ICMR-National Institute of Nutrition (ICMR-NIN), Hyderabad, researchers have found that vitamin D3 is more effective than vitamin D2 in maintaining and restoring muscle and heart function, at least in animal studies in their latest study.

What does Vitamin D do to body?

Vitamin D is widely known for its role in maintaining bone health and regulating calcium levels. However, it also plays an important role in the functioning of skeletal muscles and the heart. The nutrient is available mainly in two forms: vitamin D2 and vitamin D3, both of which are commonly used in supplements and food fortification programmes.

Researchers conducted experiments on weaning male Sprague-Dawley rats to compare them. The animals were fed diets containing vitamin D2, vitamin D3, a combination of both, or a vitamin D-deficient diet. The team then evaluated body composition, muscle strength, muscle structure, energy metabolism and markers linked to heart function.

They found that rats receiving vitamin D3 showed greater improvements in muscle mass, muscle fibre size and grip strength than those given vitamin D2. Vitamin D3 was also more effective in enhancing biological markers associated with muscle growth and energy metabolism.

Similar benefits were also found in heart health as Vitamin D3 produced stronger effects on indicators of cardiac contractility and metabolism, especially among rats recovering from vitamin D deficiency. Scientist Ayesha Ismail, also the corresponding author of the study, said that while both forms of vitamin D improved calcium-related parameters, vitamin D2 was less effective in several measures related to muscle and heart structure and energy metabolism.

ICMR-NIN Director Bharati Kulkarni said the findings suggest that vitamin D3 may be a better option for maintaining and restoring muscle and cardiac functions. However, she cautioned that further studies are required to better understand the effects of the two forms of vitamin D and their implications for supplementation and food fortification programmes, as per a press release.