Blood 25-hydroxyvitamin D concentration and hypertension: a meta-analysis

Objectives Increasing evidence indicates that vitamin D may influence the risk of hypertension, which is a major risk factor for cardiovascular disease. We conducted a meta-analysis to quantitatively review and summarize the results on the association between blood 25-hydroxyvitamin D concentrations and hypertension. Methods Relevant studies were identified by a search of PubMed and EMBASE databases until November 2010. We also reviewed the references of retrieved articles. We included prospective and cross-sectional studies with blood 25-hydroxyvitamin D concentrations as the exposure and hypertension as the outcome. Studies had to report results as a relative risk or an odds ratio. We used random-effects model. Results Of the 18 studies included in the meta-analysis, 4 were prospective studies and 14 were cross-sectional studies. The pooled odds ratio of hypertension was 0.73 [95% confidence interval (CI) 0.63-0.84] for the highest versus the lowest category of blood 25-hydroxyvitamin D concentration. In a dose-response meta-analysis, the odds ratio for a 40 nmol/l (16 ng/ml) (approximately 2 SDs) increment in blood 25-hydroxyvitamin D concentration was 0.84 (95% CI 0.78-0.90). Conclusion Findings from this meta-analysis indicate that blood 25-hydroxyvitamin D concentration is inversely associated with hypertension. J Hypertens 29:636-645 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.