Taking vitamin D supplements linked to increased chances of avoiding heart attacks

QUEENSLAND, Australia —Vitamin D is probably most synonymous with sunshine and strong bone health, but new Australian research suggests that a regular regimen of vitamin D supplementation can also go a long way in promoting robust heart health. The study, based on a clinical trial, finds that vitamin D supplements may reduce the risk of serious cardiovascular events such as heart attacks among the elderly (age 60+).

The study authors point out that the absolute risk difference was small, but at the same time this was the largest study of its kind to date. Further evaluations are undoubtedly needed, especially among those taking statins or other drugs for cardiovascular disease.

Cardiovascular disease (CVD) is an umbrella term that encompasses all conditions affecting the heart or blood vessels and is a leading cause of death globally. CVD events such as heart attacks and strokes are expected to increase as populations continue to live longer and chronic diseases become increasingly common.

Previous observational studies have consistently noted a link linking vitamin D levels and CVD risk, but to date randomized controlled trials have produced no evidence that vitamin D supplements prevent cardiovascular events, likely due to differences in study design. can influence the results.

To address this issue, the research team in Australia assessed whether supplementing older adults with monthly doses of vitamin D would alter the rate of major cardiovascular events. This D-Health Trial was conducted between 2014 and 2020 and included 21,315 Australians (ages 60-84). Participants received a 60,000 IU vitamin D capsule (10,662 people) or a placebo (10,653 people) to take orally at the start of each month for up to five years.

Those with a history of high calcium levels (hypercalcemia), an overactive thyroid (hyperparathyroidism), kidney stones, soft bones (osteomalacia), sarcoidosis, an inflammatory disease, or anyone already taking more than 500 IU/day of vitamin D were excluded from the ‘experiment .

Next, the research team used data on hospital admissions and deaths to identify major cardiovascular events such as heart attacks, strokes and coronary revascularization (a treatment to restore normal blood flow to the heart).

The median duration of treatment was five years, with over 80% reporting taking at least 80% of the tablets. Over the course of the study, 1,336 participants experienced a major cardiovascular event (6.6% in the placebo group, 6% in the vitamin D group). Meanwhile, the rate of major cardiovascular events was 9% lower in the vitamin D cohort than in the placebo group (equivalent to 5.8 fewer events per 1,000 people).

The rates of heart attack (-19%) and coronary revascularization (-11%) were lower in the vitamin D group, but the team saw no difference in the stroke rate between the two cohorts. Notably, there were some indications of a stronger effect in those using statins or other cardiovascular drugs at the start of the study. However, the researchers clarify that these results were not statistically significant.

Overall, an estimated 172 people would need to take vitamin D supplements monthly to prevent a major cardiovascular event from occurring.

In conclusion, the study authors acknowledge that a small underreporting of events may have occurred and these findings may not apply to other populations, particularly populations in which a higher proportion of people are vitamin D deficient. However, this project was still a very large study with extremely high retention and adherence, as well as a nearly complete dataset covering cardiovascular events and mortality outcomes. The researchers believe their findings suggest that vitamin D supplementation may reduce the risk of major cardiovascular events.

“This protective effect may be more pronounced in those taking statins or other cardiovascular drugs at baseline,” the researchers add in a news release, suggesting that further evaluation is needed to help clarify this issue.

Meanwhile, these findings suggest that conclusions that vitamin D supplementation does not alter cardiovascular disease risk are premature, the study authors conclude.

The study is published in The BMJ.