On the beach
Creative Commons License photo credit: treehouse1977

The summer is almost over and it is back to school time. Hopefully you got a chance to soak up the sun and enjoy some time off with your family. Chances are you were liberal with the sunscreen whenever you went out in the sun. That is definitely the conventional wisdom and there is nothing wrong with it. But did you know that getting some sun without the sunscreen is the best way of building up your child’s vitamin D reserves? Now I am sure you are worried about the damaging effect of too much sun on your child’s tender skin. But it does not take much to get a healthy dose of vitamin D.

I shook my head in disbelief when I read that even in sunny Florida, sub-optimal levels of vitamin D, and even deficiency of vitamin D, are quite common. On a recent discussion about vitamin D on LinkedIn, Diane Batshaw Eisman, MD FAAP wrote:

I am amazed that I find very low levels of Vit D here in Florida. I think we listen to the dermatologists and the natives avoid too much sun and then slather on the sunscreen.

There is some truth to the notion of slathering on the sunscreen because of the strong health advisory and heavy advertising by the makers of sunscreen. There is very little voice to the notion of getting your vitamin D from the sun. After all, who would want to risk advising people to stay out in the sun without sunscreen just to get vitamin D but end up getting melanomas?

Getting vitamin D from the sun appears to be a well kept secret! Experts have even developed a mathematical relationship between the amount of sun exposure and vitamin D. Holick’s rule is well known in the academic circles:

Sun exposure of 1/4 of a minimum erythemal dose (MED) over 1/4 of a body is equivalent to 1000 IU of oral vitamin D3

Minimum erythemal dose is the amount of energy required to produce the first visible sign of redness with clearly defined borders on your skin. In short, this is when you are about to get a burning sensation. The value of MED depends on the skin type – low for very fair skin and high for very dark skin. There are 6 different skin types defined based on the amount of pigment (fair vs. dark) and how easily it burns under the sun. The more popular UV Index is designed based on MED – for example, a type II skin will receive 1 MED within 20 minutes at a UV index of 10. To get a 1/4 of the MED, they would need to be in the sun for only 5 minutes, which means they can get 1000 IU of vitamin D3 in just 5 minutes with their arms and legs exposed without sunscreen! Consider this when the current recommended amount for toddlers is only 400 IU per day.

These calculations are not exact and actual exposure numbers may be different. The point is that it does not take much to get your daily quota of vitamin D3 from the sun. Of course, it is important to use good judgment and common sense not to overexpose the unprotected skin.

We live in a world where the solution to all our problems comes in a pill! For centuries, we have survived by getting this essential nutrient from the sun and diet – in fact, our skin color evolved in response to the amount of available sunlight. In the 21st century, they now want you to believe that sunlight is too dangerous and that you should solve your vitamin D problem by popping a pill each day.

What do you think? Should the public health message about sun and sunscreen change?

©2010 Littlestomaks.com


  1. Jenna

    Yes! I do think it makes sense to educate people about what “safe sun” is. We all know a lot about what “dangerous sun” but there is a line on a continuum where none is also dangerous. At the pool this summer my kids would swim without sunscreen and swimshirts for 20 minutes, then I’d call them up, dry them off, apply sunscreen and have them put on their swim shirts. they hated the interruption from swimming and i got lots of eye rolls from the hubs, but i can also report that none of us experienced colds this summer. i’m a believer in safe sun, and even though it’s a hassle to get the right amout, but not too much, i will teach my family that a little sun is good and to cover up at the right time. thanks for bringing up this important topic.

  2. Anonymous

    Hello Jenna
    Thank you for sharing your experience. Actually, it is not very hard to determine approximately how much sun you should be getting for vitamin D without over exposure. It is related to the skin type and the UV index at that time. I will be posting more about it in future.

  3. Maryann Jacobsen

    I agree that people take the sunscreen too far. Sometimes I don’t even put sunscreen on my kids if they are not in the sun that long or there is some shade. I still give them vitamin D because it’s hard to know if they get enough from the sun. I write about this in the article “health mistakes families make” http://www.zenfamilyhabits.net/2010/08/5-health-mistakes-smart-families-make/

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