Too little sun may contribute to deficiency in vitamin D, which is critical for many things, including building healthy bones and preventing heart disease.

By Hollee Actman Becker
May 31, 2017
sunscreen and vitamin D
Credit: Olga Pink/Shutterstock

Summer is finally here, and with it comes the three other big S's: sea, sand, and sunscreen—that latter of which should be a non-negotiable staple for protecting against skin damage. But now there's a new study that suggests there may be a pretty big drawback to repeatedly slathering your kids in the stuff: Turns out, it could lead to vitamin D deficiency.

A bit of background: Vitamin D is nicknamed "the sunshine vitamin" since the sun activates its production in our skin. It's actually a hormone that plays a big role in the body's functions, including cell growth modulation, immune function, and inflammation reduction. It also helps bones absorb calcium, keeping them healthy and strong at every stage of life.

But researchers found that the religious use of sunscreen with SPFs of 15 and higher can interfere with vitamin D absorption. In fact, according to one 2009 study of more than 6,000 American children, about 7 out of 10 kids have low levels of vitamin D, raising their risk of bone and heart disease.

"People are spending less time outside and, when they do go out, they're typically wearing sunscreen, which essentially nullifies the body's ability to produce vitamin D," researcher Kim Pfotenhauer, DO, explained to Science Daily. "While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D."

According to Dr. Pfotenhauer, increasing and maintaining healthy vitamin D levels—in 2010, the Institute of Medicine of the National Academies updated its dietary guidelines to recommend 600 IU of vitamin D daily for people ages 1 to 70—means spending 5 to 30 minutes in the midday sun sans sunscreen twice a week.

"You don't need to go sunbathing at the beach to get the benefits," she explained. "A simple walk with arms and legs exposed is enough for most people."

But New York City dermatologist Doris Day, M.D., a spokesperson for the Skin Cancer Foundation, disagrees. "Most people get more sun than they realize even if they wear sunscreen," she told "Why take a risk from sun exposure when a supplement will provide the same benefits?"

Dr. Pfotenhauer agrees that supplements are a good option. Because while food sources like milk, fortified breakfast cereals, fatty fish, and fish oils are another way for the body to get vitamin D, kids don't always consume enough to get what they need. But supplements, Dr. Pfotenhauer explained, are effective and pose few risks as long as they are taken as directed and you consult your pediatrician beforehand.

The American Academy of Pediatrics and Institute of Medicine recommend a daily intake of 400 IU of vitamin D during the first year of a child's life, and 600 IU for everyone older than 1.

Hollee Actman Becker is a freelance writer, blogger, and mom of two who writes about parenting and pop culture. Check out her website for more, and then follow her on Instagram and Twitter.