Vitamin D3 Shows Greater Benefits Than D2 for Muscle and Heart Health: ICMR Study - Video

Could the type of vitamin D matter as much as the dose when it comes to protecting muscle and heart health?

A new study from the Indian Council of Medical Research-National Institute of Nutrition (ICMR-NIN), Hyderabad, suggests vitamin D3 may be more effective than vitamin D2 at maintaining and restoring skeletal muscle and cardiac function. The findings were published in Molecular Nutrition and Food Research.

Researchers compared vitamin D2 and D3 in male Sprague-Dawley rats during vitamin D maintenance and recovery from deficiency. The animals received diets containing D2, D3, a combination of both, or no vitamin D. Researchers assessed body composition, muscle strength, fibre size, muscle metabolism and markers of cardiac function.

Vitamin D3 produced greater improvements in muscle mass, muscle fibre size and grip strength, alongside changes in markers involved in muscle development and energy metabolism. It also showed stronger effects on markers of cardiac contractility and metabolism, particularly during recovery from vitamin D deficiency.

Vitamin D3 is produced in the skin after sunlight exposure and is found mainly in animal foods and supplements. Vitamin D2 comes from sources including mushrooms and yeast and is also used in food fortification.

The findings matter because vitamin D deficiency is widespread globally, affecting over 1 billion people. However, the research was conducted in male rats, so the results cannot yet be assumed to apply to people.

The researchers say further human studies are needed to determine whether D3 offers greater benefits than D2 for skeletal muscle, heart function and other health outcomes, and whether this should influence supplementation and fortification strategies.

REFERENCE: S. Dutta, A. Anilkumar S, M. Urooj, and A. Ismail, “ Dietary Vitamin D2 Is Less Potent Than Vitamin D3 at Maintaining or Restoring Structure and Metabolism of Skeletal Muscle and Heart in Male Rats.” Molecular Nutrition & Food Research 70, no. 16 (2026): e70588. https://doi.org/10.1002/mnfr.70588