Food and nutrition.pdf

66 Nutrientssoya beans, nuts, apples, apricots and green vegetables. Vitamin Edeficiency may cause anemia, as a result of red blood cell destruction andneurological dysfunction, myopathies, and diminished erythrocyte lifespan. New clinical evidence from heavy drinkers suggests that alcoholmay increase oxidation of Alpha-Tocopherol. Increased demand has alsobeen observed in premature infants and patients with malabsorption.It is generally non toxic but some evidence suggests that large intakesmay cause increased levels of blood cholesterol and lipids. It can oxidizewithin a few months of being manufactured, so supplements should notbe stored for more than a few months. It is destroyed by heat, freezing,food processing, chlorine and iron.Vitamin K (Menadione)Vitamin K is a fat soluble vitamin usually formed in the body byintestinal bacteria but also available from some plant and animal sources.The RDA for adult males is 80 micrograms.Its primary function is to control the rate of blood clotting and preventinternal bleeding.The best natural sources are all leafy green vegetables, cauliflower,brussel sprouts, broccoli, soybean oil, kelp, cereal grain products, fruitsand yoghurt.Vitamin K deficiency has been reported in patients treated withantibiotics and placed on poor diets after surgery. A deficiency can causebleeding disorders. Doctors sometimes give women vitamin K beforechildbirth to prevent bleeding in the newborn baby. Babies do not haveenough intestinal bacteria to produce adequate amounts of the vitaminuntil they are about 2 weeks old.No toxicity symptoms have been recorded from natural forms butsupplementation of synthetic vitamin K exceeding 500 mcg is notrecommended as it can cause anemia and kernicterus, a conditioncharacterized by jaundice.BiotinBiotin is a member of the B complex family and is water soluble. TheRDA for adults is 100 micrograms.It is essential for the metabolism of fats and the synthesis of ascorbicacid. It maintains a healthy skin and helps prevent baldness and hair fromturning grey.The best natural sources are soya beans, brown rice, nuts, fruit,brewer's yeast and milk. It can be synthesized by intestinal bacteria.It is not toxic. Avidin, a substance found in egg white prevents biotinabsorption. Sulfur drugs, food processing and alcohol destroy biotin.