Sunbed radiation provokes cutaneous vitamin D synthesis in humans--a randomized controlled trial

Photochem Photobiol. 2008 Nov-Dec;84(6):1487-92. doi: 10.1111/j.1751-1097.2008.00372.x. Epub 2008 May 29.


We wanted to investigate whether the use of sunbeds with sunlamps emitting mainly UVA and only 0.5% or 1.4% UVB will increase the level of serum 25-hydroxyvitamin D (25(OH)D). In a randomized, controlled, open study on healthy, Caucasian females (> 50 years) sunbed radiation was given as follows: four 6-min sunbed sessions (days 0, 2, 4 and 7) and four 12-min sunbed sessions (days 9, 11, 14 and 16 ) with sunlamps emitting 0.5% UVB (n = 20) or with sunlamps emitting 1.4% UVB (n = 15). The controls (n = 21) had no intervention. Serum levels of 25(OH)D were measured on days 0, 9 and 18 in all three groups. The average increase in serum 25(OH)D from day 0 to day 9 was 12 nmol L(-1) (SD 11 nmol L(-1), P = 0.0002) in the 0.5% UVB group and 27 nmol L(-1) (SD 9 nmol L(-1), P < 0.0001) in the 1.4% UVB group. From day 9 to day 18 a further but not significant increase in serum 25(OH)D of 3 nmol L(-1) (SD 9 nmol L(-1), P = 0.2) in the 0.5% UVB group and 0.6 nmol L(-1) (SD 18 nmol L(-1), P = 0.9) in the 1.4% UVB group was seen. No significant changes were found in the control group. Increasing with UVB dose and exposure time, 37-64% of the sunbed sessions resulted in side effects such as erythema or polymorphic light eruption. The results showed that sunbeds emitting 0.5% and 1.4% UVB increased 25(OH)D serum levels. The increases were dose dependent but reached a plateau after few sessions. Sunbed use as vitamin D source is, however, not generally recommendable due to the well-known carcinogenicity and high frequency of acute side effects.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Beds
  • Female
  • Humans
  • Middle Aged
  • Skin / metabolism*
  • Skin / radiation effects*
  • Spectrophotometry
  • Sunbathing*
  • Vitamin D / biosynthesis*
  • Vitamin D / blood


  • Vitamin D