Lecture 23 11/19/08

NUTR 300 11/19/08 Nutrition for Today Nutrition and Physical Activity I Learning objectives: Name the B vitamins required for energy production and state fuels they help to metabolize Name the deficiency diseases and two symptoms associated with deficiencies of thiamin and niacin Name what nicotinic acid prescriptions are used to treat and what the adverse side effects are Explain why poor dietary intake of the B vitamins decreases one?s ability to do physical activity and work Name two good food sources of each of the B vitamins discussed Energy production from macronutrients McArdle, Katch & Katch. Sports & Exercise Nutrition 2e. 2005 Glycolysis Lipolysis and ?-oxidation Amino acid catabolism and gluconeogenesis TCA cycle and electron transport Vitamins act as co-enzymes Required for proper enzyme activity Thiamin Required for energy production from carbohydrates, fats and proteins as a coenzyme for steps in the TCA cycle Food sources Whole or enriched grains, meats (especially pork products), nuts and seeds Too much thiamin No adverse effects reported from high intakes of food or supplemental thiamin Too little thiamin Beriberi - weakness and muscle wasting Wernicke-Korsakoff syndrome ? characteristic thiamin deficiency in alcoholics ? tremor, confusion, memory deficits Riboflavin Required for energy production from carbohydrates, fats and proteins as a coenzyme for steps in the TCA cycle and electron transport chain Food sources Meats, eggs, milk and milk products, broccoli, spinach, fortified cereals Unstable to light (milk cartons) Too much riboflavin No adverse effects reported from high intakes of food or supplemental riboflavin Too little riboflavin Ariboflavinosis ? sore throat, swelling of mouth and tongue, cracked lips and corners of mouth Niacin Required for energy production from carbohydrates, fats and proteins as a coenzyme for steps in the TCA cycle and electron transport chain Food sources Meats, fish, poultry, whole grains, enriched grains, beans Too much niacin No adverse effects form high intake of niacin from foods Supplemental nicotinic acid in high doses ? flushing (burning, tingling, itchy sensation, reddening of face and arms), liver damage in very high doses Too little niacin Pellagra ? ?4 Ds? Diarrhea, Dermatitis, Dementia, Death Vitamin B6 (pyridoxine) Required for transamination reactions ? generation of carbon skeletons from amino acids for: Synthesis of non-essential amino acids Gluconeogenesis Glycogen breakdown Food sources Meat, fish, poultry, starchy vegetables and fortified cereals Too much B6 Supplemental B6 in high doses ? sensory neuropathy (weakness, numbness and tingling) Too little B6 Symptoms of B6 deficiency ? fatigue, anemia, depression, swelling of mouth and tongue, cracked lips and corners of mouth Biotin Also required for use of certain fatty acids and amino acids in energy production Food sources Egg yolk, soybeans, yeast, peanut butter, beans, nuts, whole grains Too much biotin No adverse effects form high intake of B6 from foods or supplements Too little biotin Rare. Symptoms ? hair loss (alopecia), dermatitis, depression, numbness and tingling Consumption of lots of egg whites (avidin = protein in egg whites that binds biotin) Pantothenic acid Required for energy production from carbohydrates, fats and proteins (acetyl CoA) Food sources Widely distributed (pan) - good sources ? meat, poultry, avocado, bran, broccoli, whole grains, legumes, eggs, mushrooms, and more Too much pantothenic acid No adverse effects of consuming high doses of pantothenic acid from foods or supplements Too little pantothenic acid Extremely rare Vocabulary: Coenzyme Thiamin Beriberi Wenicke-Korsakoff syndrome Riboflavin Ariboflavinosis Niacin Nicotinic acid Nicotinamide Biotin Avidin Pantothenic acid Nutrient Forms of the vitamin and active form Foods Enable us to derive energy from? Deficiency (all result in weakness and fatigue) Toxicity Thiamin thiamin; TPP meats, grains, nuts, seeds, beans carbohydrates, fats, proteins beriberi - muscle wasting weakness, heart failure none Riboflavin Riboflavin; FMN, FAD milk, meats, eggs carbohydrates, fats, proteins swollen tongue, cracked lips none Niacin Nicotinic acid, nicotinamide; NAD, NADP meats, grains, nuts, seeds, beans carbohydrates, fats, proteins pellagra - dermatitis, diarrhea, dementia, death high dose nicotinic acid - flushing, burning sensation; potential liver toxicity Vitamin B6 Pyridoxal, pyridoxine, pyridoxamine; PLP meats, grains, nuts, seeds proteins swollen tongue, cracked lips high dose B6 - peripheral neuropathy Biotin biotin eggs, grains, nuts, seeds certain fatty acids and certain amino acids facial dermatitis, hair loss (alopecia) none pantothenic acid patothenic acid; CoA meats, grains, nuts, seeds carbohydrates, fats, proteins extremely rare - "burning feet" none E. Kirk PhD, RD PAGE 3