID) Functions Protect cells from damage caused by free radicals because it can react with them and convert them to less damaging species. Affects iron absorption ,through reduction from the ferric to ferrous form, and binding of the iron. Contributes to collagen synthesis James Lind is remembered as the man who helped to conquer a killer disease. His reported experiment on board a naval ship in 1747 showed that oranges and lemons were a cure for scurvy. 6  Deficiency Scurvy-skin changes reflects effects on collagen synthesis Hemorrhage of the gum capillaries and poor wound healing Sources 10 Vitamin B12 Important role in metabolism Deficiency: – Megaloblastic anemia (pernicious anemia) – Spinal cord degeneration and peripheral neuropathy (it´s essential for making fatty myelin sheath that covers nerve fibres) Myelin is a fatty coating that covers neuron axons in the Central nervous system, increasing the speed and efficiency of conductivity Damage to the myelin sheath eventually leads to visual, motor, sensory, coordination, and cognitive dysfunctions.  Deficiency Poor absorption because a failure to secrete intrisic factor (IF) into the stomach. Pernicious anaemia is most common among the elderly. IF is a protein made in the stomach that helps absorption of B12 Food sources Animal sources Rich sources include liver, fish and meat Folate (B9) Synthesis of purines and pyrimidines for nucleic acid synthesis. Deficiency: megaloblastic anaemia. Inmature red blood cells due to a failure in the normal process of maduration in the bone marrow. Increases the risk of neural tube deffects in their offspring. The neural tube, which runs from the brain to the lower end of the spinal cord , normally closes in embryonic development in the third and fourth weeks after fertilization. A failure of the process leads to a range of severe fetal malformations collectively known as neural tube defects. Food Sources Green leafy vegetables (foliage) are rich sources of folate and provide the basis for its name. Citrus fruit juices, legumes, and fortified foods are also excellent sources of folate Deficiency Vitamin D It can be synthesized in the skin. Cholecalciferol is both the usual dietary form and the form of vitamin D synthesized in the skin by UV irradiation of the precursor, 7-dehydrocholesterol. cholecalciferol 25,hydroxyl- cholecalciferol 25,dihydroxycholecalciferol Function The main physiological function of vitamin D is to maintain calcium balance. It maintains the plasma concentration of calcium by increasing intestinal absorption of calcium, reducing excretion by increasing reabsorption in the renal tubule , and mobilizing the mineral from bone.  DEFICIENCY Rickets: Results from a failure of the mineralization of newly formed bone, which as the child grows, leads to bow legs or knock knees, as well as deformity of pelvis. Osteomalacia: is the defective remineralization of bone during normal bone turnover in adults, leading to progressive demineralization and skeletal deformities. Osteoporosis: is a loss of bone mineral and matrix with age. Osteoporosis 22 Rickets Osteomalacia (greek) Osteo-Bone Malacia-Softness 24 Food sources Fish, fish liver and fish oil are main natural animal sources of vitamin D3 – cholecalciferol. Egg yolk, beef liver and cheese also contain some vitamin D. In some countries, vitamin D is added to milk. VITAMIN E The term vitamin E describes a family of eight antioxidants. Alpha-tocopherol is the only form of vitamin E that is actively maintained in the human body; therefore, it is the form of vitamin E found in the largest quantities in blood and tissues. It helps to prevent cancer and cataracts formation Antioxidant important for preventing oxidation of lipid in membranes and lipoproteins Inhibits platelet aggregation and vascular smooth muscle proliferation. DEFICIENCY Deficiency is rare. Only in patients with severe malabsorption. Sources: vegetable oils, oily fish, nuts, seeds,some vegetables. Vitamin K The "K" is derived from the German word "koagulation.