Vitamin D 201 3: Where do the hyperbole end and the facts begin?

摘要

Numerous beneficial effects of an adequate vitamin D status over a wide range of clinical conditions are being proposed, generating an unprecedented level of interest in the medical and lay press alike translating into great public interest in vitamin D. Much of this interest originates from reports of simple associations between a particular disease state or condition and low vitamin D status. Thus the evidence can be very weak and there are numerous knowledge gaps. An improved vitamin D status can be associated with many attributes of good health relating to mobility and activities providing sunlight exposure without the involvement of a direct biological action of vitamin D. However, during the twenty-first century, there has been a flowering of knowledge of vitamin D metabolism within a wide range of tissues, including synthesis of the active metabolite 1,25-dihydroxyvitamin D (1,25D) and activation of the vitamin D receptor within the tissue of synthesis.Most organs and tissues therefore respond to vitamin D. Such information provides plausible physiological and molecular mechanisms for a diverse array of activities and tissue responses that could improve health.