A really interesting study revealed something most of us intuitively thought was true: if you drink your milk, your bones are stronger and the less likely you’ll be to break a bone.
Milk consumption in the US has declined a lot over the last few decades at the same time girls’ participation in sports has increased. Broken bones in girls have been on the rise too but it wasn’t immediately clear if it was due to increased risk taking behavior in sports or weaker bones. It’s probably a bit of both. The recent study though controlled for many of the other factors that could contribute to stress fracture risk and found that girls who had the most Vitamin D in their diet were 52 percent less likely to have a stress fracture than girls with the lowest consumption. Ingestion of dairy per se and even calcium were not contributors to the decreased risk because many of the preferred dairy products including cheese and yogurt are not fortified with Vitamin D. Most milk available at the grocery store is enriched though so drinking 8-10 ounces of milk (a small glass) three times a day will give most girls the Vitamin D they need to ensure good bone health.
Lots of kids don’t seem to like milk as they get older and some will have stomach aches or diarrhea if they have too much so for those children, a Vitamin D supplement makes the most sense. Supplements of 1000-1200IU/day are safe and make sense. Keep eating dairy products though! Calcium may not have been shown in this study to be protective but it has other important benefits especially in growing children.