Abstract
CONTEXT: Evidence for a beneficial role of vitamin D on blood pressure (BP) outcomes is inconclusive. OBJECTIVE: This work aimed to investigate the effect of 2 doses of cholecalciferol (vitamin D(3)) supplementation coadministered with calcium on systolic blood pressure (SBP) and diastolic blood pressure (DBP). METHODS: Exploratory analyses were conducted from a 1-year, multicenter, double-blind, randomized controlled trial (RCT). Total of 221 ambulatory older overweight individuals received calcium dose and oral vitamin D(3), at the equivalent of 600 IU/day or 3750 IU/day. RESULTS: SBP and DBP decreased significantly in the overall group, and in the high-dose group at 6 and 12 months. Similar trends were observed in the low-dose group, but did not achieve statistical significance. In participants with a body mass index (BMI) greater than 30, SBP decreased significantly in both treatment groups whereas DBP significantly decreased in the high-dose group only. In the subgroups of hypertensive participants (N = 143), there was a decrease in SBP and DBP at 6 and 12 months, with both vitamin D doses and independently of BMI levels. Using multivariate linear mixed models with random effects in the overall group of participants, SBP at 6 and 12 months was significantly predicted by BMI (β = .29; P = .05) and by baseline SBP (β = .16; P < .001), but not by vitamin D treatment dose. CONCLUSION: Vitamin D and calcium decrease SBP and DBP in overweight older individuals, but more is not necessarily better. This effect is seen in individuals with BMI greater than 30, in hypertensive patients, and seems to be largely independent of dose.