Question: I recently heard that tanning beds might be safer than previously thought and that they promote health by stimulating vitamin D production. Can you comment?
Answer: The source for your information seems to be a recent ad campaign sponsored by a trade group representing the indoor tanning industry.
In general, advertisements and other information provided by special-interest groups should be taken with a grain of salt.
First, let's get our bearings.
The sun's ultraviolet light consists of UVB and UVA rays. Indoor tanning devices emit primarily UVA rays.
UVA rays are associated with tanning, and UVB rays are associated with sunburn. That's why tanning devices are weighted toward UVA.
UVB affects the skin surface. UVA penetrates the skin. Both types can contribute to premature skin aging, wrinkling and damage.
The tanning industry press release I received said, ”there is no compelling evidence that UV exposure causes melanoma.“
It's true that there's debate over the role played by the sun's UV rays in the development of melanoma, the most serious form of skin cancer.
On the other hand, published evidence indicates that regular exposure to the UV rays of indoor tanning devices increases the risk of melanoma.
Exposure to the UV rays of either natural sunlight or tanning devices raises the risk of squamous cell and basal cell skin cancers.
Some experts think that a higher UVA to UVB ratio (more UVA than UVB), as found in tanning devices, ratchets up skin cancer risk.
The National Institutes of Health states, ”Exposure to sunbeds and sunlamps is known to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in humans, which indicates a causal relationship between exposure to sunbeds and sunlamps and cancer.“
The World Health Organization holds a similar position and says that no one younger than 18 should use a sunbed.
The press release correctly states that exposure to UV light, whether from the sun or a tanning bed, stimulates the production of vitamin D, and that many Americans don't get enough vitamin D.
UVB rays stimulate the skin to produce vitamin D (the ”sunshine vitamin“).
Vitamin D needs can be met with regular, brief periods of unprotected exposure to natural sunlight.
Though tanning beds use mainly UVA, a standard 20-minute session can provide several times the amount of UVB needed for vitamin D production. The extra exposure time is needless because the body stops making vitamin D after adequate amounts are produced.
In any case, a vitamin D supplement can make up for shortfalls in this important vitamin.
Note that UVA rays are associated with drug-photosensitivity reactions and the reawakening of cold sores and fever blisters.
The sun protection factor number on sunscreen labels refers to protection from UVB, which causes sunburn.
The FDA has fielded a new proposal to also rate sunscreens for UVA protection. The rating system uses one to four stars, with four indicating the highest UVA protection.