Sun beds and cod liver oil as vitamin D sources
The objective of this study was to (1) to determine the contribution of moderate sun bed exposure to serum 25(OH)D3 levels; (2) to estimate the decay time of a high 25(OH)D3 level obtained by sun bed exposure; and (3) to evaluate if the recommended ingestion of vitamin D is sufficient to maintain the 25(OH)D3 concentration obtained by sun bed exposure.Ten volunteers (20–35 y.o.), skin type I and II, living in Olso, Norway were whole body exposed twice per week to the radiation of a commercial and approved sun bed (Life Sun S 100 W, Wolff System), starting with 0.5 MED (minimal erythema dose) and escalating to up to 1 MED per exposure for 4 weeks. After that, half of the volunteers were given a daily supplement of 200 IU vitamin D in the form of cod liver oil capsules, while the other half of the persons received no supplements.Erythema did not occurr at any time and a slight pigmentation was seen in most of the volunteers after the sun bed exposures. Serum level of 25(OH)D3 increased by about 40% on the average. The initial serum 25(OH)D3 level was different among the volunteers (40–100 nmol/L). Within eight weeks after the last exposure the 25(OH)D3 level decreased to the initial value in all volunteers irrespective of vitamin D supplementation or not.
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 91, Issues 2–3, 29 May 2008, Pages 125–131