A new study reveals that a personalized, monitored approach to vitamin D3 supplementation after a heart attack can dramatically cut the risk of a second heart attack.
A new study from heart specialists at Intermountain Health in Salt Lake city reports that a personalized method of vitamin D3 supplementation can greatly lower the chances of a second heart attack in patients who have already experienced one.
in a large randomized clinical trial,researchers discovered that using a “target to treat” strategy-where patients’ vitamin D levels were routinely measured and supplement doses were adjusted to reach an optimal range-cut the risk of another heart attack by 50 percent.
The findings were recently unveiled at the 2025 American Heart Association Scientific Sessions in New Orleans.The results are promising, said Heidi May, PhD, cardiovascular epidemiologist at Intermountain Health and principal investigator of the study.
“we observed no adverse outcomes when giving patients higher doses of vitamin D3 supplementation, and to significantly reduce the risk of another heart attack, which are exciting results,” said Dr. May.”We’re excited wiht these results but know we have further work to do to validate these findings.”
This research carries broad importance, as an estimated one-half to two-thirds of the global population has insufficient levels of vitamin D.
Changing Lifestyles and Vitamin D Deficiency
In the past, people typically received sufficient vitamin D through regular sunlight exposure. Today, lifestyle changes and medical advice aimed at reducing skin cancer risk have led many to spend less time in the sun. Consequently, maintaining healthy vitamin D levels now often depends on choice sources, including vitamin D3 supplements.
While numerous observational studies have linked low vitamin D levels to poorer heart health, earlier clinical trials using standard supplement doses did not show improvements in cardiovascular risk. This led Intermountain heart researchers to question whether achieving a specific blood level of vitamin D might be more effective than simply giving a uniform supplement dose to all patients.