Vitamins are organic compounds found in small quantities in most foods. All vitamins are either fat-soluble or water-soluble. The fat-soluble vitamins (A, D, E, and K) are stored in the liver and fatty tissues until they are needed. The water-soluble vitamins (C and the B complex group) are not stored for any appreciable length of time and must be replenished daily.

Vitamins function as coenzymes that promote the many chemical reactions in the body around the clock. Because vitamin deficiencies result in a variety of diseases and adequate daily intake is necessary, the dietary reference intake (DRI) for most vitamins has been established. Although these amounts are needed to prevent vitamin-deficiency diseases, they do not represent optimal values.

Today, the interest in vitamins by the scientific community goes beyond that. For instance, substantial research efforts currently are attempting to clarify the role of selected antioxidant vitamins (C, E, and the carotenoids) in preventing cardiovascular disease and cancer. The early evidence is promising, and taking these vitamins in amounts larger than recommended seems to be safe.

The antioxidant vitamins protect the body from the harmful effects of free radicals (oxidants). Free radicals are byproducts of oxidation. Because the cells continuously use oxygen, free radicals are being produced constantly. Simultaneously, free radicals are generated by cigarette smoke, radiation from the sun and other sources, alcohol, heat, and environmental pollutants.

If free radicals are not neutralized immediately, they damage the cells and their DNA (the master blueprint for cellular function). Researchers estimate that each DNA of the approximately 60 trillion cells in the body takes “a hit from free radicals every 10 seconds.” Over the course of a lifetime, some of the cellular damage inflicted by free radicals goes unrepaired. The cumulative damage can result in the development of cancer, heart disease, cataracts, and rheumatoid arthritis. Free radicals also have been implicated as an agent that promotes aging. [Read more...]