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.
Wu
Hongyu
H
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon SK, Canada.
Gozdzik
Agnes
A
Barta
Jodi Lynn
JL
Wagner
Dennis
D
Cole
David E
DE
Vieth
Reinhold
R
Parra
Esteban J
EJ
Whiting
Susan J
SJ
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