WASHINGTON: Higher levels of Vitamin D have been associated with better muscle strength in girls.
According to the study's first author, medical student Rada Faris Al-Jwadi, girls with low vitamin D have a 70 per cent increased risk of being among the lowest 10 per cent in a test for muscle strength.
The study also found that girls were stronger if their Vitamin D level was more than 50 nmol/L. The most surprising finding was that this difference was only evident in girls and not in boys.
The study shows no association with vitamin D levels in mothers during pregnancy or in the umbilical cord at birth. This leads to the conclusion that there is no prenatal programming effect on muscle strength. We are talking about a more immediate effect of Vitamin D, says Rada Faris Al-Jwadi.
According to Henrik Thybo Christesen, the study offers no explanation for the difference between boys and girls.
But other studies on children and adults have shown that vitamin D increases the levels of IGF-I (Insulin-like growth factor 1), which is a growth factor that increases muscle strength.
"Also, the IGF-I level is different in boys and girls which could be part of the explanation. We can't, based on our data, conclude that girls will get stronger muscles if they got more vitamin D through their food, as supplement pills or because of more sun exposure which are some of the most important sources of Vitamin D. Even though, our association could mean exactly that," Christesen said.
The study has been published in the 'Journal of Clinical Endocrinology and Metabolism.'