Can Vitamin D deficiency increase risk of heart disease? New Swiss study shows link

The fat-soluble vitamin addresses cumulative risk factors for cardiovascular health, say cardiologists

Written by: Anuradha Mascarenhas

4 min readUpdated: Oct 2, 2023 09:37 PM IST

Vitamin D levels vary by age. (Source: Freepik)

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Can Vitamin D deficiency increase risk of heart disease? New Swiss study shows link

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Can Vitamin D supplements reduce one’s risk of cardiovascular disease? The jury is still out but a recent Swiss Nutrition and Health Foundation study shows strong links between lower vitamin D levels and a higher risk of cardiovascular events.

Top cardiologists feel maintaining normal vitamin D levels provides better health in terms of glucose tolerance, lowering risk of infections, stronger bones and muscular system. And the heart is a muscular organ. “To that extent, there is no doubt that maintaining good Vitamin D levels is essential. However, we need larger randomised controlled trials followed up over a long period of time to conclude that increasing Vitamin D levels would reduce cardiovascular disease. What this study does though is focus on preventive markers in heart care and if encouraging results come in large scale studies, only then can we consider Vitamin D as part of therapy,” says Dr Aparna Jaswal, cardiologist and electrophysiologist at Escorts Heart Institute and Research Centre, New Delhi.

Why is vitamin D good for the heart?

This fat-soluble vitamin, says the Harvard T H Chan School of Public Health, helps keep arteries flexible and relaxed, so that they do not get constricted, which in turn helps control high blood pressure. Many of the body’s organs and tissues have receptors for Vitamin D which suggest an important role for this vitamin. Analysis of multiple studies has shown that people with lowest serum levels of Vitamin D had an increased risk of stroke and heart disease compared with those with the highest levels but the School points out that taking Vitamin D supplements has not been found to reduce cardiovascular risk.

Vitamin D takes care of cumulative risk factors of heart disease

Vitamin D deficiency can be linked to vascular dysfunction, arterial stiffness and left ventricular hypertrophy (increased thickness of the heart muscle). “Blood pressure regulation is also adversely affected by a deficiency of Vitamin D. In people with diabetes, better control of blood sugar levels is facilitated by adequate Vitamin D levels. So, one can say that Vitamin D deficiency aggravates one or more cardiovascular risk factors. Some studies have shown that low vitamin D levels increase levels of low-density lipoprotein (LDL) or bad cholesterol, which again is a risk factor. There have been studies to show a link between vitamin D deficiency and obesity, which is again not desirable as a lifestyle marker. Unchecked, these risk factors can increase the risk of heart attack and stroke,” says Dr Vijay Natarajan, cardiac surgeon and Director of Surgical Services, Bharati Hospital, Pune.

He mentions a recent Australian study published in the British Medical Journal which found that vitamin D supplementation might reduce the incidence of major cardiovascular events, particularly myocardial infarction (heart attack) and coronary revascularisation (need for CABG or angioplasty). “This protective effect could be more marked in those taking cholesterol lowering medications or other cardiovascular drugs at baseline, according to the BMJ study,” Dr Natarajan says. “There is also an interesting finding from the D-Health trial that Vitamin D supplementation might reduce the risk of major cardiovascular events although the absolute risk difference was small,” he adds, arguing for more definitive studies.

How much Vitamin D do you need?

Vitamin D levels vary by age. Normal levels of Vitamin D are between 30 to 50 nmol/L. “The recommended daily requirement of Vitamin D is 600 IU,” says Dr Natarajan. Until then, vitamin D, which is primarily produced by sun exposure and skin synthesis, can be obtained by spending 20 minutes outdoors. And that’s not a tall order for heart health.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More