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The High Prevalence of Vitamin D Insufficiency across Australian Populations Is Only Partly Explained by Season and Latitude

Citation

Van der Mei, IAF and Ponsonby, AL and Engelsen, O and Pasco, JA and McGrath, JJ and Eyles, DW and Blizzard, CL and Dwyer, T and Lucas, R and Jones, G, The High Prevalence of Vitamin D Insufficiency across Australian Populations Is Only Partly Explained by Season and Latitude, Environmental Health Perspectives, 115, (8) pp. 1132-1139. ISSN 0091-6765 (2007) [Refereed Article]

DOI: doi:10.1289/ehp.9937

Abstract

Background: Inadequate sun exposure and dietary vitamin D intake can result in vitamin D insufficiency. However, limited data are available on actual vitamin D status and predictors in healthy individuals in different regions and by season. Methods: We compared vitamin D status [25-hydroxyvitamin D; 25(OH)D] in people < 60 years of age using data from cross-sectional studies of three regions across Australia: southeast Queensland (27°S; 167 females and 211 males), Geelong region (38°S; 561 females), and Tasmania (43°S; 432 females and 298 males). Results: The prevalence of vitamin D insufficiency (≤ 50 nmol/L) in women in winter/spring was 40.5% in southeast Queensland, 37.4% in the Geelong region, and 67.3% in Tasmania. Season, simulated maximum daily duration of vitamin D synthesis, and vitamin D effective daily dose each explained around 14% of the variation in 25(OH)D. Although latitude explained only 3.9% of the variation, a decrease in average 25(OH)D of 1.0 (95% confidence interval, 0.7-1.3) nmol/L for every degree increase in latitude may be clinically relevant. In some months, we found a high insufficiency or even deficiency when sun exposure protection would be recommended on the basis of the simulated ultraviolet index. Conclusion: Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully-prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.

Item Details

Item Type:Refereed Article
Research Division:Medical and Health Sciences
Research Group:Public Health and Health Services
Research Field:Epidemiology
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Nervous System and Disorders
Author:Van der Mei, IAF (Associate Professor Ingrid van der Mei)
Author:Ponsonby, AL (Professor Anne Ponsonby)
Author:Blizzard, CL (Professor Leigh Blizzard)
Author:Dwyer, T (Professor Terry Dwyer)
Author:Jones, G (Professor Graeme Jones)
ID Code:47508
Year Published:2007
Web of Science® Times Cited:154
Deposited By:Menzies Institute for Medical Research
Deposited On:2007-08-01
Last Modified:2009-09-10
Downloads:0

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