The first subject was a 49-year-old woman with 50 cm of the bowel remaining after massive small bowel and partial colonic resection secondary to mesenteric ischemia. We obtained Emory University IRB approval to study the effect of the Sperti Del Sol sunlamp (Cresent Springs, KY, USA) in two SBS subjects with chronic, severe diarrhea and vitamin D insufficiency, who both had failed oral courses of vitamin D therapy to improve vitamin D status. Based on these data, we developed a protocol to expose patients to UVB light via the tanning machine for up to 10 min at a distance of 14 inches.
These data provided necessary preclinical data to proceed with our pilot study to evaluate the use of the portable tanning machine in CF and SBS patients with malabsorption. Control ampules that had not been exposed to the tanning device did not demonstrate detectable pre-vitamin D 3. At several distances and times, from 0.5% to 5.0% of pre-vitamin D 3 could be detected in the ampules. We determined that the portable tanning machine could effectively convert 7-DHC to pre-vitamin D 3 ( Fig. We determined the resultant amount of vitamin D 3 by standard high-performance liquid chromatography (HPLC) methods, as described by Holick et al. We exposed ampules containing a known quantity of 7-DHC to the machine at several distances and times to determine the quantity of pre-vitamin D conversion from 7-DHC. Ultraviolet spectrum output of the Sperti Del Sol sunlamp used in the study. In the current study, we sought to evaluate whether a commercially available portable desktop tanning machine could improve vitamin D status in patients with SBS and CF, disorders characterized by chronic malabsorption of fat-soluble vitamins. Koutkia et al ( 1) successfully treated vitamin D deficiency, and associated musculoskeletal pains in a subject with SBS with the use of an indoor tanning bed. Cross-sectional studies have demonstrated that subjects who use an indoor tanning bed at least once a week have higher 25(OH)D levels than control subjects, which correlates with a higher bone mineral density (BMD) ( 13).
Studies evaluating indoor tanning beds have demonstrated that 25(OH)D levels can be raised after exposure to lamps that emit UVB ( 14). Indoor tanning machines emit the same spectrum UVB radiation as sunlight ( 13).
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Despite 50 000 IU of ergocalciferol once a week for a total of 16 weeks in vitamin D-deficient CF patients, all of the patients remained vitamin D deficient ( 10).īecause patients with fat malabsorption syndromes cannot efficiently absorb vitamin D from the diet, an alternative method to raise vitamin D status, especially during the winter months where vitamin D cannot be made ( 11), would be by exposing the skin to UVB produced by a device to produce vitamin D 3 cutaneously ( 1, 12). Current guidelines in CF patients to treat vitamin D deficiency with weekly high-dose ergocalciferol (vitamin D 2) have been ineffective ( 8– 10). CF subjects absorb approximately 50% less vitamin D compared with what normal subjects absorb, depending on the degree of exocrine insufficiency ( 7). CF patients have inefficient vitamin D absorption due to pancreatic exocrine insufficiency resulting in malabsorption of fat-soluble vitamins, including vitamin D. SBS patients have been given high-dose oral vitamin D supplementation without an improvement in vitamin D status due to poor intestinal absorption of vitamin D ( 1, 5, 6). However, patients with malabsorption as in short-bowel syndrome (SBS) and cystic fibrosis (CF) are not able to absorb vitamin D efficiently and thus have a high prevalence of vitamin D deficiency, leading to osteomalacia and osteoporosis. Treatment of vitamin D deficiency in most healthy individuals is accomplished by giving vitamin D 2 (ergocalciferol) 50 000 IU once or twice a week for several weeks ( 4). Circulating 25(OH)D 3 is then converted to 1,25-dihydroxyvitamin D 3 by the kidney 1-α-hydroxylase to act as a steroid hormone to increase the efficiency of calcium absorption primarily in the duodenum to maintain proper serum calcium levels for skeletal health and other cellular signaling processes ( 3). After production in the skin, vitamin D 3 is converted to the major circulating form of vitamin D, 25-hydroxyvitamin D 3 (25(OH)D 3).
Vitamin D 3 (cholecalciferol) is the form of vitamin D that can be produced endogenously in the skin following ultraviolet B (UVB) radiation ( 3). Vitamin D (vitamin D 2 or D 3) absorption from the diet occurs primarily in the duodenum and jejunum ( 1, 2). Vitamin D can either be ingested from the diet (vitamin D 2 or D 3) or produced in the skin (D 3). Vitamin D is an important nutrient for intestinal calcium absorption for optimal skeletal health.
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