Treatment of vitamin D deficiency with UV light in patients with malabsorption syndromes: a case series.

BACKGROUND Cystic fibrosis (CF) and short bowel syndrome (SBS) patients are unable to absorb vitamin D from the diet and thus are frequently found to be severely vitamin D deficient. We evaluated whether a commercial portable ultraviolet (UV) indoor tanning lamp that has a spectral output that mimics natural sunlight could raise circulating 25-hydroxyvitamin D [25(OH)D] levels in subjects with CF and SBS. METHODS In initial pilot studies, two SBS subjects came to the outpatient clinic twice weekly for 8 weeks for UV light sessions of 6 min each. In a follow-up study, five CF subjects exposed their lower backs in a seated position to the sunlamp at a distance of 14 cm for 5-10 min depending on the skin type five times a week for 8 weeks. Blood samples for 25(OH)D and parathyroid hormone (PTH) measurements were performed at baseline and at the end of the study. RESULTS In our study, with two SBS subjects, the indoor lamp increased or maintained circulating 25(OH)D levels during the winter months. We increased the UV lamp frequency and found an improved response in the CF patients. Serum 25(OH)D levels in CF subjects at baseline were 21 +/- 3 ng/ml, which increased to 27 +/- 4 ng/ml at the end of 8 weeks (P=0.05). PTH concentration remained largely unchanged in both population groups. CONCLUSION A UV lamp that emits ultraviolet radiation similar to sunlight and thus produces vitamin D(3) in the skin is an excellent alternative for CF, and SBS patients who suffer from vitamin D deficiency due to fat malabsorption, especially during the winter months when natural sunlight is unable to produce vitamin D3 in the skin. This UV lamp is widely available for commercial home use and could potentially be prescribed to patients with CF or SBS.