Vitamins

, including retinol and "provitamin caretenoids," is found in liver, butter, whole milk, cheese and egg yolks and in carrots, leafy greens, sweet potatoes, pumpkins, cantaloupes and so on (provitamin caretenoids). Vitamin A is extremely important formation and maintenance of skin and mucous membranes, in visual functions and in bone and tooth development. A deficiency of Vitamin A can cause impaired growth, nigh blindness, diarrhea and increased mortality in the worst cases. Experiments in giving large Vitamin A supplements for malnourished children have had mixed results; some reported a reduction in infant and child mortality, but a recent study of Sudanese children between 9 and 72 months found little difference in a test group that was given megadoses of A (200,000 units) and a placebo group that was given only small amounts of Vitamin E.
Vitamin D (calciferol) found mostly in fortified dairy products but also in fish oils egg yolks, is particularly important for hardening of bones and teeth, and aiding in the intestines absorption of calcium. Deficiencies of D can cause rickets in children and more rarely, oseomalacia in adults; overdoses are known to cause retarded growth, kidney damage and calcium deposits in the soft tissues. Vitamin E (Tocopherol) is found in vegetable oil, green leafy vegetables, wheat germ, egg yolk, butter and liver. It functions as an "antioxidant" for other vitamins, preventing C and A and other fatty acid proteins from being burnt up prematurely; in this way it helps prevent cell membrane damage. Most experts believe that Vitamin E deficiency can only occur in extreme causes of malnutrition, but this doesnt mean that supplements might not be useful. One recent study found that Vitamin E rich blood helped to preven