More Information About the Link Between Vitamin D and Heart Disease

Since the discovery of the vitamin D receptor in cardiovascular tissues in the 1980s, research continues to explore the relationship between vitamin D and cardiovascular health. To date, studies have demonstrated that vitamin D reduces cardiovascular inflammation, regulates the renin-angiotensin-aldosterone system, and inhibits the proliferation of vascular smooth muscle. Clinical trials are also demonstrating that vitamin D supplementation is an effective intervention strategy. This includes a new study recently published in BMJ. 

The D-Health Trial

The D-Health randomized controlled trial from Australia featured more than 21,000 participants aged 69 to 84 and looked at major cardiovascular events including myocardial infarction, stroke, and coronary revascularization. Participants were followed for up to five years with the intervention group receiving 2,000 IU of vitamin D daily compared to placebo. The rate of major cardiovascular events, including myocardial infarction and coronary revascularization, was nine percent lower in the vitamin D group. The rate of heart attack was 19 percent lower in the vitamin D group compared to placebo. Vitamin D’s protective effects were even more pronounced in individuals who were taking statins or other cardiovascular drugs at baseline. There was no difference in the rate of stroke between the two groups.

One interesting aspect of the D-Health trial is that it featured participants who were not deficient in vitamin D. This is significant because previous research showed that vitamin D is only beneficial in patients who are deficient and does not provide cardiovascular benefit to vitamin D-sufficient individuals.

Vitamin D Deficiency

Vitamin D levels are clearly linked to cardiovascular health. A 2022 analysis demonstrated a direct causal effect for a linear association between vitamin D deficiency and heart failure risk. In addition, this analysis showed that lower serum vitamin D levels were also associated with a poor prognosis for heart failure. That analysis found that vitamin D supplementation may help prevent heart failure, which is consistent with previous research from 2014.

A 2020 review of four different studies involving patients with coronary artery disease and vitamin D deficiency also found that vitamin D supplementation improved cardiac outcomes. 

Clinical Direction

While the researchers of the D-Health trial note that the risk difference was small, they also highlight the fact that this was the largest trial of its kind completed to date, and because of their results further research is warranted. Dosage has often come up as a point of debate so further research is needed to help clarify appropriate vitamin D dosages for specific patient populations.

The growing data, including the most recent BMJ trial, clearly indicates that certain individuals may benefit from vitamin D supplementation including those who are deficient, individuals with cardiovascular disease or a history of cardiovascular disease, and people taking cardiovascular medications.