Michelle Science1,2, Jonathon L Maguire3,4,5,6, Margaret L Russell7, Marek Smieja2,8, Stephen D Walter2, Mark Loeb2,8,9. 1. Division of Infectious Diseases, The Hospital for Sick Children, Toronto, Ontario. 2. Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton Health Sciences, Hamilton, Ontario. 3. Applied Health Research Centre, Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Ontario. 4. Department of Paediatrics, St Michael's Hospital, Toronto, Ontario. 5. Institute for Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario. 6. Department of Pediatrics, University of Toronto, Toronto, Ontario. 7. Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta. 8. Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario. 9. Michael G DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario.
Abstract
OBJECTIVES: Studies in Canada have reported varying prevalences of low serum 25-hydroxyvitamin D (25(OH)D) levels, but none have been conducted in rural paediatric populations. The purpose of this study was to determine the prevalence and predictors of low vitamin D levels in rural communities. METHODS: We conducted a cross-sectional study of children aged 3 to 15 living in Canadian Hutterite communities. Serum 25(OH)D levels were measured between October 2008 and April 2009 using a chemiluminescence assay. Predictors of vitamin D levels were evaluated using multivariable linear regression. A multilevel model was used to evaluate the impact of individual, household and colony factors on the variation in vitamin D levels. RESULTS: Serum 25(OH)D levels were available on 743 children/adolescents. The median was 62.0 nmol/L (interquartile range 51.0, 74.0). Levels lower than 50 nmol/L and 75 nmol/L were found in 152 (20.5%) and 565 (76%) children, respectively. Adolescents were at highest risk for levels <75 nmol/L (odds ratio 3.38, 95% confidence interval 2.00, 5.80). Age and latitude were negatively correlated with serum 25(OH)D level. In the multilevel model, most of the variation in levels was associated with individual children. CONCLUSION: Low vitamin D levels are a significant problem in rural Hutterite communities in Canada. Adolescents were at greatest risk for low levels and represent an important target group for supplementation. Variation in serum 25(OH)D levels was explained mostly at the individual level. Additional studies are needed to explore factors associated with individuals (e.g., genetics) leading to lower 25(OH)D levels.
OBJECTIVES: Studies in Canada have reported varying prevalences of low serum 25-hydroxyvitamin D (25(OH)D) levels, but none have been conducted in rural paediatric populations. The purpose of this study was to determine the prevalence and predictors of low vitamin D levels in rural communities. METHODS: We conducted a cross-sectional study of children aged 3 to 15 living in Canadian Hutterite communities. Serum 25(OH)D levels were measured between October 2008 and April 2009 using a chemiluminescence assay. Predictors of vitamin D levels were evaluated using multivariable linear regression. A multilevel model was used to evaluate the impact of individual, household and colony factors on the variation in vitamin D levels. RESULTS: Serum 25(OH)D levels were available on 743 children/adolescents. The median was 62.0 nmol/L (interquartile range 51.0, 74.0). Levels lower than 50 nmol/L and 75 nmol/L were found in 152 (20.5%) and 565 (76%) children, respectively. Adolescents were at highest risk for levels <75 nmol/L (odds ratio 3.38, 95% confidence interval 2.00, 5.80). Age and latitude were negatively correlated with serum 25(OH)D level. In the multilevel model, most of the variation in levels was associated with individual children. CONCLUSION: Low vitamin D levels are a significant problem in rural Hutterite communities in Canada. Adolescents were at greatest risk for low levels and represent an important target group for supplementation. Variation in serum 25(OH)D levels was explained mostly at the individual level. Additional studies are needed to explore factors associated with individuals (e.g., genetics) leading to lower 25(OH)D levels.
Authors: Jonathon L Maguire; Catherine S Birken; Deborah L O'Connor; Colin Macarthur; Kevin E Thorpe; Muhammad Mamdani; Patricia C Parkin Journal: Paediatr Child Health Date: 2011-02 Impact factor: 2.253
Authors: Anne C Looker; Christine M Pfeiffer; David A Lacher; Rosemary L Schleicher; Mary Frances Picciano; Elizabeth A Yetley Journal: Am J Clin Nutr Date: 2008-12 Impact factor: 7.045