Role of vitamin D deficiency in cardiovascular disease
- Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Correspondence to Professor Ian Reid, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1132, New Zealand;
Contributors The manuscript was drafted by IR then critically reviewed and revised by MB.
- Received 6 November 2011
- Revised 25 January 2012
- Accepted 31 January 2012
- Published Online First 28 February 2012
Vitamin D is a fat-soluble secosteroid produced in the skin as a result of sunlight exposure, and its circulating levels are reduced in a wide variety of chronic illnesses and obesity. Observational studies clearly demonstrate a higher incidence of cardiovascular events in individuals with low circulating 25-hydroxyvitamin D [25(OH)D]. This relationship can potentially be explained by confounding, because individuals with low 25(OH)D are generally older, frailer, heavier, and have more comorbidities and higher estimated cardiovascular risk than individuals with higher 25(OH)D. The vitamin D receptor appears to be widely distributed, including in cardiovascular tissue, although this has recently been contested. Despite these epidemiological and laboratory findings, meta-analyses of clinical trials have not shown evidence of beneficial effects of vitamin D supplementation on cardiovascular endpoints. Trials are underway to assess these possibilities further. At present, there is insufficient evidence to support vitamin D supplementation for improving cardiovascular outcomes.
Funding This study was supported by the Health Research Council of New Zealand, grant no 09/111.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.