Vitamin D metabolism and molecular modes of action: new insights into vitamin D activities

Abstract

Reports of significant health benefits from an adequate vitamin D status continue to generate considerable interest. Knowledge of the molecular actions of the vitamin D system, including the nuclear vitamin D receptor and other receptors for 1,25-dihydroxy vitamin D and vitamin D status, provides evidence for vitamin D system to exert biological activities with physiological sensitivities and specificities across a wide range of tissues in a similar manner to other nuclear receptor hormones. This knowledge provides physiological plausibility for the wide range of activities claimed for vitamin D from largely observational studies and supports proposals for well-conducted clinical trials.