Vitamin D3 halves risk of second heart attack with tailored dosing approach

Credit: Getty Images/TanyaJoy

By Claudia Tanner

A novel "treat-to-target" approach to vitamin D3 supplementation has demonstrated a 50% reduction in a second heart attack in patients who have already experienced one.

That’s according to findings from the TARGET-D trial presented at the American Heart Association Scientific Sessions 2025 in New Orleans.

Patients’ blood levels of vitamin D3 were monitored and dosing adjusted to achieve optimal levels above 40 ng/mL in the randomised clinical trial of 630 patients.

“Previous studies just gave patients supplementation without regularly checking blood levels of vitamin D to determine what supplementation achieved,” said Dr Heidi May, cardiovascular epidemiologist at Intermountain Health and principal investigator of the study .

“With more targeted treatment, when we checked exactly how supplementation was working and made adjustments, we found that patients had their risk of another heart attack cut in half.”

Higher doses than current recommendations

The TARGET-D trial enrolled the patients between April 2017 and May 2023, all of whom had experienced an acute myocardial infarction within one month of enrolment. Participants were followed through to March 2025 for cardiovascular events.