Eur J Epidemiol. 2013 Mar 2.
Kunutsor SK, Apekey TA, Steur M.
Department of Public Health and Primary Care, University of Cambridge, Cambridge, CB1 8RN, UK, skk31 at cantab.net.
The evidence on the association between baseline vitamin D status and risk of incident hypertension in general populations is limited and has not been reliably quantified. We conducted a systematic review and meta-analysis of published prospective studies evaluating the associations of baseline vitamin D status (circulating 25-hydroxyvitamin D [25(OH)D] levels and dietary vitamin D intake) with risk of hypertension. Eligible studies were identified in a literature search of MEDLINE, EMBASE, and Web of Science up to November 2012. Pooled relative risks (RRs) with 95 % confidence intervals were calculated using random effects models. Generalized least-squares trend estimation was used to assess dose-response relationships.
Of the 2,432 articles reviewed for eligibility, eight unique prospective cohorts with aggregate data on 283,537 non-overlapping participants and 55,816 incident hypertension cases were included.
The RRs (95 % CIs) for hypertension in a comparison of extreme thirds of baseline levels of vitamin D were 0.70 (0.58, 0.86) for seven studies that measured blood 25(OH) D levels and 1.00 (0.95, 1.05) for four studies that assessed dietary vitamin D intake.
The pooled RR of incident hypertension per 10 ng/mL increment in baseline 25(OH)D levels was 0.88 (0.81, 0.97) in dose-response analysis. Evidence was lacking of heterogeneity among studies that measured blood 25(OH) D levels and those that assessed dietary vitamin D status. Studies are needed to determine whether the association of vitamin D with hypertension represents a causal association and also to determine whether vitamin D therapy may be beneficial in the prevention or the treatment of hypertension.