All Sun is Harmful?

This is an important post. My title is a little play on words associated with tobacco smoke. We, as health care professionals, are very clear in saying that there is no safe level of tobacco smoke... period. It appears that there is no safe level of unprotected sun exposure either. This is a new message. It is important because as harmful as the sun may be, its creation of Vitamin D is health promoting.

In the past week a statement regarding sun exposure and vitamin D was released by both the American Academy of Dermatology and The National Council on Skin Care Prevention. Both challenge an idea from only three or four years ago that I myself promoted. The old message was that 10 to 15 minutes of sun exposure would provide adequate D without putting the person at risk for skin cancer. That is no longer the last word.


I was also under the impression that sunscreen did not prevent the natural absorption and synthesis of ultraviolet light to vitamin D. I was wrong on that all along. As it is not considered safe to be exposed to any amount of sunlight without protective lotions (spf 15 and up) clothing and sun glasses, other sources of Vitamin D are to be utilized.

There are other risk factors for vitamin D deficiency which include older age, obesity and having dark skin. All of us are encouraged to talk to our physicians about how to get enough vitamin D and physicians are encouraged to study the issue so they can make the recommendations.

It is hard to get Vitamin D solely from your plate unless you are eating foods that have it added to them. Milk is of course the most popular source for the vitamin, as it is fortified. (fat content of milk does NOT effect calcium or D). The USDA nutrient data base does not yet list foods in order of Vitamin D content as it does with other nutrients, however, a project is under way to find those foods and supplements because " Vitamin D is among the highest ranked nutrients of public health significance and is, in part, the subject of recent publications published by the Institute of Medicine, National Academy of Science. " The data gathering is supposed to end this fall. I am very much looking forward to that.

Eggs and fish are other sources of vitamin D.


No matter how the vitamin D arrives, sun, food or supplement it still goes through two changes in the body before becoming usable. In case you are wondering, the process is called hydroxylation and one occurs in the kidney and the other in the liver.


Please note that there is an upper limit on vitamin d intake, meaning there is a level of which toxicity occurs. At this time, some experts, including the ones I respect, do advise at least 1000 IU of Vitamin D-3 for adults with up to 2000 IU as safe. Children under 18 and infants also need vitamin D though the recommendation is 400 IU. It is said that they too can have up to 1000 IU a day. Absolutely discuss any supplementation with your child's pediatrician.


The take home message is this. We must avoid unprotected sun exposure and we must get adequate vitamin D intake. I think that many of us do not take the risk of skin cancer seriously. I DO not and I know better. I think I am a bit like a smoker who rationalizes not quitting by saying, "well I used to smoke 2 packs a day". My rationalization for not always wearing sunscreen or hats or glasses, has been, "Yes, but I used to lay out with motor oil." In both cases, better isn't best. All smoke and all unprotected sun exposure are to be avoided.

Again, the vitamin D supplement that is recommended is called D-3 or cholecalciferol.