Key Highlights
- Vitamin D levels optimized for heart health reduced risk of another heart attack by 52% in adults with previous heart attacks.
- More than 85% of participants had vitamin D levels below 40 ng/mL at study enrollment.
- Nearly 52% of treatment group needed over 5,000 IU daily to achieve target blood levels above 40 ng/mL.
- Optimal vitamin D levels were maintained between 40-80 ng/mL.
Vitamin D Dosage Personalization in Heart Disease Management
New research presented at the American Heart Association’s Scientific Sessions 2025 highlights a groundbreaking approach to managing heart disease through personalized vitamin D supplementation. The study, known as TARGET-D (Tailored Vitamin D for Risk Reduction Trial), focuses on optimizing vitamin D levels to reduce the risk of recurrent heart attacks in adults who have already experienced one.
Dr. Heidi T.
May, principal investigator of TARGET-D and an epidemiologist at Intermountain Health, explains that previous research has linked low vitamin D levels with worse cardiovascular health outcomes. However, this study takes a novel approach by tailoring the doses to achieve optimal blood levels for each participant. “We checked each participant’s vitamin D levels at enrollment and throughout the study, adjusting their dose as needed to bring and maintain them in a range of 40-80 ng/mL,” said Dr. May.
Study Design and Findings
The TARGET-D randomized clinical trial involved over 600 adults with acute coronary syndrome who had previously experienced a heart attack. Participants were randomly assigned to either a standard care group, which did not receive vitamin D monitoring or dose-tailoring, or a treatment group where personalized dosing was used.
Key findings indicate that those in the treatment group saw a significant reduction in their risk of another heart attack. According to Dr. May, “People who received personalized dosing of vitamin D supplements had a 52% lower risk of having another heart attack compared to participants whose levels were not managed.” This is a substantial improvement over previous studies that used standard doses for all participants.
Challenges and Recommendations
The study also faced several challenges. Over 85% of participants began with vitamin D levels below the recommended threshold, indicating a significant deficiency in this population. Additionally, nearly half of those in the treatment group required more than 5,000 IU daily to reach target blood levels, highlighting the importance of personalized dosing.
Dr.
May emphasizes that these results could have important implications for patient care. “We encourage people with heart disease to discuss vitamin D blood testing and targeted dosing with their healthcare professionals to meet their individual needs,” she said. While the study showed promising outcomes specifically in preventing heart attacks, it did not significantly reduce other serious events such as heart failure hospitalizations or strokes.
These findings underscore the need for further research to confirm these results in larger populations and across different racial and ethnic backgrounds. The American Heart Association recommends that individuals with heart disease consult their cardiologists before making any changes to their vitamin D regimen, especially given potential risks associated with excessive levels.
Conclusion
The TARGET-D study provides valuable insights into the role of personalized vitamin D management in reducing the risk of recurrent heart attacks. As research continues, healthcare providers may adopt more tailored approaches to address individual deficiencies and optimize patient outcomes for those at risk of cardiovascular disease.
