Sunshine and Vitamin D

We are all solar-powered to some extent. While we derive our physical energy from food, sun is an important part of our development and well-being. But it can also increase our risk for skin cancer, and as you'll see here children are the most vulnerable to these effects. So this page will help you enjoy the benefits of sun exposure while minimizing the risks.

What is Vitamin D? This is a vitamin that is activated in our bodies by sunlight. It’s most direct effect is regulating our calcium. Without vitamin D, our bones don’t mineralize well, causing rickets. Rickets sucks. But we are now learning that rickets is just the tip of the iceberg. New research is evaluating what other roles vitamin D deficiency might have in all sorts of other diseases: cancer, autoimmune disease, developmental disorders, asthma, and mental illness to name a few. 

In an ideal world, we would get just the right amount of sunlight, and therefore the right amount of vitamin D. In reality, however, children in Portland (even those who play outside all the time) are typically deficient. During the summer, clothing and sunblock prevent the vitamin D activation from occurring, and during the winter the sun is too far away to be strong enough to make the conversion possible. Therefore, a vitamin D supplement is critical for all infants, children and adults. Opinions differ on exactly how much is needed, so until we develop more specific recommendations, here is a good starting place:

Vitamin D dosing

  • Breastfed infants and toddlers: 400 IU per day

  • Children: 600 IU per day

  • Teenagers and Adults: 800-1,000 IU per day

  • Pregnant/nursing moms: 1,000-2,000 IU per day

Some sources, such as the vitamin D council, recommend considerably more than this. They may be right, but until the safety of doing so is better researched we’re a little nervous recommending high doses, unless their blood test reveals a deficiency. In patients of mine who take their supplements regularly, standard dosing often leads to decent blood levels. In those who frequently forget their doses, however, the levels are often too low. So start with the above chart, and try to remember the supplement every day. Also, know that it’s very much OK to double up on your dose if you forgot to take it the day before, whether for an infant or an adult. Lastly, some families choose to take their supplement only during winter months — this option will be discussed below.

What's the deal with skin cancer? When humans lived in the wild, we were exposed to sun all the time, but we often didn't live long enough for skin cancer to develop. Now that we're living two to three times as long, though, we have to be more careful. Children are the most vulnerable. Their young skin offers less protection against damage, they spend more time outdoors, and because of their young age, any damage to the skin will have decades of time in which to become cancer. While sun exposure can still be a healthy part of childhood in moderation, sun burn appears to be much more damaging and should be avoided at all costs. In fact, a single sunburn in childhood may as much as double a child’s lifetime risk of skin cancer. Burn twice? 4 times the risk. Because risk multiplies, burn just a handful of times in childhood and their risk goes off the charts.

OK, so skin cancer is a very real risk, and one to take quite seriously. However, excessive fear of skin cancer might create other health problems. Consider how spending less time in the sun could lead to less exercise, worsening mood, and vitamin D deficiency with all of its potential consequences, which some believe may even include increased risk of some other cancers. So having a healthy relationship with the sun is important — it’s about finding the right balance.


Finding balance: the guide to summer sun and winter blues.


Summer tips:

  • Spend as much time outdoors as possible, it’s good for you! Here's how to stay safe when you're out there.

  • If you want to gather some vitamin D naturally, follow these tips:

    • Small amounts more frequently are better than large amounts less frequently.

    • Larger surface areas exposed for short amounts of time are better than small surface areas exposed for large amounts of time.

    • Monitor, monitor, monitor. Set a timer. Is setting a timer excessive? Nope! Would you set a timer to avoid burning your turkey? I would argue that kids are at least as important as turkeys...

    • Pay attention to how much sun your child can tolerate and always proceed cautiously.

    • Start small, and gradually increase as summer progresses. As the summer goes on they may get some color and tolerate more sun without burning.

    • There is no set amount of time, it is different for different skin types. 10-15 minutes is usually safe, many can tolerate more as summer progresses.

    • Applying sunblock will block vitamin D production, so apply after a short period of exposure if you want to get some vitamin D first. Just don't forget to time it and monitor them!

  • How to protect against sunburn:

    • Cover your children with clothing and/or shade.

    • Apply sunblock to the parts that can’t be covered, and use a gentle, fragrance-free variety when possible (the sunscreen guide from the cosmetics database is handy).

    • Reapply, reapply, reapply. Frequent reapplications are necessary.

  • Note your child’s skin tone. The highest risk children for skin cancer are red heads, lowest risk are dark-skinned children. This also means that darker-skinned children need to work harder to get vitamin D, and may benefit from vitamin D supplements even in the summer. Red heads will likely need it, too, because they are so sensitive to the sun they can never get enough vitamin D before burning.


Spring and Fall tips:

  • Continue to spend as much time outside as possible, with skin exposure as permitted by weather/temperature.

  • Your child can likely spend more time in the sun during these times without burning, but still be careful about burns, they still happen!

  • Take your vitamin D supplement, even when the sun is shining. It is typically too far away during these seasons to keep up your vitamin D levels.

Winter tips:

  • Continue to spend as much time outdoors as possible. Though there will be no vitamin D production clothing or not, it’s still good to get out there and stay active.

  • Take your vitamin D supplements! Try not to forget, but if you do, remember to double up.

  • While some people use tanning beds, which can give some vitamin D production, we do not recommend them because they are an unnatural source and may increase skin cancer risk.

  • Take a winter trip to Caribbean! Just remember that sudden major sun exposures like tropical trips in winter are risky because your skin hasn't had enough time to gradually adjust to it, so take extra sun precautions. And while you’re at it, take your pediatrician along with you just in case...


Healthy Schedule

  • After birth (within 24 hours)

  • Newborn visit (day 3-5 of age, home visits encouraged)

  • 2 weeks

  • 2 months

  • 4 months

  • 6 months

  • 9 months

  • 12 months

  • 15 months

  • 18 months

  • 24 months

  • 30 months

  • Yearly thereafter