Could Vitamin D Supplements Effectively Reduce Hypertension?

Since vitamin D supplementation does not effectively lower blood pressure (BP), it should not be used as an antihypertensive treatment, according to a recent study.

In the past, low levels of vitamin D have been linked to elevated BP and a heightened risk of future cardiovascular events. However, it was unclear whether the use of vitamin D supplements decreased BP and what characteristics predicted a response.
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Researchers included data extraction from 4541 participants from 46 randomized placebo-controlled clinical trials that used vitamin D supplementation for a 4-week minimum and reported BP data at baseline and after follow-up. Studies noting the use of active or inactive forms of vitamin D or vitamin D analogues were also included.

“We extracted data on baseline demographics, 25-hydroxyvitamin D levels, systolic and diastolic BP (SBP and DBP), and change in BP from baseline to the final follow-up. Individual patient data on age, sex, medication use, diabetes mellitus, baseline and follow-up BP, and 25-hydroxyvitamin D levels were requested from the authors of the included studies,” said the study’s authors.

“For trial-level data, between-group differences in BP change were combined in a random-effects model,” they said.

For the individual patient data, investigators calculated the BP differences between the groups at the final follow-up evaluation and adjusted for the baseline blood pressure before they combined the results in a random-effects model.

The meta-analysis findings showed that within both the trial level and the individual patient level, vitamin D supplementation did not majorly impact diastolic or systolic blood pressure.

Similar findings were displayed in the subgroup analyses limited to diabetes patients or those with elevated blood pressure at baseline.

The complete study is published in the March issue of JAMA Internal Medicine.

-Michelle Canales Butcher

Reference:

Beveridge LA, Struthers AD, Khan F, et al. Effect of vitamin D supplementation on blood pressure. JAMA Intern Med. 2015 March [epub ahead of print] doi: 10.1001/jamainternmed.2015.0237.