Personalized Vitamin D3 Therapy Halves Risk of Second Heart Attack

A new study by Intermountain Health, Salt Lake City, suggests that optimizing vitamin D3 levels after a heart attack can significantly lower the risk of recurrence. Presented on November 9 at the 2025 American Heart Association Scientific Sessions, the TARGET-D trial found that patients whose vitamin D levels were closely monitored and adjusted to an optimal range had a 50% lower chance of a second heart attack.

The trial, involving 630 patients, used a “target-to-treat” approach—regularly checking vitamin D levels and modifying doses to maintain concentrations above 40 ng/mL. More than half required doses of 5,000 IU, well above standard recommendations.

Lead investigator Dr. Heidi May reported no adverse effects from higher doses, calling the findings “exciting and encouraging.” Given that up to two-thirds of people worldwide are vitamin D deficient, researchers plan larger trials to confirm whether targeted supplementation can further reduce cardiovascular risks.

10-11-2025