Is Your Child Getting Enough Vitamin D?

If not, she may need a supplement to protect her growing bones

Group of children
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There was a time when kids were highly susceptible to rickets, a disease that causes still-growing bones to become soft and pliable. Children with rickets typically wound up with legs that bowed out to the sides cowboy-style and swollen wrists and ankles. 

Then scientists figured out the most common cause of rickets is a deficiency of vitamin D, the unsung hero of skeletal development: If calcium is the Batman of bone health, vitamin D is the Robin, vital for making sure the body absorbs enough calcium and other minerals key to keeping bones strong and healthy.

Manufacturers began fortifying certain foods with vitamin D, and the incidence of rickets in kids decreased.

In recent years, however, rickets has been on the rise. Some children aren't getting enough vitamin D, putting them at risk not only for rickets but for bone fractures. Here are the most common reasons for vitamin D deficiency in kids, and what you can do to make sure your own child's daily dose doesn't come up short.

D Is for a Deficient Diet

The American Academy of Pediatrics (AAP) recommends babies less than 12 months old get at least 400 international units (IU) of vitamin D per day, and children 1 to 18 get 600 IU of vitamin D daily. The thing is, there aren't a lot of foods, especially kid-friendly ones, that are naturally rich in D. It's plentiful in certain types of fatty fish and fish oils, for instance. In fact, Grandma was on to something for pushing the cod liver oil: Just a tablespoon has more than 1300 IU of vitamin D.

Otherwise, the richest sources of vitamin D are foods that have been fortified with it. Here's a snapshot of how much vitamin D is in foods that are natural sources of vitamin D and some that are fortified with it:

  • Wild salmon (3.5 ounces): 600 to 1000 IU
  • Canned tuna (3.5 ounces): 236 IU
  • Fortified orange juice (1 cup): 137 IU
  • Fortified milk (1 cup): 115-124 IU
  • Fresh shitake mushrooms (3.5 ounces): 100 IU
  • Hard-boiled egg (1 entire egg; the D is in the yolk): 20 IU

S Is for Skimpy Sun Exposure

The other source of vitamin D isn't food at all—it's the sun. Ultraviolet rays stimulate the skin to produce vitamin D. This creates a conundrum, of course, since it's known that direct exposure to sunlight without sun protection can drive up a child's risk of developing skin cancer. That's why the AAP says infants under 6 months should never have direct sun exposure. Older children should be slathered with a generous amount of a broad-spectrum sunscreen with a sun protection factor (SPF) of 15 to 30 before going outside. 

Increased use of sunscreen may be another reason vitamin D deficiency has become more common in kids, so is there really any harm in allowing a child to soak up a few rays in the name of bone health? That's a tough call because no one really knows how much sun exposure is enough to get the benefits. Some vitamin D researchers estimate that just five to 30 minutes of sun exposure to the face, arms, legs, or back between 10 am and 3 pm twice a week is plenty, but you should check with your pediatrician about whether it would be a good idea to let your child go out in the sun unprotected for even short periods of time.

Supplements: To D or Not to D

Whether a child should get extra vitamin D boils down to how much she's getting in her diet. Here's what the AAP advises:  

  • Infants who are being breastfed (even partially) should get 400 IU a day of vitamin D starting within a few days after birth.

  • All infants who aren't nursing and aren't consuming 32 ounces of vitamin D-fortified formula need to be supplemented with 400 IU of vitamin D a day. 

  • Older babies who aren't consuming 32 ounces per day of vitamin D-fortified milk should get supplements of D. 

  • Children age 1 and up who don't get 600 IU of vitamin D per day in their diets should receive a supplement containing that amount. For kids who can't tolerate cow's milk, many brands of almond and soy milk are now fortified with vitamin D. Some brands of yogurt have added vitamin D as well, so consider that when estimating how much your child may be taking in.

  • Children with an increased risk of vitamin D deficiency, such as those taking certain medications and with chronic diseases such as cystic fibrosis, may need higher doses of vitamin D.

If you and your pediatrician decide your child should be getting a vitamin D supplement, there are plenty of kid-friendly options. For babies and toddlers there are vitamin drops. Chewable vitamins are fine for kids 3 and over. And of course, once a child is old enough to swallow pills, she can get her D in that form. 

Sources:

American Academy of Pediatrics. Clinical Report. "Optimizing Bone Health in Children and Adolescents Pediatrics," Pediatrics,  Oct 2014, 134 (4) e1229-e1243.

American Academy of Pediatrics. Policy Statement. "Ultraviolet Radiation: A Hazard to Children and Adolescents." Pediatrics, Mar 2011, 127 (3) 588-597

National Institutes of Health Office of Dietary Supplements. Fact Sheet for Health Professionals. "Vitamin D."

Thacher TD, Fischer PR, Tebben PJ, et al. "Increasing incidence of nutritional rickets: a population-based study in Olmstead County, Minnesota." Mayo Clin Proc. 2013;88:176-183.

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