We are all solar powered to some extent.  While we derive our physical energy from food, sun is a critical part of our development and well-being.  Imagine how you feel after a long, gloomy, overcast winter.  Now imagine a child developing their sense of emotional well-being during such a climate.  Humans used to spend virtually all of our days outside when we lived in the wild, and now that we’re industrialized we spend most of it indoors.  Even when we do go outside these days, we’re fully clothed.  Add to this the recommendations from various authorities to avoid sunlight because of the risk of skin cancer.  So our sunlight exposure has undergone a dramatic shift, and we’re only beginning to understand the consequences of this on our health.

Vitamin D is one critical human need that is met by sunlight - it needs to be converted into its active form by the sun’s rays.  It’s most obvious effect is in regulating our calcium metabolism.  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 coming out linking vitamin D deficiency to all sorts of other things:  cancer, autoimmune disease, autism and mental illness, to name a few.

What about vitamin D supplements?  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 often deficient simply because the sun is too low in the sky to be strong enough to make the conversion to vitamin D in our bodies.  So apart from the middle of summer, a supplement is essential.  There are differing opinions about how much is needed, but using the chart below is a good bet for now. 

Some sources, including the vitamin D council, recommend considerably more than this.  They may be right, but until the safety data is fully out I’m just a little nervous recommending high doses.  In patients of mine who get a good amount of sunlight, the doses in the chart above have led to good blood levels.  In patients who get less sunlight exposure or frequently forget their doses, the levels have been just a little bit below where I like to see them.  So just try to remember the supplement every day, and know that it’s very much OK to double up on days when you forget, whether for an infant or an adult.  If you average the above doses, and get some *safe* sun exposure, you will likely be in good shape. 

What about skin cancer?  Skin cancer is a very real risk, and one to take seriously.  However, the fear of skin cancer may have led to more health problems than it has reduced.  Consider how many people have spent less time in the sun, leading to less exercise, worsening mood, and vitamin D deficiency with all of its associated diseases (other cancers, autoimmune diseases, autism?).  Nonetheless, sunburn is incredibly harmful to the skin and should be strictly avoided (for more on this, see my guide below).

It seems like such a Catch-22, you get one kind of cancer with too much sun, and other kinds with too little sun.  Isn’t there a happy medium?  I like to think so. 

Summer tips:

1. Spend as much time outdoors as possible, it’s good for you!
   

2. Learn how much sun your child can tolerate and always proceed cautiously.  Start small, and gradually increase to make sure they don’t burn.  Once you start to recognize how much sun they can tolerate before they start to turn a little red, take note, and also keep track as the summer goes on because once they get some color they will tolerate more sun (and also require more sun to get vitamin D).  There is no set minute amount because it is different for different children.  Almost all kids can tolerate 10-15 minutes, many can tolerate much more.
   

3. During the “sunshine gathering” part of their outdoors time, have as much skin exposed to the sun as possible, just do it for less time.  More surface area exposed means less sun needed per square inch to produce the same amount of vitamin D for the body.  This means less burning, more vitamin D.  Smart, huh?
   

4. After your child has been in the sun a bit but before the danger of burning comes, cover them with clothing and/or shade.  Apply sunblock only on the parts that can’t be covered, and make sure to use a gentle, fragrance-free variety (always check the 2010 sunscreen guide from the cosmetics database before purchase).  Do not apply sunblock until your child has had a little sun exposure, as it will completely block their vitamin D production.  Let them get some sun first, then apply it if they will continue being outside for a long time.  Just don’t forget because we don’t want them to burn.
   

5. 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.  Also consider the supplement in summer for red heads because they are so sensitive to the sun and may not be able to get enough vitamin D before burning.
   

Spring and Fall tips:

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

2. Your child can likely spend more time in the sun during these times without burning, so you can likely increase their “allotment” and decrease their sunblock usage.
   

3. Take your vitamin D supplement, even when the sun is shining.  It is so low in the sky during these seasons that there may not be enough to get your vitamin D up where it needs to be. 
   

Winter tips:

1. 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.
   

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

3. Some people may use tanning beds, which likely will give you some vitamin D, but those things just make me nervous.
   

4. Take a winter trip to Caribbean!  And while you’re at it, take your pediatrician along with you...