The high prevalence of vitamin D insufficiency across Australian populations is only partly explained by season and latitude
Author(s)
A.F. van der Mei, Ingrid
Ponsonby, Anne-Louise
Engelsen, Ola
A. Pasco, Julie
J. McGrath, John
W. Eyles, Daryl
Blizzard, Leigh
Dwyer, Terence
Lucas, Robyn
Jones, Graeme
Griffith University Author(s)
Year published
2007
Metadata
Show full item recordAbstract
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 (27ӻ 167 females and 211 males), Geelong region (38ӻ 561 females), and Tasmania (43ӻ 432 females and 298 males). Results The prevalence of vitamin D insufficiency (= 50 nmol/L) in women in ...
View more >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 (27ӻ 167 females and 211 males), Geelong region (38ӻ 561 females), and Tasmania (43ӻ 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.
View less >
View more >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 (27ӻ 167 females and 211 males), Geelong region (38ӻ 561 females), and Tasmania (43ӻ 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.
View less >
Journal Title
Environmental Health Perspectives
Volume
115
Issue
8
Subject
Public Health and Health Services not elsewhere classified
Environmental Sciences
Medical and Health Sciences