Right after I coated my kid with SPF 70 sunscreen and dropped her off at camp this morning, I picked up the newspaper and read: "Millions of Children in U.S. Found to be Lacking Vitamin D." Sunscreen was listed as a main culprit for the deficiency, which can put children at risk of developing high blood pressure, high blood sugar, heart disease, and weak bones. Yikes! I've been slathering on sunscreen so my pasty-white kid doesn't get skin cancer. But heart disease doesn't sound good, either.
The fact that increasing numbers of American children are lacking in vitamin D isn't new, but this latest report is the first nationwide assessment of D intake among kids, based on federal data. Nine percent of children up to age 21 were found to be seriously deficient in D (defined as less than 15 nanograms per milliliter of blood, a level at which a child might get bone-warping rickets). Another 61 percent, while they had higher blood levels of D (15 to 30 nanograms per milliliter), still had higher blood pressure and lower levels of good cholesterol. Girls, teenagers, and children with darker skin are more likely to be lacking. The main culprits? More time indoors with video games and computers; less milk, which is fortified with vitamin D; and sunscreen.
So I quickly phoned Michal Melamed, senior author of the study and an assistant professor of medicine, epidemiology, and population health at the Albert Einstein College of Medicine in New York. Did I do wrong when I put sunscreen on my child? "I did the same thing this morning," she said. "I have possibly the lightest-skinned boy in the whole world. So if he goes outside for 10 minutes, his face gets all red. We don't send him outside without sunscreen."
But being in the sun is the easiest and safest way to get vitamin D, because the skin makes the prohormone in response to sun exposure. It's impossible to get too much of it this way, unlike the vitamin in supplement form. Melamed recommends 10 to 15 minutes a day in the sun without sunscreen for children who can handle it. "Parents know their children," she says. "If your child is very sun sensitive, obviously you don't want them to get a sunburn."
Since my child falls into that category, I'll be following Melamed's other advice: having her drink milk or orange juice fortified with vitamin D. But a child would have to drink a quart of milk to get the 400 IU currently recommended for children, and that's not happening in my house. So I'll be looking at vitamin D supplements, particularly when winter comes around.
If you're looking to find out more about vitamin D in food, check out my colleague Katie Hobson's report on vitamin D in yogurt. Some yogurts have D, some don't (and it seems to be random). And Deborah Kotz has been following the debate on how much time in the sun a person needs to make vitamin D. She's also written about whether vitamin D is the latest cure-all vitamin, a question that the National Academy of Sciences will be considering Tuesday.