“ Coagulation refers to the process of blood clot formation. Vitamin K is essential for the functioning of several proteins involved in blood clotting. It is usual to give all new-born infants prophylactic vitamin K, either orally or by intramuscular injection. If a patient is taking anticoagulants should avoid foods containing vitamin K Sources Bacteria that normally colonize the large intestine synthesize menaquinones (vitamin K2), which are an active form of vitamin K. Green leafy vegetables and some vegetable oils (soybean, canola, and olive) are major contributors of dietary vitamin K Food Serving Vitamin K (mcg) Olive oil 1 Tablespoon 8.1 Soybean oil 1 Tablespoon 25.0 Canola oil 1 Tablespoon 16.6 Mayonnaise 1 Tablespoon 3.7 Broccoli, cooked 1 cup (chopped) 220 Kale, raw 1 cup (chopped) 547 Spinach, raw 1 cup 145 Leaf lettuce 1 cup (shredded) 62.5 (green), raw Swiss chard, raw 1 cup 299 Watercress, raw 1 cup (chopped) 85 Parsley, raw 1/4 cup 246  Deficiency Impaired blood clotting: nosebleeds, bleeding gums, blood in the urine, blood in the stool, or extremely heavy menstrual bleeding. In infants, vitamin K deficiency may result in life-threatening bleeding within the skull (intracranial hemorrhage) Vitamin A It is a generic term for a large number of related compounds: Pre-formed vitamin A, which include retinol, retinaldehyde and retinoic acid. A variety of carotenoids which can be converted to retinal. The most important of the provitamin A carotenoids are α- and β-carotene , and cryptoxanthin. VITAMIN A. FUNCTIONS Carotenoids have antioxidant activity. They have protective effects against certain cancers and cardiovascular disease. It is important for vision 33  VITAMIN A. DEFICIENCY In children in developing nations is the leading preventable cause of blindness.The earliest evidence is impaired dark adaptation or night blindness. Mild vitamin A deficiency may result in changes in the conjunctiva (corner of the eye) called Bitot's spots. Severe or prolonged vitamin A deficiency causes a condition called xeropthalmia (dry eye), characterized by changes in the cells of the cornea (clear covering of the eye) that ultimately result in corneal ulcers, scarring, and blindness. 35 DEFICIENCY Can be considered a nutritionally acquired immunodeficiency disease.Even children who are only mildly deficient in vitamin A have a higher incidence of respiratory disease and diarrhea as well as a higher rate of mortality from infectious disease. Sources Liver Full-fat dairy products Fortified margarine RETINOL Oily fish Kidneys Dark green Yellow fruits and CAROTENOIDS Red vegetables Orange  Vitamin A, Food Serving RAE Vitamin A, IU Retinol, mcg Retinol, IU Cod liver oil 1 teaspoon 1,350 mcg 4,500 IU 1,350 mcg 4,500 IU Fortified breakfast 1 serving 150-230 mcg 500-767 IU 150-230 mcg 500-767 IU cereals Egg 1 large 91 mcg 303 IU 89 mcg 296 IU Butter 1 tablespoon 97 mcg 323 IU 95 mcg 317 IU Whole milk 1 cup (8 fl oz.) 68 mcg 227 IU 68 mcg 227 IU 2% fat milk (vitamin A 1 cup (8 fl oz) 134 mcg 447 IU 134 mcg 447 IU added) Nonfat milk (vitamin A 1 cup (8 fl oz.) 149 mcg 497 IU 149 mcg 497 IU added) 1/2 cup, Sweet potato, canned 555 mcg 1,848 IU 0 0 mashed Sweet potato, baked 1/2 cup 961 mcg 3,203 IU 0 0 Pumpkin, canned 1/2 cup 953 mcg 3,177 IU 0 0 1/2 cup, Carrot (raw) 538 mcg 1,793 IU 0 0 chopped 1/2 medium Cantaloupe 467 mcg 1,555 IU 0 0 melon Mango 1 fruit 79 mcg 263 IU 0 0 1/2 cup, Spinach 472 mcg 1,572 IU 0 0 cooked B1 -Thiamin deficiency Beriberi, was described in Chinese literature as early as 2600 B.C. The term beriberi is derived from the Sinhalese (Sri Lanka) word meaning “extreme weakness". Thiamin deficiency affects the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems Beriberi has been subdivided into dry, wet, cerebral, or gastrointestinal, depending on the systems affected 39  Dry beriberi The main feature of dry (paralytic or nervous) beriberi is peripheral neuropathy. Early in the course of the neuropathy, "burning feet syndrome" may occur. Other symptoms include abnormal (exaggerated) reflexes, as well as diminished sensation and weakness in the legs and arms. Wet beriberi In addition to neurologic symptoms, is characterized by cardiovascular manifestations which include rapid heart rate, enlargement of the heart, severe swelling (edema), difficulty breathing, and ultimately, congestive heart failure Cerebral beriberi may lead to Wernicke's encephalopathy and Korsakoff's psychosis, especially in people who abuse alcohol. 40 Unpolished brown rice (right) is the whole grain of rice with just the outer cover (the husk) removed. Milled rice (centre) has the germ and bran layer removed. Finally, polished white rice (left) is polished to a smooth finish, but what’s left is mostly starch 41 42