Last week, the US Food and Drug Adminisitration ordered tanning bed manufacturers to post warnings on their products that they should not be used by teens under the age of 18, citing concerns about skin burns and increased risks of melanoma, the deadliest type of skin cancer. But there's apparently another danger that's been associated with excessive use of tanning salons: vitamin D toxicity.
In a case report published Monday in the Annals of Internal Medicine, two physicians from Saint Vincent Hospital in Worcester described a 26-year-old woman who they treated for excessively high vitamin D levels detected during a routine blood test. At first they couldn't pinpoint the cause since she didn't take vitamin D supplements and wasn't a big milk drinker. She did, however, go to tanning salon at least three times a week for six months. The ultraviolet radiation from the UV lamps caused her skin to produce vitamin D in excessive amounts to the point that she had a dangerously high level.
Dangerously high vitamin D levels, called hypervitaminosis D, can damage bones, joint tissue, and kidneys over time. It's also associated with a wide range of symptoms, including vomiting, constipation, dehydration, fatigue, and muscle weakness.
"Other such cases have not been reported to our knowledge," wrote the report authors, "and we alert clinicians that patients who use tanning beds may have elevated vitamin D levels."