Tanning beds may be associated with vitamin D toxicity, according to an observation being published in Annals of Internal Medicine.

The authors describe the case of a 26-year-old white woman who was referred to the endocrinology clinic for asymptomatic vitamin D toxicity. The patient did not excessively consume milk or take over-the-counter vitamin D supplements, and reported minimal sun exposure. However, the patient admitted to using a tanning bed a minimum of three times a week for at least six months. The clinicians advised the patient to stop using the tanning bed since another cause of her elevated vitamin D levels could not be identified. One month later, the patient's serum vitamin D levels had decreased.

The authors observed that tanning beds could be an alternative source of vitamin D for deficient patients that cannot get adequate vitamin D from oral sources. However, the risks for skin cancer would have to be weighed against the benefits of increased vitamin D.

Enough Is Enough, B. Frei, B.N. Ames, J.B. Blumberg, and W.C. Willett, Annals of Internal Medicine, DOI: 10.7326/L14-5011, published 2 June 2014.