Back to the future: a new look at ‘old’ vitamin D

• Published in: Journal of endocrinology Vol. 198; no. 2; pp. 261 - 269
• Main Authors: Chun, Rene F, Adams, John S, Hewison, Martin
• Format: Journal Article
• Language: English
• Published: Bristol BioScientifica 01.08.2008
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Humans; Immunity, Innate - physiology; Macrophages - metabolism; Protein hormones. Growth factors. Cytokines; Proteins; Review; Signal Transduction - physiology; Vitamin D - metabolism; Vitamin D - physiology; Vitamin D Deficiency - physiopathology; Hormone; Rodentia; Lipids; Steroid hormone receptor; Review; Phylogeny; Cholesterol; Signal transduction; Vertebrata; Mammalia; Mouse; Vitamin D; Biological receptor
• ISSN: 0022-0795; 1479-6805
• DOI: 10.1677/JOE-08-0170

Our perception of the vitamin D system continues to evolve. Recent studies have re-evaluated the parameters for adequate vitamin D status in humans, revealing a high prevalence of insufficiency in many populations throughout the world. Other reports have highlighted the potential consequences of vitamin D insufficiency beyond established effects on bone homeostasis. Most notably, there is now strong evidence of a role for vitamin D in modulating innate and adaptive immunities, with insufficiency being linked to infectious disease and other immune disorders. To date, signaling pathways for these new responses to vitamin D have been based on established endocrine models for active 1,25-dihydroxyvitamin D, despite present evidence for more localized, intracrine modes of action. In the following review, we provide a fresh perspective on vitamin D signaling in non-classical target cells such as macrophages by highlighting novel factors associated with the transport and action of this pluripotent secosteroid.