Heliotherapy and Vitamin D

Thanks for the wonderful and very informational site. You have posted some great info on heliotherapy. This is something that I have become a big advocate of after

1) optimizing my vitamin D level through brief periods of mid-day sun exposure and supplementation over the past few years resulting in much improved health, and

2) my recent discovery that exposure to the early morning sunlight both energizes me and has a profound effect on my sense of general health and well-being. Only now I am confused about a few things:

-Many past and present practitioners of heliotherapy insist that we should avoid the mid-day sun because of it's potentially damaging effects. Some say that sun exposure before 9:00 and after 4:00 will give us more than enough vitamin D. Yet everything I have read from doctors who specialize in vitamin D, such as Michael Holick, says that only the mid-day sun has enough UVB for our skin to produce vitamin D.

So while the early morning sun makes me feel great, I don't believe I am really getting vitamin D from it. Doesn't at least some of our exposure to the sun have to be at mid-day if we want to produce vitamin D?




But then what are we to make about the fact that much of the heliotherapy literature discourages mid-day sun exposure and says that morning (or early evening) sun exposure is far superior?

-The other side of the coin: Some of the vitamin D experts seem to say that it is actually more dangerous to get your sun exposure in the traditional "safe times" (early morning and late afternoon) because you are exposed to mainly UVA rays. I am pretty sure that Dr. Mercola has published articles on his website expressing this view. (I wonder if this is still a valid viewpoint since MD Anderson Cancer Center recently released a study that showed that the fish studies originally used to indict UVA as the cause of skin cancer were invalid.)

I guess there is just a lot to be figured out yet but I am really interested in your take on these issues.

Jeff