Why in news?
A clinical trial known as TARGET‑D reported in 2025 that adults who had previously experienced a heart attack and took personalised doses of vitamin D were far less likely to suffer another heart attack. Participants whose blood vitamin D levels were raised to a target range (about 40–80 ng/mL) experienced a 52 percent reduction in recurrent heart attacks compared with those who took standard doses or no supplements. The findings suggest that tailored supplementation might protect the heart when combined with regular monitoring.
Background
Vitamin D is a fat‑soluble nutrient that helps the body absorb calcium and maintain bone health. The skin synthesises vitamin D when exposed to sunlight, particularly ultraviolet‑B radiation; in winter or in people with limited sun exposure, stores can run low. Dietary sources include oily fish (such as salmon and mackerel), fish liver oils, egg yolks and mushrooms, but these are often insufficient to meet daily needs, so many countries fortify milk, cereals and other foods. The recommended intake varies by age, and deficiency is common among people who stay indoors, have darker skin or live in areas with little sunlight.
Vitamin D and the heart
- Calcium regulation: Vitamin D helps control blood calcium levels. Stable calcium is essential not only for bones but also for proper contraction of heart muscles and regulation of blood pressure.
- Immune and anti‑inflammatory effects: Adequate vitamin D levels reduce systemic inflammation and support immune function, which may lower the risk of atherosclerosis and heart failure.
- Deficiency risks: Low vitamin D has been linked in observational studies to hypertension, diabetes and cardiovascular disease, though causality remains a subject of research.
- Personalised dosing: In the TARGET‑D trial, participants’ blood vitamin D and calcium were measured every three months. Supplements were adjusted individually (often more than 5 000 IU per day) to maintain the target range without causing toxicity. Unlike previous trials that used fixed doses, this approach achieved significant reduction in heart attack recurrence.
Significance
- Customised healthcare: The results support the idea that nutrient supplementation should be tailored to individual needs rather than a one‑size‑fits‑all approach.
- Public health insight: Many Indians are deficient in vitamin D due to lifestyle and dietary habits. Awareness of deficiency and routine testing could prevent bone diseases and possibly reduce cardiovascular risk.
- Caution against excess: Vitamin D is fat‑soluble, and excessive intake can cause high calcium levels, leading to nausea, weakness or kidney problems. Supplementation should therefore be supervised by healthcare providers.
Sources: American Heart Association, Times of India, NIH Office of Dietary Supplements