What Are Vitamins and What Do They Do?
|If you've ever walked through the aisles of your local grocery or health food store, you may have wondered about the purpose and importance of various vitamins. Vitamins are organic compounds that help maintain normal body functions, such as reproduction, growth and cell repair. Vitamins work with other vitamins and other substances like enzymes to help your cells function correctly, and an adequate consumption of vitamins is necessary for your body to work well. Your body can't manufacture vitamins, so you need to obtain them from other sources.
Most of the vitamins you need come from the food you eat, except for vitamin D, which your body makes when exposed to sunlight, and K, which is made by the bacteria in your intestines. In addition to their presence in natural foods, vitamins can also be manufactured synthetically.
Some people who feel that they aren't getting enough vitamins in the foods they eat or who have a health condition such as pregnancy will take a synthetic vitamin to ensure adequate vitamin intake. Vitamin supplements may be available in tablet, caplet or liquid form. Although the Food and Drug Administration (FDA) regulates vitamin supplements, they do not have established standards for quality. However, the United States Pharmacopeia recently established standards for vitamin supplements, so look for supplements that say "USP" on the product label.
Nutritionists categorize vitamins by the materials that a vitamin will dissolve in. There are two categories: water-soluble and fat-soluble vitamins. Water-soluble vitamins, which include the B-complex group and vitamin C, travel through the bloodstream. Whatever water-soluble vitamins are not used by the body are eliminated in urine, which means you need a continuous supply of them in your food.
Fat-soluble vitamins—vitamins A, D, E and K—are stored in the fat tissues of the body for a few days to up to 6 months. If you get too much of a fat-soluble vitamin, it can be stored in your liver and may sometimes cause health problems.
If you want to get the most vitamins possible from your food, refrigerate fresh produce and keep milk and grains away from strong light. Vitamins are easily destroyed and washed out during food preparation and storage. If you take vitamin supplements, store them at room temperature in a dry place that's free of moisture.