ABSTRACT

Vitamin D is a fascinating vitamin that is quite unique. There are four forms of it in the body, only one of which is active. Unlike any other vitamin, the metabolism of vitamin D follows a circuitous route in the body involving the skin, the liver, and the kidney. Fat cells present a problem to obese individuals who require larger doses of vitamin D supplements to achieve serum levels comparable to those of normal weight. Today a number of claims have been made that adequate levels of vitamin D are beneficial for the prevention of a range of health problems, from heart disease and cancer to diabetes. A large and growing number of epidemiological and observational studies show that adequate levels of vitamin D intake or synthesis reduce the risk of developing various cancers. While sunscreens help to protect against skin cancer and aging, they limit vitamin D production, causing a greater risk of other cancers.