NUTR 202 1nd Edition Lecture 14 Ch 7 Vitamins cont Vitamin E Alpha tocopherol is most active form in body Functions POWERFUL ANTIOXIDANT protects lipids throughout the body Protects cell membranes Red blood cells brain nerve cells lungs May prevents oxidation of LDL cholesterol In large dose reduces blood clotting Daily needs Adults need 15 mg of alpha tocopherol equivalents Too much or too little No known risk of excess vitamin E from natural food sources Over consumption from supplements and fortified foods Hemorrhage Upper limit is 1 000 mg day Deficiency rare Nerve problems muscle weakness and free radical damage to cell membranes Vitamin K Two forms of vitamin K These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Menaquinone Phylloquinone Important to bone health Blood clotting Involved in synthesizing four blood clotting factors opposite of vitamin E No known problems of consuming too much vitamin K from foods or supplements Found in green plants Functions Synthesized by intestinal bacteria No UL People taking certain anticoagulant medications such as warfarin Coumadin Need to keep vitamin K intake consistent Changes in intake can increase or decrease drug effectiveness Severe vitamin K deficiency May affect blood clotting but this is extremely rare Most not stored in the body in large amounts B vitamins Coenzymes for energy metabolism from macronutrients Vitamin C Antioxidant Connective tissue Choline Vitamin B complex Thiamin First B vitamin discovered Deficiency condition in Asia related to diet change from brown rice to polished rice Functions Coenzyme needed for breakdown of glucose to provide energy Important for nerve function because Glucose is nerve cell energy source Needed for synthesis of neurotransmitters chemical signals from neurons Needed for metabolism of other sugars certain amino acids and synthesis of ribose in RNA Too much or too little No known toxicity no UL set Deficiencies BERIBERI Symptoms include fatigue weakness from not metab glucose Also depression poor coordination paralysis Who is at risk of Beriberi Affects population of poor countries with an inadequate food supply nonenriched refined grains Riboflavin Forms two active coenzymes in reactions that Produce ATP from FAT carbohydrates and protein Converts a number of vitamins to their active forms coenzyme Folate Niacin Vitamin B6 Vitamin K Destruction of vitamin B2 UV light Irradiation Too much or too little No UL set Deficiency symptoms not common Usually with other B vitamin deficiencies Deficiency first noted in tissues with rapid cell turnover Lining of mouth lips Symptoms injuries heal poorly cracking of lips and corners of mouth sensitivity to light eye burning tearing itching skin flaking around nose eyebrows earlobes Niacin Can be made from tryptophan protein Functions Coenzyme for energy metabolism Glucose and fat SYNTHESIS OF CHOLESTEROL Maintaining health of skin cells digestive system and NS Daily needs men 16 mg day women 14 mg day Toxicity from too much Not from food supplementation a risk Symptoms include flushing nausea tingling of extremities may be toxic to LIVER UL is 35 mg day Prescribed in high doses by physicians Decrease LDL cholesterol and triglycerides increase HDL Deficiency Pellagra the four D s Dermatitis Diarrhea Dementia Death Once common in South due to corn based diet Vitamin B6 Functions as coenzyme for over 100 enzymes in PROTEIN METABOLISM To create nonessential amino acids To create hemoglobin in red blood cells To create neurotransmitters Conversion of tryptophan to niacin To break down glycogen for glucose 3 forms pyridoxal pyridoxine pyridoxamine Active coenzyme pyridoxal phosphate Deficiency symptoms Poor growth skin lesions poor immune response numbness or tingling in extremities Because of its role with red blood cell synthesis Microcytic anemia smaller red blood cells with less hemoglobin Folate Folate Naturally occurring form in foods Folic acid Synthetic form of folate Fortified to foods and found in supplements Absorbed more easily than folate Functions Amino acids metabolism Coenzyme for DNA synthesis Particularly important for rapidly dividing cells Folate deficiency can lead to formation of abnormally large immature red blood cells present this is called MACROcytic anemia Inadequate intake of folate folic acid before and during pregnancy can result in Neural tube birth defects Examples Incomplete development of brain spinal cord and or spine can t complete cell division Spina bifida Incomplete development of brain skull scalp Anencephaly May reduce the risks of some cancers Colon pancreatic breast ovarian Vitamin B12 Also called cobalamine because it contains the element cobalt ONLY water soluble vitamin STORED in body in significant amounts Important for ATP production from certain fatty acids Amino acid and protein metabolism Homocysteine to methionine conversion Prevention of heart disease Myelin coating of nerve cells