Making Sure Your Child Gets Enough Vitamin D

During the past five years, the number of children with a vitamin D deficiency has increased by more than 200 percent.

When you were a kid, getting enough vitamin D wasn’t often an issue. If you weren’t in school, you were running around outside. You were exposed to the sunlight, and that was enough to power up your body’s vitamin D. And your parents? They probably endured a spoonful of cod liver oil every night to cover their needs.

But that’s not the case for today’s kids. During the past five years, the number of children with a vitamin D deficiency has increased by more than 200 percent, according to a study by the United Kingdom-based public-awareness campaign Vitamin D Mission.

The lack of vitamin D could be because kids aren’t going outside as much, or because of the rise in the use of sunscreen, which is, naturally, very important for its own reasons. But it leaves today’s parents wondering: Is my child getting enough?

Vitamin D Primer

“Vitamin D isn’t actually a vitamin,” explains Maria Kennedy, a dietitian and nutritionist in Cary. “It’s actually a hormone.” Vitamin D, in other words, isn’t the end game — it’s a starting player that makes things happen in our bodies.

Scientists believe it works like this: Skin contains a substance called provitamin D. When exposed to sunlight, provitamin D begins to change into vitamin D. But then it has to be “activated,” so it travels to the liver, where it undergoes a chemical change. After that, it takes a trip through the bloodstream to the kidneys, where it goes through another change to become the active form our bodies can use.

“Vitamin D is most important for good bone health,” Kennedy says. “It helps your bones absorb calcium. So, when kids weren’t getting enough sunlight, they’d become vitamin D deficient. They’d end up with a condition called rickets, where their bones became soft and weak.”

Vitamin D goes to work doing other things, too. Research shows it boosts the immune and nervous systems, and may even help battle diseases like cancer, cardiovascular disease and multiple sclerosis.

So, how can kids get their vitamin D?

“Mainly from the sun,” Kennedy says. “You can’t get vitamin D from too many foods, but it’s mostly in fatty fish. And there aren’t a lot of kids who readily eat a lot of fatty fish!” It’s also in fortified milk, but Kennedy suggests choosing wisely. “Because it needs to bind to a fat to work, you should use at least 1 percent milk. Skim milk won’t have the fat vitamin D really needs to work efficiently.”

How Much Do Kids Need?

The good news is, it doesn’t take a lot of effort for kids to get the vitamin D they need. Laura Reavis, a clinical dietitian for Cone Health Nutrition and Diabetes Management Center in Greensboro, says infants up to 12 months old need 400 IU (international units, the standard for measurement) daily. “If they’re formula-fed, it’s most likely fortified with the correct amount of vitamin D,” she says, but check the label if you want to be sure. If your baby is nursing, you’ll want to give him a supplement, because it’s not present in breast milk. For kids older than age 1 — and adults up to age 70 — the recommended daily allowance is 600 IU.

“Vitamin D is really most important for kids during periods of rapid growth,” Reavis says. “So, that first year when infants are growing rapidly, it’s important. Then again during the adolescent growth spurt, you want to be sure your child is getting enough.”

If your child is getting her vitamin D from the sun, there’s no need for her to go outside and stand in the middle of the yard for several hours. The ultraviolet radiation waves known as UVB start vitamin D formation, and those waves shine down best around noon. “Exposure for about 20 minutes at noon without sunscreen is enough to make vitamin D and store it,” Reavis says.

Here’s some really cool news: Human bodies can store vitamin D, so if children spend time outside during the summer, Reavis says, typically enough vitamin D will be stored in their fat cells to last them through winter.

What You Can Do

“It’s really not terribly difficult to make sure kids are getting enough vitamin D,” says Dr. Marty Baker, a pediatrician with Carolinas Healthcare in Charlotte. If you have an infant who’s on formula, check the label to see if she’s getting enough. And if you have an infant who’s nursing, talk to her doctor about providing a supplement in a liquid dropper.

But follow the guidelines closely. The Food and Drug Administration cautions parents to only use the dropper that comes with the bottle of vitamin D to avoid toxicity. “And sometimes people think, ‘If one drop is good, 10 would be better,’” Baker says. That’s not the case with vitamin D, since it’s not water-soluble and it’s possible to overdose.

“There’s overload on the kidneys,” Baker explains. “So if it says five drops, do five drops. Not 50 or 15.”

If you’re concerned about your child going outside without sunscreen, it’s not an all-or-nothing scenario.

“If sunscreen were perfect, it would protect us from skin cancer while allowing us to get our vitamin D,” Baker says. Since that’s not the case, apply sunscreen to protect your child’s skin, but be sure he gets outside often to maximize the chances he’ll have enough exposure. Remember, it doesn’t take hours to store up on vitamin D — even several minutes every day is sufficient.

It’s not easy to tell if your child is vitamin D deficient, but if he has pain in his legs or knees, or if he’s getting sick more often, that may be an indication, Reavis says.

If you’re still unsure, Kennedy offers this advice: “If you’ve got a child who doesn’t spend time outside and who doesn’t drink fortified milk, ask the doctor to just have a blood test done,” she says. “It’s simple, it’s quick, and why worry about giving your kid extra vitamin D if they’re already getting what they need naturally?”

Kathleen M. Reilly is a writer and mom in the Triangle. Visit her online at