In the winter, pre-teen girls may need more vitamin D -- either from diet or supplements -- to have healthy bones, a new study says.
The goal of the study was to figure out how much vitamin D girls aged 11 to 12 would need to take every day in order to keep the levels of this nutrient in their blood at healthy levels. Some experts think that since these girls are growing fast, vitamin D might be particularly important.
Vitamin D aids bone growth by helping the body absorb calcium. An extreme lack of vitamin D can lead to rickets, which causes delayed growth, muscle weakness, and teeth problem in kids. But in the U.S. at least, rickets is rare, according to the Centers for Disease Control and Prevention.
Our skin can make vitamin D when it's exposed to sunlight, or we can get the nutrient in our diet or as supplements.
In the new study, published in the American Journal of Clinical Nutrition, Kevin Cashman, head of the School of Food and Nutritional Sciences at University College Cork in Ireland, and colleagues found that teen girls need a vitamin D intake of about 750 IU per day to have levels in their blood that allow for healthy bone growth.