The prevalence and determinants of adequate vitamin D intake and supplementation among Canadian children

  • Author / Creator
    Munasinghe, Dona, LL.
  • Most Canadian children are not meeting the dietary recommendations for vitamin D and have not enough sun exposure to synthesize vitamin D in their skin. Vitamin D supplementation therefore seems a necessity. However, no study has examined whether vitamin D from diet and supplements combined is enough to meet the Canadian recommendations. Likewise, no earlier study examined factors associated with vitamin D intake from diet and supplements, which is important information for public health decision makers and public health interventions. Therefore, this study aimed to assess the adequacy of vitamin D intake through both diet and supplements (objective 1), the determinants of meeting dietary guidelines (objective 2), and to assess the prevalence (objective 3) and the determinants of the use of vitamin D supplements (objective 4) and multivitamins (objective 5) among children in the province of Alberta, Canada. In 2014, a representative sample of grade five students (10-11y) in Alberta (n=2,686) was surveyed. Data on dietary intake and the use of supplements were obtained using a modified Harvard Youth/Adolescent Food Frequency questionnaire. Parents were asked how much they cared about healthy foods and physical activity and if they encouraged their child to eat healthy foods and be physically active. The adequacy of vitamin D intake was estimated using the two cut-offs given for the DRIs, i.e. the Estimated Average Requirement (EAR) of 400 International Units (IU) and the Recommended Dietary Allowance (RDA) of 600 IU. Mixed effect multiple logistic regression analysis was employed to identify the key correlates of meeting the DRIs and supplement use. Forty five percent of students met the EAR and 22% met the RDA through both diet and supplements. When vitamin D intake from diet alone was considered, only 16% and 2% met the EAR and the RDA, respectively. Out of 29% of vitamin D supplement users, 12% used supplements on a daily basis. Although 54% used multivitamins, only 28% used them on a daily basis. Parental education, household income and physical activity were positively correlated with meeting the DRIs, and students attending metropolitan area schools were more likely to meet the EAR than students attending rural area schools. Students who resided in a metropolitan area, who were more physically active, or whose parents completed college were more likely to take vitamin D supplements, independent of student’s gender, household income, body weight status and dietary practices. Students were more likely to supplement with vitamin D if their parents cared about and encouraged eating healthy foods and also cared about physical activity. The prevalence of vitamin D supplement use was highest among those who had a high vitamin D diet and those with under/normal body weight status, although supplement use was not statistically associated with either dietary vitamin D intake or body weight status. Household income, parental education and physical activity were positively associated with multivitamin use and students of parents who personally cared about eating healthy foods were more likely to take multivitamins. Public health initiatives are needed to promote supplementation of vitamin D among Albertan children. Parental awareness on the importance of providing the correct dose of vitamin D supplements to meet dietary recommendations and, educating and encouraging parents about healthy lifestyles should be a part of such initiatives.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Specialization
    • Public Health (Epidemiology)
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Noreen Willows (Agric, Food & Nutritional Science)
    • Don Voaklander (School of Public Health)
    • Yan Yuan (School of Public Health)