Many teens, especially black teens, aren't getting enough vitamin D, say researchers, a deficiency that could lead to rickets (a bone-softening disease that causes severe bowing of the legs in growing children), and increase the risk of developing chronic diseases such as heart disease, diabetes, immune system problems, and inflammatory diseases.
The researchers found that 14% of the teens studied were lacking in vitamin D, with black teens 20 times more likely to be deficient than white teens (approximately half were deficient). Compared with the 25% of teens with the highest blood levels of vitamin D, the 25% of teens with the lowest vitamin D levels were:
- almost four times more likely to have risk factors for diabetes and heart disease
- more than twice as likely to be at risk for high blood sugar and high blood pressure
The risk was more than double for girls, and overweight teens had almost twice the risk of deficiency compared with normal-weight adolescents.
Various factors can interfere with the body's vitamin D production, including diet, sun exposure, and skin color — the more skin pigment someone has, the less efficiently the body can make vitamin D.
The main dietary source of vitamin D is milk, but most teens don't drink enough of it and are unlikely to improve their diets or take vitamin D supplements; therefore, more foods need to be fortified with it, the researchers say. They also recommend that teens have their vitamin D level checked during regular physical exams.
Also recommended: safe sun exposure (about 30 minutes a day) because the most efficient way to get vitamin D is through the skin. However, teens (and everybody else) should never get a sunburn and should always wear sunblock.
What This Means to You
Last fall, the American Academy of Pediatrics (AAP) upped its recommended daily intake of 200 IU/day of vitamin D for all infants, children, and teens to 400 IU/day.
Making sure kids get 400 IU of daily vitamin D may help curb infections and fend off health problems like:
- autoimmune diseases (like diabetes, thyroid disorders, celiac disease, etc.)
Kids can get vitamin D from fortified foods, fish, and egg yolks but most don't get enough of it from food alone. And although the body also makes vitamin D when the skin is exposed to sunlight, it can be hard to gauge just how much sunshine is safe and effective for an individual child.
Here are some ways to make sure kids get enough vitamin D:
- Incorporate vitamin-D-rich foods into your family's diet — eggs and fortified foods like dairy products, cow's milk, soy milk, rice milk, cereals, and bread. Look for the vitamin D content on the nutrition label.
- Ask your doctor how much fish is OK if you have young kids. Although fish boasts vitamin D, some kinds may contain too much mercury — like shark, swordfish, king mackerel, tilefish, tuna steak, and canned albacore tuna. It's wise to eat no more than a serving or two a week of lower-mercury seafood options (like catfish, pollock, salmon, shrimp, clams, and tilapia).
- Get the kids outside to help their bodies produce vitamin D from sun exposure. Just make sure to apply a broad-spectrum sunscreen (which protects against both UVA and UVB rays), even on cloudy days. But keep young babies out of the sun — direct sunlight is not safe or recommended for infants under 6 months.
Talk to your doctor about your kids' daily intake of vitamin D and what kind of vitamin D supplement they might need as they grow.
Reviewed by: Steven Dowshen, MD
Date reviewed: March 2009
Source: "Implications of a New Definition of Vitamin D Deficiency in a Multiracial US Adolescent Population: The National Health and Nutrition Examination Survey III." Pediatrics, March 2009.