Girls are stronger with higher levels of vitamin D.This association was not found in boys. These are the results from a new large study from the Odense Child Cohort. This was recently published in the Journal of Clinical Endocrinology and Metabolism.
They 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.
In this study, 881 5-year-old children in Odense Child Cohort got their muscle strength measured with a standardized test for hand grip strength meant for children.
For 499 of the children, Vitamin D status analyses were done.
Low Vitamin D levels were defined as serum 25OH-Vitamin D below 50 nmol/L.
The statistical analyses were adjusted for height, weight and body fat percentage and were statistically highly significant.
This means that the association wasn't due to being overweight and thereby having lower Vitamin D and lower muscle strength. It also means that it wasn't because girls liked to be more inside and were less physically active.
The study shows no association with vitamin D levels in mothers during pregnancy or in the umbilical cord at birth.
Other studies on children and adults have shown that vitamin D increases the levels of IGF-I, 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.