A Danish dermatology group reported this month that using the amount of sunscreen health officials recommend will completely block vitamin D production — adding to the volume of studies showing that SPF over-use will deprive people of natural vitamin D production.
“When the amount of sunscreen and SPF advised by the World Health Organization is used, vitamin D production may be abolished,” authors from the Bispebierg Hospital Department of Dermatology wrote in the British Journal of Dermatology this month. “Re-evaluation of sun protection strategies could be warranted.”
The group conducted a randomized clinical trial with different sunscreen layer thicknesses. As you might expect, the thicker the sunscreen, the less vitamin D produced.
Smart Tan encourages sunscreen usage only when sunburn is possible — which is, in fact, the only intended usage for the product. The multibillion-dollar over-the-counter skin care industry promotes daily 24/7 usage of sunscreen in daily-use cosmetics even when the sun isn’t shining, which Smart Tan contends is misbranding the product.
As vitamin D levels have plummeted worldwide in the past generation, over-use of sunscreen and/or overzealous sun avoidance is believed by most researchers to be the main reason — except by dermatology groups or groups tied to pharmaceutical sunscreen companies.