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Joint recommendation on UV radiation and vitamin D

The Federal Office for Radiation Protection (BfS) together with the UV Protection Alliance initiated an interdisciplinary scientific expert discussion on the harmonization of the hitherto conflicting recommendations regarding UV exposure for endogenous vitamin D synthesis. The scientific discussion led to the following joint recommendation:

Recommendation regarding "UV exposure for endogenous vitamin D synthesis"

Joint recommendation of the scientific authorities, expert associations, and professional bodies concerned with radiation protection, health, risk assessment, medical care, and nutritional science

Ultraviolet radiation, on the one hand, stimulates the endogenous vitamin D synthesis in humans. On the other hand, it can cause adverse health effects to the eyes and skin. It is therefore vital to consciously deal with both natural and artificial UV radiation.

Recommendations regarding UV exposure for endogenous vitamin D synthesis are set out as follows:

  • Based on current scientific knowledge, sufficient vitamin D synthesis is achieved when exposing the face, hands, and arms uncovered and without sunscreen to half of the minimum erythemal UV dose (0.5 MED) two to three times a week, i.e. half the time it would usually take unprotected skin to develop a sunburn. In purely mathematical terms, this would correspond to about 12 minutes of exposure to high erythemal UV irradiation (UV index 7), taking skin type II as an example.
  • It is strongly recommended to avoid sunburn.
  • It is strongly recommended to take protective measures against ultraviolet radiation when spending prolonged periods in the sun.
  • The UV index (UVI)1 is recommended as a guide providing the current level of erythemal UV irradiation. Additionally, it also helps to find out when and how to protect yourself against UV exposure. The UV index is a global indicator of the potential maximum UV irradiation occurring within one day. Each single UVI value is linked with UV protection measures recommended for the fair-skinned population.
  • It is strongly recommended to pay special attention to toddlers, children, and adolescents to avoid high UV exposure and sunburns which, particularly during childhood and adolescence, increase the risk of skin cancer during adulthood2.
  • As a matter of principle, never expose babies to direct solar irradiation.
  • It is urgently advised against non-medically controlled high UV exposure (sun or sunbed) for the purpose of endogenous vitamin D synthesis, self-therapy of a vitamin D deficiency, or for tanning. First-time use of a sunbed at younger ages (< 35 years) roughly doubles the risk for malignant melanoma. In Germany, sunbed usage is banned for under-18s.
  • Vitamin D deficiency can only be medically diagnosed and treated. Vitamin D supplementation or medication should be carried out under medical supervision. Babies and toddlers shall be treated with vitamin D supplements up to the second experienced early summer.

1) The current UV-Index and UV forecasts can be found on the web pages of the BfS and of the German National Meteorological Service.
2) Boniol, M., et al., Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis. BMJ, 2012. 345: p. e4757. Boniol, M., et al., Correction. BMJ, 2012. 345: p. e8503.

This recommendation is supported by the following institutions:

(alphabetical order)

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State of 2022.03.29

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