Nutrition and Diet (cont.)
IN THIS ARTICLE
Vitamins are needed in small quantities to perform invaluable functions. They are required for normal function, growth, and maintenance of body tissues. Without a sufficient quantity of any vitamin, a deficiency will occur with a subsequent decline in health. Fortunately, a balanced diet is often sufficient enough to meet your needs.
Vitamins fall into two classes: fat-soluble and water-soluble. Their solubility will determine how the vitamin is absorbed and transported by the bloodstream, whether or not it can be stored in the body, and how easily it can be lost from the body. Requirements for each of the vitamins are based on age, gender, pregnancy, and lactation. You can find them at http://www.iom.edu/Object.File/Master/7/296/
The fat-soluble vitamins are A, D, E, and K. Adequate absorption of these vitamins is dependent on efficient fat intake and absorption. Except for vitamin K, fat-soluble vitamins are not easily excreted from the body, so they can be toxic at excessive levels. The only way to reach toxic levels would be through taking supplements, not through your diet. This is another case when balance is the key, and excessive amounts can cause harm.
Vitamin A is abundant in our food supply, so there is little risk of a deficiency. It is needed for regulation of the immune system, vision, reproduction, bone growth, cell division, and cell differentiation. A deficiency will result in night blindness and a decreased immune system, resulting in a decrease in the ability to fight infections. This can occur from an inadequate diet, chronic diarrhea, and an excess intake of alcohol. Dietary sources of vitamin A include
Vitamin D is supplied by our diet and sunlight. Exposure to ultraviolet (UV) rays from the sun can trigger the production of vitamin D in our body. The amount of sun needed will depend on your skin color, age, the time of the day, season, and geographic location. Experts have recommended that you expose your hands, face, and arms two to three times a week for about 10 to 15 minutes without sunscreen.
Vitamin D is needed for healthy bones by maintaining normal blood levels of calcium and phosphorus and for maintenance of a healthy immune system. A deficiency in children can result in rickets, and a deficiency in adults can cause osteomalacia. An inadequate diet, limited exposure to sunlight, and malabsorption can cause the deficiency. Dietary sources of vitamin D are
Vitamin E has been shown to have a wide array of health benefits, including prevention of stroke, diabetes, cancer, heart disease, arthritis, cataracts and improved immune function. With all of the functions that vitamin E has, a deficiency of it can result in numerous health problems. Fortunately, vitamin E deficiencies are rare in this country. Dietary sources of vitamin E are
Without vitamin K, your blood would not clot, so it is essential for everyone. Vitamin K is also needed for bone proteins. Some vitamin K can be made in the intestines. When people take antibiotics that kill the beneficial and harmful bacteria in the intestines, it puts them at risk for a vitamin K deficiency. Dietary sources of vitamin K include
Medically Reviewed by a Doctor on 12/23/2015
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