The fat-soluble vitamins A, D, E and K are found in many foods, do not easily get lost in cooking and digest better when accompanied by fat. They are needed in only small amounts, and the excess is stored in the liver and fat tissues, so healthy persons need not consume them in food every day. Those with a disease that affects fat absorption may develop deficiencies of these vitamins. Toxic levels can build up with supplement megadoses.
Vitamin A
Vitamin A helps the eyes see clearly and adjust to light and keeps mucous membranes moist to resist infections. Excessive vitamin A can cause birth defects. Liver, whole or fortified milk and milk products contain vitamin A. Leafy green vegetables such as spinach, broccoli and brussels sprouts as well as yellow and orange fruits and vegetables such as cantaloupe, carrots, sweet potatoes and squash contain beta-carotene, which converts to vitamin A in the body.
Vitamin E
An antioxidant and defender against free-radical damage, vitamin E may also guard against cancer and heart disease. Widespread in foods, especially vegetable oils and products containing oils such as salad dressings and margarine, vitamin E is easily destroyed by heat, so choose fresh or lightly processed sources such as seeds and nuts and leafy green vegetables. Other good sources include whole grains, liver, egg yolks and wheat germ.
Vitamin D
The fact that vitamin D is manufactured by one part of the body and causes another part to respond makes it technically a hormone rather than a vitamin. Vitamin D maintains blood concentrations of calcium and phosphorus for bone growth. According to the USDA Cooperative Extension Service, vitamin D in excessive amounts, such as high-dosage supplements, causes hardening of arteries and organs. Food sources include fortified milk and margarine, cereals, beef, egg yolks, liver and fatty fish such as salmon and sardines.
Vitamin K
The action of vitamin K in blood clotting can make the difference between life and death. Bacteria in the gastrointestinal tract make vitamin K that the body can absorb and use. Food sources include milk, eggs, liver, leafy green vegetables, cabbage, brussels sprouts, collards, spinach and broccoli. Since bacteria make about half of the vitamin K for most people, deficiency is more likely in newborns and in people taking antibiotics or anticoagulant drugs, according to Eleanor Whitney and Sharon Rolfes in the textbook "Understanding Nutrition."
References
- USDA: Oklahoma Cooperative Extension Service: Vitamins and the Body
- "Understanding Nutrition, Ninth Edition"; Eleanor Noss Whitney and Sharon Rady Rolfes; 2002
- "Krause's Food, Nutrition, & Diet Therapy, 10th Edition"; Mahan and Escott-Stump; 2000.
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