The development and evaluation of a food frequency questionnaire used in assessing vitamin D intake in a sample of healthy young Canadian adults of diverse ancestry.
Little data exist on vitamin D deficiency related with intake, especially for the Canadian population. The purpose of this study was to develop and evaluate a food frequency questionnaire (FFQ) with 37 items for rapid assessment of vitamin D intake in healthy young adults of diverse ancestry. We recruited 107 subjects in Southern Ontario during the late winter of 2007 who completed an FFQ twice (FFQ-1 and FFQ-2, repeated for reproducibility assessment) and a 7-day food diary (for validation). Serum 25-hydroxyvitamin D (25(OH)D), the major biomarker of vitamin D nutritional status, and skin melanin were determined. The FFQ results were highly correlated with 7-day diary results and with serum 25(OH)D concentrations (r = 0.529, P < .001; r = 0.481, P < .001, respectively). Modifications to the FFQ, by redefining the large serving size and excluding the fortified orange juice category, improved the validity of the FFQ (r = 0.602, P < .001; r = 0.520, P < .001, respectively). The FFQ results were highly correlated (r = 0.663, P < .001), but the mean intakes were different (P < .05). Using results from a modified version of FFQ-1, we examined dietary intakes in 3 predominant groups: East Asian (n = 27), European (n = 31), and South Asian (n = 32). The European group had higher total vitamin D intake (P < .05) and the highest serum 25(OH)D concentrations (P < .05), with a trend for dairy products being responsible for this (P < .10). Because Canadians are reliant on dietary intakes of vitamin D in the wintertime, especially those with higher skin melanin, our FFQ can monitor and provide information on intake and food group consumption.
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon SK, Canada.
Hongyu
H
Wu
Agnes
A
Gozdzik
Jodi Lynn
JL
Barta
Dennis
D
Wagner
David E
DE
Cole
Reinhold
R
Vieth
Esteban J
EJ
Parra
Susan J
SJ
Whiting
D000328:Adult; D044466:Asian People; D004032:Diet; D006801:Humans; D008543:Melanins / Q000032:analysis; D009864:Ontario; D015203:Reproducibility of Results; D012867:Skin / Q000737:chemistry; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000208:ethnology / Q000378:metabolism*; D044465:White People; D055815:Young Adult
D008543:Melanins; D014807:Vitamin D; C104450:25-hydroxyvitamin D