Calcium, vitamin D co-supplementation helps lower diastolic blood pressure

Supplementation with both calcium and vitamin D yields a beneficial effect on diastolic blood pressure (DBP) levels, a study has found.

Researchers performed a systematic review and meta-analysis of trials evaluating the effects of vitamin D and calcium co-supplementation vs placebo on blood pressure (BP) in healthy or unhealthy individuals.

The meta-analysis included eight trials conducted in US (n=2), Canada (n=2) and Asia (n=4). The number of participants varied between 42 and 17,122 (total, n=17,644), with four studies involving healthy adults, two involving patients with type 2 diabetes, one involving overweight and obese individuals, and one involving colorectal adenoma patients.

Pooled data indicated that the intervention led to a nonsignificant reduction in systolic BP compared with control (standardized mean difference, −0.23, 95 percent confidence interval [CI], −0.52 to 0.06). In contrast, co-supplementation produced a statistically significant decrease in DBP (standardized mean difference, −0.29, 95 percent CI, −0.55 to −0.02).

Subgroup analysis showed that the beneficial effects of supplementation with both vitamin D and calcium on DBP were more pronounced in young adults than other age groups.

There was significant heterogeneity regarding the duration of the calcium and vitamin D intervention (6 weeks to 7 years). The calcium dosage used in the trials varied between 500 and 1,200 mg/d, while the vitamin D dosage ranged from 125 to 7,142 IU/d.

More trials are needed to determine the ideal amount of calcium and vitamin D co-supplementation in patients with hypertension before final conclusions can be reached, the researchers said.