ICMR-NIN study finds vitamin D3 more effective than D2 for muscle, heart health
HYDERABAD: Vitamin D3 was more effective than vitamin D2 in maintaining and restoring skeletal muscle and heart function in male rats, a study by researchers at the Indian Council of Medical Research-National Institute of Nutrition (ICMR-NIN), Hyderabad, has found.
The difference between the two forms was more pronounced when the animals were recovering from vitamin D deficiency, the researchers said.
Researchers compared muscle strength, structure and energy metabolism
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 compared vitamin D2 and vitamin D3 and examined their effects on skeletal muscle and cardiac parameters during maintenance and recovery from vitamin D deficiency.
Vitamin D is known for its role in calcium regulation and bone health. It also has functions in tissues such as skeletal muscle and the heart.
The researchers used weaning male Sprague-Dawley rats and fed them diets containing vitamin D2, vitamin D3, a combination of the two forms, or a vitamin D-deficient diet.
They assessed body composition, muscle strength, skeletal muscle structure and metabolism, as well as markers related to cardiac function.
D3 showed greater effects on muscle and cardiac markers
The study found that vitamin D3 was more effective in improving muscle mass, muscle fibre size and grip strength. It also showed greater effects on markers linked to muscle development and energy metabolism.
Vitamin D3 had stronger effects on markers of cardiac contractility and metabolism, particularly during recovery from deficiency, the researchers said.
“Although both forms of vitamin D were effective in improving calcium-related parameters, vitamin D2 was less effective than vitamin D3 in several parameters related to muscle and heart structure and energy metabolism,” said Dr Ayesha Ismail, Scientist-F and corresponding author of the study.
ICMR-NIN director Dr Bharati Kulkarni said the findings indicated that vitamin D3 may be more effective than vitamin D2 in maintaining and restoring skeletal muscle and cardiac functions.
“Further studies are needed to establish the effects of the two forms of vitamin D on skeletal and extra-skeletal functions and their implications for supplementation and fortification programmes,” she said.
The findings are from an animal study involving male rats. Further research would be needed to establish whether the differences observed apply to humans.
