Q: I get a health newsletter from a respected medical center. I noticed in the last issue that vitamin D could raise the risk of heart attack and stroke by up to 20 percent. Any comments?
A: Several research reports have created considerable confusion. A year ago, researchers reported that people taking calcium supplements were 30 percent more likely to have a heart attack than those getting placebos (BMJ online, July 29, 2010). Although this finding came from a meta-analysis of 11 studies involving more than 12,000 people, many health professionals were skeptical and objected that vitamin D intake was not part of the analysis.
This year, a new study in BMJ (online, April 19, 2011) confirmed the original finding with a twist. Even women taking vitamin D with their calcium had a higher risk (20 percent) of heart attack or stroke compared with placebo. We suspect that this is what your newsletter was reporting.
More recent research shows that vitamin D alone appears to protect men from heart attacks and strokes (American Journal of Clinical Nutrition online, June 8, 2011).
Excess calcium may be the culprit, while vitamin D may be neutral or protective for the heart