title: A food frequency questionnaire for the assessment of calcium, vitamin D and vitamin K: a pilot validation study.
abstract: The study objective was to validate a food frequency questionnaire (FFQ) to assess calcium, vitamin D and vitamin K intakes in overweight and obese postmenopausal community-dwelling women. The FFQ was validated against intakes derived from a 5-day diet record (5DDR) that also included assessment of supplement intake. Strong correlations between methods were observed for all nutrients (r = 0.63, 0.89, 0.54 for calcium, vitamin D and vitamin K, respectively) and cross-classification analyses demonstrated no major misclassification of participants into intake quartiles. Bland-Altman analysis showed that the FFQ overestimated intakes for calcium, by 576 mg/day (95% CI, -668 to 1,821 mg/day), for vitamin D by 75 IU/day (95% CI, -359 to 510 IU/day), and for vitamin K by 167 mcg/day (95% CI, -233 to 568 mcg/day). This pilot study showed promising validation evidence for the use of this FFQ, which focuses on calcium, vitamin D and vitamin K intakes in postmenopausal women, as a screening tool in clinical and research settings.
authors.affiliation: McMaster University, W. Hamilton ON L8N 3Z5, Canada. pritcjm@mcmaster.ca
authors.forename: Janet M
authors.initials: JM
authors.lastname: Pritchard
authors.forename: Tinasha
authors.initials: T
authors.lastname: Seechurn
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Atkinson
mesh_terms: D000368:Aged; D002136:Calcium, Dietary / Q000008:administration & dosage*; D004034:Diet Surveys / Q000592:standards*; D005260:Female; D006801:Humans; D015596:Nutrition Assessment; D009765:Obesity; D050177:Overweight; D010865:Pilot Projects; D017698:Postmenopause; D011795:Surveys and Questionnaires / Q000592:standards*; D014807:Vitamin D / Q000008:administration & dosage*; D014812:Vitamin K / Q000008:administration & dosage*
chemical_list: D002136:Calcium, Dietary; D014812:Vitamin K; D014807:Vitamin D