LIVE BLOG: Sunscreen Controversies (and so-called Vitamin D Deficiency”) “
In this live blog from the SDPA Summer Conference in St. Louis, Dr. James Spencer educates us on the real truth behind “vitamin D deficiency,” and gives pearls of wisdom on sunscreen in the USA.
In terms of vitamin D, keep in mind that the term “deficiency” used to refer to an RDA of under 15 ng/ml. Dr. Hollick and his vendetta against vitamin D deficiency is essentially single-handledly responsible for some labs now citing 32 ng/ml as “normal.”
It’s important to remember that there is no longer agreement on what is actually a “normal” level for vitamin D deficiency. Depending on what lab you use, your patients may or may not be told they are vitamin D deficient, when this may not truly be the case.
What does this mean for Derm? Our patients will be persuaded to go tanning and go out into the sun for more vitamin D, as well as to “not wear sunsblock.”
Question: Can we achieve vitamin D levels from our diet alone?
Answer: Yes, but we may need to adjust and supplement with vitamins.
Historically, it was very easy to achieve 200 IU for Vitamin D through diet (Orange juice, Milk – 1 glass = 100 IU; 1 e.g. yolk = 50 IU; Typical multi-vitamin = 400 IU).
The RDA for Vitamin D last set in 1997 from the Institute of Medicine. They wrote that 20 ng/ml is “the level that is needed for good bone health for practically all individuals” (not 40 ng / ml).
The so-called “studies” which show exceptional evidence that vitamin D demonstrates marked health benefits beyond bone health–esp. those reported by the media–are based on latitude, rather than intervention studies, studies that would not be considered conclusive.
Currently: RDA for Vitamin D has been raised to 600 IU/day; Adults over 70 800.
Max safe intake is 4000 IU/day. Very high levels (above 10,000 IU/day) is known to cause kidney damage. Dr. Hollick advocates 40,000.
Despite theoretic concerns, the health benefits of regular sunscreen use as currently formulated seems safe and advisable.
Do you know how SPF is measured?
It’s based on the time to sunburn! It’s the ratio of protected to unprotected.
+ Did you know: The AAD has raised SPF standard from 15 to 30 SPF.
Why? In the lab they do 2mg/sq.cm. People put on much less in real life. 1mg-2.5. 1-1.5 less than what they should put on. They are putting on 7.5 SPF, essentially.
+ Keep in mind that our UVA blockers are not very good (in sunscreen).
+ Also: there is no such thing as a waterproof sunscreen.
[image by Bradley Stemke]