Association of vitamin D status with socio-demographic factors in Calgary, Alberta: an ecological study using Census Canada data
BMC Public Health 2013, 13:316 doi:10.1186/1471-2458-13-316; Published: 8 April 2013
Christopher Naugler, Jianguo Zhang, Dan Henne, Paul Woods and Brenda R Hemmelgarn
Background: Low 25-hydroxyvitamin D levels are a global health problem with northern countries such as Canada at particular risk. A number of sociodemographic factors have been reported to be associated with low vitamin D levels but prior studies have been limited by the ability of the researchers to gather this data directly from clinical trial participants. The purpose of this study was to use a novel methodology of inferring sociodemographic variables to evaluate the correlates of vitamin D levels in individuals dwelling in the City of Calgary, Alberta, Canada.
Methods: We utilized data on vitamin D test results from Calgary Laboratory Services between January 1 2010 and August 31 2011. In addition to vitamin D level, we recorded age, sex, and vitamin D testing month as individual-level variables. We inferred sociodemographic variables by associating results with census dissemination areas and using Census Canada data to determine immigration status, education, median household income and first nations status as clustered variables. Associations between vitamin D status and the individual- and dissemination area-specific variables were examined using the population-averaged regression model by a generalized estimating equations approach to account for the clustering in the data.
Results: 158,327 individuals were included. Age, sex, month of vitamin D testing (at an individual level), and education, immigrant status, first nations status and income (at an aggregate level) were all statistically significant predictors of vitamin D status.
Conclusions: Vitamin D status was associated with a number of sociodemographic variables.
Knowledge of these variables may improve targeted education and public health initiatives.
The more post-secondary education the more vitamin D
The more people born outside of Canada in the census track, the lower the vitamin D levels
Note: born outside of Canada = darker skin or concealing clothes
PDF is attached at the bottom of this page
See also Vitamin D Life
- Immigrants and refugees had lower vitamin D levels – Jan 2013
- Concealing Clothing in Canada: half the level of vitamin D in blood – May 2012
- Black Sudanese children 350X more likely to have rickets than other Australians – April 2012
- Low vitamin D associated with poor regions in the UK, median was 10 ng – Nov 2012
- Immigrant vitamin D deficiency in Europe – May 2011
- Overview Dark Skin and Vitamin D
- Low vitamin D 5 times more likely in poor and ethnic neighborhoods (than the best in Dublin) – Nov 2016