Vitamin D and Lipids

The interest in vitamin D has exploded during the last decade, illustrated by the number of new vitamin D–related articles registered in PubMed, which is between 50 and 100 every week. This is also reflected in the lay press, with numerous articles promoting the beneficial effects of the D-lightful sunshine hormone vitamin D. If read uncritically, vitamin D appears to be good for almost any condition thinkable and is today the hottest magic cure. But why has this happened?Article see p 270First of all, vitamin D is nature's own product, an ancient hormone produced in the skin by sun exposure. It promotes the intestinal calcium absorption, has a well-known effect in preventing and curing rickets, and the role of vitamin D in calcium metabolism and skeletal health is indisputable.1 Secondly, the enzyme necessary for the final activation of vitamin D as well as the vitamin D receptor have recently been identified in tissues throughout the body, and extraskeletal effects of vitamin D were therefore to be expected.2 Thus, when methods for measuring 25(OH)D (the most abundant vitamin D metabolite and the one used to evaluate a subject's vitamin D status) became widely available, numerous observational studies were published. And almost without exception, high serum 25(OH)D levels were associated with good health, whereas low levels were predictors of type II diabetes mellitus, cancer, cardiovascular disease, immunologic diseases, and even mortality.3 In 4751 participants in the Tromso study from Northern Norway, over a follow-up period of 11 years those in the lowest serum 25(OH)D quartile had a 32% increased mortality risk as compared with those in the highest 25(OH)D quartile.4 And similarly, in the 1739 subjects in the Framingham Offspring Study followed for 5.4 years, those with serum 25(OH)D levels <10 ng/mL had a hazard ratio …