Part 3 Vitamins and Minerals 10 25 2010 Vitamins Organic Compounds o Contain carbon o Many different structures from simple to complex Non caloric Essential o Lack of vitamin leads to deficiency o Cannot be synthesized in body with exceptions o Ex Scurvy and vitamin C Needed in small amounts o Milligrams mg 10 3 grams o Vitamin C 60 mg o Micrograms g 10 6 grams o Vitamin B12 2 g Limited Synthesis of two Vitamins Vitamin D o Synthesized in the skin o Require sunlight and 7 dehydrocholesterol Niacin o Requires tryptophan o Depends on adequate protein status Classification of Vitamins Fat soluble o Vitamins A D E and K o Absorbed like dietary fat via lymph requires bile o Can be stored in body fat and in liver o Generally have greater body stores than water soluble vitamins Water Soluble o High likelihood of toxicity A D most toxic o Thiamin Riboflavin Niacin Pantothenic Acid Vitamin B6 Folate Vitamin B12 Biotin and Vitamin C o Absorbed into the bloodstream o Usually excreted in urine o Generally have lower body stores than fat soluble vitamins o Low likelihood of toxicity Minerals Nutrients Inorganic o Do not contain carbon o May contain an electrical charge Noncaloric Essential o Lack of mineral for prolonged time leads to deficiency o Ex Iron deficiency anemia Stored well in body can be toxic at high levels Development and Detection of a Nutrient Deficiency Primary deficiency caused by inadequate intake or secondary deficiency caused by problem inside the body Diet history Medical history Declining nutrient stores Laboratory tests Abnormal functioning inside the body Laboratory tests Physical signs and symptoms Physical examination and anthropometric measures Nutrient Deficiency and Toxicity The nutrient requirement is on a personal basis o Those growing or developing Infants children and teens Pregnant and lactating women o Those with physiological changes Elderly HIV AIDS patients Alcoholics Food versus Supplements Vitamins and minerals absorbed best from food bioavailability May not be used the same way by the body moderators in foods Little risk of toxicity from food Other beneficial compounds in food fiber phytochemicals Potential dangers of dietary supplements lack of regulation The amount of a nutrient in a food that is actually available for Bioavailability human use o Not just the amount of a nutrient in a food o The amount that is absorbed and used o Sometimes nutrients are more available in fortified forms Ex Folate Factors Affecting Bioavailability Non nutritive components of food o Fiber Zinc Calcium Copper o Phytate Zinc o Oxalic acid Calcium Chemical form of the mineral o Elemental versus complexed Ex Heme iron versus non heme iron Mineral mineral interactions o Zinc and iron o Copper and zinc Vitamin mineral interaction o Vitamin C and non heme iron absorption Food Processing and Nutrient Content of Foods Some vitamins minerals break down when exposed to oxygen so the fresher the better Cooking method can impact the nutrient content of foods Generally cooking for shorter times in little water will help to maintain nutrient content steam microwave Water soluble less stable than fat soluble Functions of Vitamin A Gene expression Immune defenses Vision blindness Maintenance of body linings and skin cell differentiation Growth of bones and of the body growth failure Normal development of cells Reproduction birth defects Vitamin A and Vision Part of rhodopsin a pigment within the cells of the retina When light falls on the eye vitamin A splits from rhodopsin initiating a signal that conveys the sensation of sight to the brain Vitamin A deficiency leads to night blindness Needed by epithelial tissue including the protective linings of the eyes Lack of vitamin A makes eye more susceptible to drying and infection cell differentiation 500000 of the world s vitamin A deprived children become blind each year Functions of Vitamin D Regulates blood calcium and phosphorous levels thereby maintaining bone integrity osteomalacia rickets Stimulates maturation of cells including immune cells that defend against disease Acts on genes affecting how cells grow multiple and specialize cancer multiple sclerosis Functions of Vitamin E Tocopherol Antioxidant o Also Vitamin C beta carotene and other carotenoids zinc selenium and copper phytochemcials o A substance that prevents free radicals from causing damage to body structures such as cells membranes and DNA Free Radical Damage Free Radical o A molecule often oxygen with unpaired electrons that cause damage to body structures o Sources Endogenous immune system metabolism exogenous pollutants cigarette smoke Cell membranes and lipids causing cell lysis and impaired receptor Inactivation and degradation of proteins and enzymes Damage to DNA causing mutations and altered gene function Diseases Caused by Free Radicals function Heart Disease Cancer Aging Cataracts Free Radical Theory of Heart Disease Free radicals oxidize LDL cholesterol Oxidized LDL picked up by white blood cells now called foam cells Foam cells lodge in side of arteries beginning of plaques Sources of Vitamin K Vitamin K can be made by intestinal bacteria Newborns are given a dose of vitamin K at birth Functions of Vitamin K Blood clotting Component of bone proteins Functions of Vitamin C o Anticoagulants interfere with action of Vitamin K Assists enzymes involved in the formation and maintenance of collagen wound healing scurvy Acts as an antioxidant especially protecting the immune system cells from free radicals generated during their assault on invaders Curing the common cold The B Vitamins Thiamin beriberi Riboflavin Niacin pellagra Folate NTDs anemia Pantothenic acid B12 anemia B6 Biotin Tender Romance Never Fails with 6 or 12 Beautiful Pearls Sources of the B Vitamins Enriched grains o Thiamin niacin riboflavin folate o Thiamin Niacin peanuts folate pantothenic acid Legumes Vegetables o Niacin except corn folate Fruits o Folate Vitamin C Animal products o Thiamin riboflavin dairy vitamin B12 only pantothenic acid biotin eggs Vitamin B6 Functions of the B Vitamins Thiamin riboflavin niacin pantothenic acid and biotin are coenzymes in energy production pathways B12 and folate involved in cell division synthesize DNA B6 helps the body use amino acids to synthesize proteins role in synthesis of hemoglobin and neurotransmitters Nerve transmission dependent upon thiamin Folate and B12 Folate and B12 work together to allow synthesis of new blood cells Too much folate can
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