Pre-teen girls need vitamin D?
To have healthy bones pre-teen girls may need more vitamin D in winter.
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.
Our skin can make vitamin D when it's exposed to sunlight, or we can get the nutrient in our diet or as supplements.
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. This amount is slightly higher than the recommendation of 600 IU per day for everyone between the ages of one and 70.
This discrepancy is not surprising. Most experts disagree over what the right amount of vitamin D really is.
Complicating the matter is that the girls in the study all lived in Finland or Denmark, two northern countries with very little sunlight in the winter. And even when it's sunny, the angle of the sun makes the light weaker.
How far north you live matters a lot, said Connie Weaver, spokesperson for the American Society for Nutrition. She said that since most of the US gets more sunshine, base levels of vitamin D are going to be higher.
Wearing sun block and not spending time outside can cut down on the vitamin D we get from the sun. But even on sunny days in the winter, people in northern countries still might not have enough to make vitamin D.
In the study, researchers kept track of vitamin D levels in almost 150 girls in Finland and Denmark for six months, about the length of the winters there. Each of the girls, 11 to 12 years old, was given a supplement containing either five or ten micrograms of vitamin D, or a placebo (a dummy pill).
Because the girls were all getting some vitamin D in their diets, they had a range of levels.
Does your child take vitamin and mineral supplements?