Daily duration of vitamin D synthesis in human skin with relation to latitude, total ozone, altitude, ground cover, aerosols and cloud thickness

Photochem Photobiol. 2005 Nov-Dec;81(6):1287-90. doi: 10.1562/2004-11-19-RN-375.


Vitamin D production in human skin occurs only when incident UV radiation exceeds a certain threshold. From simulations of UV irradiances worldwide and throughout the year, we have studied the dependency of the extent and duration of cutaneous vitamin D production in terms of latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude. For clear atmospheric conditions, no cutaneous vitamin D production occurs at 51 degrees latitude and higher during some periods of the year. At 70 degrees latitude, vitamin D synthesis can be absent for 5 months. Clouds, aerosols and thick ozone events reduce the duration of vitamin D synthesis considerably, and can suppress vitamin D synthesis completely even at the equator. A web page allowing the computation of the duration of cutaneous vitamin D production worldwide throughout the year, for various atmospheric and surface conditions, is available on the Internet at http://zardoz.nilu.no/~olaeng/fastrt/VitD.html and http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez.html. The computational methodology is outlined here.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerosols*
  • Altitude*
  • Computer Simulation
  • Humans
  • Internet
  • Models, Theoretical*
  • Ozone*
  • Skin / metabolism*
  • Skin / radiation effects
  • Time Factors
  • Ultraviolet Rays
  • Vitamin D / biosynthesis*
  • Weather


  • Aerosols
  • Vitamin D
  • Ozone