Vitamin D supplements disappoint again. That’s the conclusion of a meta-analysis published in JAMA Cardiology this week. The researchers noted that many epidemiological studies have linked low vitamin D levels to heart attacks, strokes, heart failure and other cardiovascular problems. Vitamin D is well known to be crucial for maintaining strong bones. Good levels of vitamin D seem to help protect children from air pollution. People with adequate levels of vitamin D seem to be less prone to cancer. Moreover, people with low blood levels of this vitamin are more susceptible to ulcerative colitis. But so far, supplements don’t seem to improve people’s health. This study of vitamin D supplements for heart disease did not change that perception (JAMA Cardiology, June 19, 2019).
How Did the Scientists Study Vitamin D Supplements for Heart Disease?
The researchers reviewed 21 randomized controlled trials involving vitamin D supplements for heart disease. These studies included more than 83,000 participants with an average age around 65. The trials had used a variety of doses and schedules. Altogether, however, the investigators found no indication that vitamin D supplements reduced the risk of cardiovascular events.
Other Vitamin D Supplement Disappointments:
This comes on the heels of a large trial published in the New England Journal of Medicine last week. It demonstrated that people taking 4,000 IU daily of vitamin D3 were no less likely than those on placebo to develop type 2 diabetes.
Studies like this and many others over the years leave patients and doctors in a quandary. Low vitamin D levels are associated with multiple health conditions, but supplements appear to be ineffective for preventing such problems. This is not the first study to show that vitamin D supplements for heart disease are not effective. Unfortunately, it does not tell us how to ensure we have adequate levels of this crucial vitamin circulating in our bodies.