ICMR-NIN Study Finds Vitamin D3 More Effective Than D2 in Supporting Muscle and Heart Health

Vitamin D3 may be more effective than Vitamin D2 in maintaining and restoring skeletal muscle and cardiac function, according to a study conducted by researchers at the ICMR-National Institute of Nutrition (ICMR-NIN), Hyderabad.

The study, titled “Dietary Vitamin D2 Is Less Potent Than Vitamin D3 at Maintaining or Restoring Structure and Metabolism of Skeletal Muscle and Heart in Male Rats,” was published in Molecular Nutrition & Food Research. Researchers examined the comparative effects of Vitamin D2 and D3 on skeletal muscle and heart health in male rats during both the maintenance phase and recovery from vitamin D deficiency.

Vitamin D is primarily known for its role in calcium regulation and bone health, but it also contributes to the functioning of tissues such as skeletal muscle and the heart. While both D2 and D3 are commonly used in supplements and food fortification, researchers noted that their effects on non-bone tissues have not been studied as extensively.

For the study, weaning male Sprague-Dawley rats were divided into groups receiving diets containing Vitamin D2, Vitamin D3, a combination of both, or a vitamin D-deficient diet. Researchers subsequently assessed body composition, muscle strength, muscle structure and metabolism, along with indicators linked to cardiac function.

The findings showed that Vitamin D3 resulted in greater improvements in muscle mass, muscle fibre size and grip strength compared with Vitamin D2. It also demonstrated stronger effects on biological markers associated with muscle development and energy metabolism.

A similar trend was observed in the heart. Vitamin D3 produced greater changes in markers linked to cardiac contractility and metabolism. The differences between the two forms were particularly noticeable when the animals were recovering from Vitamin D deficiency.

Dr Ayesha Ismail, Scientist F at ICMR-NIN and corresponding author of the study, said both forms improved calcium-related parameters, but Vitamin D2 was less effective across several indicators associated with muscle and heart structure and energy metabolism.

ICMR-NIN Director Dr Bharati Kulkarni said the findings suggest that Vitamin D3 could have greater potential than Vitamin D2 in maintaining and restoring skeletal muscle and cardiac functions.

However, the researchers cautioned against directly applying the findings to humans. They said additional research involving human populations is needed to determine whether the observed differences between Vitamin D2 and D3 have similar implications for skeletal and other body functions.

The study adds to existing evidence suggesting that the two forms of Vitamin D may not have identical effects beyond their established role in calcium regulation and bone health. Researchers said further studies will be important in assessing the potential implications for vitamin supplementation and food-fortification programmes.

Source: ANI