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Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?
1Department of Dermatological Sciences, Institute of Cellular Medicine, University of Newcastle, Newcastle Upon Tyne, UK. b.l.diffey@ncl.ac.uk
Background/Purpose:
The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice.
Methods:
The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight.
Results:
It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health.
Conclusions:
Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status.
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