High-dose vitamin D not found to reduce cardiovascular disease or death.
It has been shown that supplements may help lower cholesterol, improve blood pressure, and reduce overall risks of cardiovascular disease; however, supplements have not been proven to prevent serious health events, such as heart attacks and strokes.
Because vitamin D is found in few foods, supplementation is necessary to ensure that the body functions properly. The vitamin is known to promote bone health, reduce inflammation, and modulate cell growth, neuromuscular and immune functions, according to the National Institutes of Health.
Some studies have found an increasing incidence of patients with heart disease who have low levels of vitamin D, which has caused speculation that the deficiency may be associated with heart disease.
A new study published by JAMA Cardiology explored the effects of high-dose vitamin D on heart disease risks. The authors hypothesized that other studies used dose of the vitamin too low to impact results.
Included in the study were 5108 patients randomized to receive oral vitamin D3 or placebo for 3.3 years. Patients in the intervention group received an initial dose of 200,000 IU of oral vitamin D3 followed by monthly doses of 100,000 IU.
At baseline, approximately 25% of patients were vitamin D deficient, of whom 11.8% developed cardiovascular disease. Similarly, 11.5% of patients in the placebo group developed cardiovascular disease.
The authors also reported similar results for patients with vitamin D deficiency at baseline, including heart attack, angina, heart failure, hypertension, and stroke, according to the study.
Since these results indicate that nearly the same number of patients in both groups developed heart disease, high-dose supplements may not effectively reduce risks.
These findings suggest that monthly high-dose vitamin D may not play a role in reducing the risk of cardiovascular disease (CVD), which is in line with previous findings for lower dose supplements, according to the study.
“This study found that monthly high-dose vitamin D supplementation does not prevent CVD. The effects of daily or weekly dosing on CVD risk require further study,” the authors concluded.