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Limited exposure to ambient ultraviolet radiation and 25‐hydroxyvitamin D levels: a systematic review
Author(s) -
Rice S.A.,
Carpenter M.,
Fityan A.,
Vearncombe L.M.,
ArdernJones M.,
Jackson A.A.,
Cooper C.,
Baird J.,
Healy E.
Publication year - 2015
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/bjd.13575
Subject(s) - vitamin d and neurology , ultraviolet radiation , medicine , ultraviolet a , ultraviolet , dermatology , chemistry , radiochemistry , materials science , optoelectronics
Summary Vitamin D can be synthesized following exposure to ultraviolet radiation ( UVR ), ingested in the diet or provided through oral supplementation. The medical literature frequently states that humans obtain most of their vitamin D from sunshine and that UVR exposure is essential to maintain vitamin D levels. A systematic review was conducted to determine the requirement for UVR in maintaining adequate (> 50 nmol L −1 ) serum 25‐hydroxyvitamin D [25( OH )D] levels. Studies reporting serum 25( OH )D during situations of negligible UVR exposure were sought. Forty‐one studies (from a search yielding 42 698 articles) with a total of 4211 healthy adults met the inclusion criteria, providing 56 datasets from different population groups. Over 50% of subjects had > 50 nmol L −1 25( OH )D in 10 of 19 datasets reporting winter levels in areas with limited UVR . In addition, > 50% of subjects had adequate 25( OH )D levels in four of 12 datasets from polar regions during periods of negligible UVR , one of nine datasets documenting clothing‐related minimal UVR and two of eight datasets detailing employment‐related minimal UVR . The data demonstrate that many adults maintain adequate serum vitamin D levels despite negligible UVR exposure for several months. However, we acknowledge that preceding UVR exposure leading to vitamin D storage and delayed release may account for this maintenance of adequate serum vitamin D levels. There remains a need for further research on whether UVR exposure is required for longer‐term maintenance of adequate vitamin D levels.