Ultraviolet-B radiation increases serum 25-hydroxyvitamin D levels: the effect of UVB dose and skin color

J Am Acad Dermatol. 2007 Oct;57(4):588-93. doi: 10.1016/j.jaad.2007.03.004. Epub 2007 Jul 16.


Background: Ultraviolet (UV)-B light increases vitamin D levels, but the dose response and the effect of skin pigmentation have not been well characterized.

Objective: We sought to define the relationship between UVB exposure and 25-hydroxyvitamin D (25-OH-D) concentrations as a function of skin pigmentation.

Methods: Seventy two participants with various skin tones had 90% of their skin exposed to UVB light (20-80 mJ/cm2) 3 times a week for 4 weeks. Serum 25-OH-D was measured weekly.

Results: Eighty percent of the variation in treatment response was explained by UVB dose and skin tone. Therapeutically important changes in 25-OH-D were achieved with minimal tanning.

Limitations: Four weeks was not long enough to reach a steady state at the higher dose rates.

Conclusions: The response of 25-OH-D levels to UVB light is dependent on skin pigmentation and the amount of UVB given, and useful increases in vitamin D status can be achieved by defined UVB doses small enough to produce only minimal tanning.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Calcifediol / blood*
  • Dose-Response Relationship, Radiation
  • Female
  • Humans
  • Male
  • Middle Aged
  • Skin / metabolism*
  • Skin / radiation effects*
  • Skin Pigmentation / physiology*
  • Skin Pigmentation / radiation effects
  • Ultraviolet Therapy*
  • Vitamin D Deficiency / blood


  • Calcifediol