AHA 2025: Targeted vitamin D dosing cuts repeat MI risk in half

Results from the preliminary phase 3 TARGET-D trial presented at the AHA Scientific Sessions 2025 suggest that adults with heart disease who had a prior MI and received tailored vitamin D₃ supplements—adjusted every 3 months to reach blood concentrations of 40–80 ng/mL—experienced a 52% reduction in recurrent MI vs. controls. Over 4 years, 85% of participants began with insufficient vitamin D levels, and about half required ≥5,000 IU/day—significantly more than the standard 600–800 IU. No significant differences were observed in stroke, heart failure hospitalizations, or mortality, and no adverse events were reported.

Clinical takeaway: Although these findings suggest potential benefits from monitoring vitamin D levels and individualizing supplementation, clinicians should interpret the results cautiously until they're confirmed in peer-reviewed publications.

Source:

American Heart Association. “Heart attack risk halved in adults with heart disease taking tailored vitamin D doses.” News release, Nov. 9, 2025. https://newsroom.heart.org/news/heart-attack-risk-halved-in-adults-with-heart-disease-taking-tailored-vitamin-d-doses.