The effect of ultraviolet radiation from a novel portable fluorescent lamp on serum 25‐hydroxyvitamin D 3 levels in healthy adults with F itzpatrick skin types II and III

Summary Background/Purpose Ultraviolet ( UV ) B irradiation may provide a safe and effective method to treat vitamin D deficiency. The objective of this study was to assess the effectiveness of a novel S perti D / UV ‐ F luorescent lamp in converting 7‐dehydrocholesterol (7‐ DHC ) to previtamin D 3 in vitro and in raising serum 25‐hydroxyvitamin D 3 [25( OH ) D 3 ] in healthy adults. Methods The lamp was assessed in vitro using a 7‐ DHC solution and a human skin sample. In a prospective cohort study, five healthy adults with skin types II and III were exposed to a 0.75 minimal erythemal dose of UV radiation over ∼9% of body surface area three times a week for 4 weeks. The main outcomes were percentage of conversion from 7‐ DHC to previtamin D 3 in vitro and changes in serum 25( OH ) D 3 after irradiation in vivo . Results A dose response between UV irradiation time and conversion of 7‐ DHC to previtamin D 3 was seen in the 7‐ DHC solution and surgically obtained human skin. The subjects had a significant increase in mean 25( OH ) D 3 from 18.4 ± 8.2 to 27.3 ± 7.6 ng/ml ( P  < 0.001) after 4 weeks of irradiation. No adverse events occurred. Conclusion The S perti D / UV ‐ F luorescent lamp is effective in converting 7‐ DHC to previtamin D 3 in vitro and in raising serum 25( OH ) D 3 in healthy adults.