Vitamin D supplementation did not produce meaningful reductions in blood pressure. Scottish researchers recruited 159 hypertensive patients over the age of 70. They were randomly assigned to receive either vitamin D or placebo in oil every three months for a year. The dose of vitamin D was 100,000 International Units each time.
Based on prior studies, the scientists had hypothesized that these large quarterly doses of vitamin D might lower systolic blood pressure. (Systolic pressure is the higher of the two blood pressure numbers.) Although there was a trend in that direction, the difference was not significant.
Those taking ACE inhibitors like lisinopril or ARBs like valsartan did experience a greater drop in systolic blood pressure if they were taking vitamin D. There were also fewer falls among the vitamin takers, though here again the difference was not significant. Larger randomized trials are being conducted to see whether daily supplementation with vitamin D has a different impact on cardiovascular outcomes.
[JAMA Internal Medicine, online, Aug. 12, 2013]
You can learn more about blood pressure control and vitamin D in our Guide to Blood Pressure Treatment and our Guide to Vitamin D Deficiency.
