Reply to MA Weinstock and D Lazovich

Boston University School of Medicine
715 Albany Street, M-1013
Boston, MA 02118-2394
E-mail: mfholick{at}bu.edu

Dear Sir:

It is remarkable that some persons in the dermatology community, including Weinstock and Lazovich, are oblivious to the multitude of publications that have clearly shown vitamin D deficiency to be epidemic in the US population (1–4). The major reason for this is that most children and adults are unable to satisfy their vitamin D requirement from dietary sources (5). Sensible sun exposure is the major source of vitamin D for both children and adults (6). The suggestion that there may have been bias by our failure to account for differences between tanners and nontanners, which may have led to spuriously low concentrations of vitamin D in nontanners, is unfounded. However, because Weinstock and Lazovich apparently consider this to be important, we observed that 40% of the control group was vitamin D deficient at the end of the winter. This observation is consistent with what was previously published by us and others regarding the prevalence of vitamin D deficiency in the adult population in Boston. No statistically significant difference in the use of multivitamins was observed between tanners and nontanners (40% compared with 54%, respectively). When we compared only white nontanners with white tanners, the mean (±SEM) 25-hydroxyvitamin [25(OH)D] concentration was 26.9 ± 2.0 ng/mL in the nontanners and 48.5 ± 3.0 ng/mL in the tanners (P < 0.0001).

Most tanning beds in the United States use lamps that emit between 2% and 5% ultraviolet (UV) B radiation. This is the reason why most subjects who frequented a tanning salon had robust concentrations of 25(OH)D and why 25(OH)D concentrations did not increase in one of the subjects, ie, the subject may have been exposed to a tanning bed that emitted only UVA radiation. We and other investigators previously reported that UVB-emitting lamp sources are very effective at producing vitamin D₃ in the skin and increasing blood concentrations of 25(OH)D (7–9).

One million adults frequent a tanning salon daily in the United States (10) for a variety of reasons, one of which is that it makes them feel better about themselves. Although we do not advocate tanning nor do we advocate frequenting a tanning salon for the sole purpose of enhancing vitamin D status, one of the benefits that tanners obtain from their activity is that they have healthy concentrations of 25(OH)D. Because vitamin D deficiency has been linked to an increased risk of many common deadly cancers, autoimmune diseases, and cardiovascular disease, tanners may benefit from their tanning experience by decreasing their risk of many serious chronic diseases (1). Patients with vitamin D deficiency are encouraged to take pharmacologic doses of vitamin D. Typically, these patients receive 50 000 units of vitamin D once a week for 8 wk and then once every 2 wk to maintain a healthy vitamin D status (11). However, there are more than a million children and adults with various intestinal fat malabsorption syndromes who are unable to obtain their vitamin D requirement from dietary or supplemental oral sources (12). These patients clearly benefit from sensible exposure to sunlight or a lamp source that emits UVB radiation (7).

The New Zealand Bone and Mineral Society and the Australian College of Dermatologists and the Cancer Council of Australia recommend that balance is required between avoiding an increased risk of skin cancer and achieving enough UV radiation to maintain adequate vitamin D concentrations. This sensible recommendation should serve as a model for the American Academy of Dermatology, which advocates abstinence from all sun exposure. Vitamin D deficiency is a major health problem in the United States. The American Academy of Dermatology's recommendation that no one should ever be exposed to direct sunlight is putting the American public at great health risk.

ACKNOWLEDGMENTS

MFH's laboratory received a nonrestricted gift from the nonprofit UV Foundation to support research on the biologic effects of ultraviolet radiation on human health. MFH has not received any compensation from the UV Foundation as a consultant nor has he ever received financial compensation from the Indoor Tanning Association. VT had no conflict of interest.

REFERENCES

1. Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr 2004;80(suppl):1678S–88S.
2. Gordon CM, Kerrin C, DePeter KC, Feldman HA, Estherann G, Emans SJ. Prevalance of vitamin D deficiency among healthy adolescents. Arch Pediatr Adolesc Med 2004;158:531–7.
3. Thomas KK, Lloyd-Jones DH, Thadhani RI, et al. Hypovitaminosis D in medical inpatients. N Engl J Med 1998;338:777–83.
4. Vieth R, Cole DE, Hawker GA, Trang HM, Rubin LA. Wintertime vitamin D insufficiency is common in young Canadian women and their vitamin D intake does not prevent it. Eur J Clin Nutr 2001;55:1091–7.
5. Moore C, Murphy MM, Keast DR, Holick MF. Vitamin D intake in the United States. J Am Diet Assoc 2004;151:190–5.
6. Holick MF. Vitamin D. The underappreciated D-lightful hormone that is important for skeletal and cellular health. Curr Opin Endocrinol Diabetes 2002;9:87–98.
7. Koutkia P, Lu Z, Chen TC, Holick MF. Treatment of vitamin D deficiency due to Crohn's disease with tanning bed ultraviolet B radiation. Gastroenterology 2001;121:1485–8.
8. Chel VGM, Ooms ME, Popp-Snijders C, et al. Ultraviolet irradiation corrects vitamin D deficiency and suppresses secondary hyperparathyroidism in the elderly. J Bone Miner Res 1998;13:1238–42.
9. Chuck A, Todd J, Diffey B. Subliminal ultraviolet-B irradiation for the prevention of vitamin D deficiency in the elderly: a feasibility study. Photochem Photoimmun Photomed 2001;17:168–71.
10. Levy JA. Potential tanning market in the United States. Tanning Trends Magazine 1997 Sept:46.
11. Malabanan AO, Veronikis IE, Holick MF. Redefining vitamin D insufficiency. Lancet 1998;351:805–6.
12. Lo C, Paris P, Clemens TL, Nolan J, Holick MF. Vitamin D absorption in healthy subjects and in patients with intestinal malabsorption syndromes. Am J Clin Nutr 1985;42:644–9.