Listen to the article
Daily Vitamin D3 Supplementation Halves Heart Attack Recurrence Risk, Study Finds
People who have suffered a cardiac arrest could significantly reduce their risk of experiencing a second heart attack through a simple daily vitamin regimen, according to groundbreaking new research.
A large-scale randomized clinical trial conducted at Intermountain Health in Salt Lake City, Utah, has revealed that targeted vitamin D3 supplementation can cut the risk of a second heart attack by half in patients who have already experienced one.
The findings, presented Sunday at the 2025 American Heart Association Scientific Sessions in New Orleans, highlight a potentially transformative approach to cardiovascular care that is both accessible and non-invasive.
The study, called TARGET-D, followed 630 patients between April 2017 and May 2023 who had experienced a heart attack within the previous month. Researchers made a notable discovery at the outset—85 percent of these patients had insufficient vitamin D3 levels, underscoring a widespread deficiency issue.
“Up to two-thirds of people worldwide have low levels of vitamin D,” said lead researcher Heidi May, Ph.D., a cardiovascular epidemiologist at Intermountain Health. She noted that while sun exposure remains the most natural source of vitamin D, lifestyle changes in recent years have reduced many people’s exposure to sunlight.
Participants in the study were divided into two groups: one received targeted vitamin D3 treatment aimed at raising blood levels above 40 nanograms per milliliter (40 ng/mL), while the control group did not receive supplementation. To ensure proper dosing, researchers checked vitamin D blood levels annually and adjusted supplementation accordingly.
More than half of the treatment group required an initial dose of 5,000 international units (IU)—substantially higher than the 600 to 800 IU typically recommended for adults to maintain levels between 30 and 50 ng/mL.
The researchers monitored participants until March 2025 to track cardiovascular outcomes. Of the 630 patients in the study, 107 experienced a major cardiac event during the follow-up period. The data revealed that patients receiving targeted vitamin D3 supplementation had half the risk of experiencing a second heart attack compared to those who did not.
“We’re excited about these results, but we know we have further work to do to validate these findings,” May said, adding that no adverse outcomes were observed even with the higher supplementation doses used in the study.
The findings add significant weight to a growing body of evidence connecting vitamin D to heart health. Dr. Bradley Serwer, a Maryland-based interventional cardiologist and chief medical officer at VitalSolution, who was not involved in the study, noted that the connection between vitamin D and cardiovascular health has been recognized for some time.
“Previous studies have established a correlation between low serum vitamin D levels and an elevated risk of hypertension, coronary artery disease, stroke and heart failure,” Serwer explained. However, he pointed out that prior research failed to demonstrate the effectiveness of vitamin D supplements in reducing heart attack risk, often because “these studies prescribed a standard replacement dosage that was often insufficient to restore healthy vitamin D levels.”
Dr. Marc Siegel, a medical analyst, emphasized that vitamin D functions “more as a hormone than a vitamin” and is “crucial to organ function, including the heart.” He explained that vitamin D deficiency can lead to inflammation and blood clotting, while normal levels have been shown to decrease coronary artery disease, heart failure, and stroke.
While the findings are promising, experts caution that the results may not apply equally to lower-risk populations, as the study focused specifically on high-risk patients who had already experienced a heart attack.
“Further research is necessary to assess the efficacy of vitamin D supplementation in lower-risk individuals,” Serwer noted. “If vitamin D levels are within the normal range, the evidence regarding the benefits of additional supplementation is inconclusive.”
Nevertheless, the study represents a significant step forward in understanding how a relatively simple nutritional intervention might provide substantial protection for those at highest risk of cardiovascular events, potentially transforming preventative care for heart attack survivors.
Fact Checker
Verify the accuracy of this article using The Disinformation Commission analysis and real-time sources.
10 Comments
This is an encouraging finding, especially given the prevalence of vitamin D deficiency worldwide. I hope the results can be validated in larger trials and potentially lead to new clinical guidelines.
Agreed. Wider access to affordable vitamin D supplements could make a real difference in reducing heart disease risk for many people.
While the findings are promising, I’m curious to see how the results hold up in longer-term follow-up studies. Reducing heart attack recurrence risk by 50% is a substantial claim that warrants further scrutiny.
That’s a fair point. Replicating the results in larger, more diverse patient populations over an extended period will be crucial to validating the long-term efficacy of this approach.
Interesting research on vitamin D3 supplementation potentially reducing heart attack recurrence risk. I wonder if this could have broader implications for preventative heart health strategies beyond just post-heart attack patients.
That’s a good point. If the benefits hold true for a wider population, it could be an affordable and accessible way to support cardiovascular health.
This research highlights the importance of addressing underlying nutritional deficiencies, which are often overlooked in cardiovascular care. I hope it encourages more holistic approaches to heart health.
Absolutely. Integrating nutritional screening and supplementation into standard cardiac treatment protocols could yield significant benefits for patients.
It’s intriguing that such a simple, low-cost intervention like vitamin D3 supplementation could have such a substantial impact on heart attack recurrence rates. I’m curious to see if the benefits extend to prevention as well.
That’s a good question. If the preventative effects are proven, it could be a game-changer for public health approaches to cardiovascular disease.