Validation of a short food frequency questionnaire for assessment of dietary calcium intake in women.
OBJECTIVE
To assess the ability of a short food frequency questionnaire to measure dietary calcium intake in women.


METHODS
Estimates of calcium intake from the food frequency questionnaire were compared with those from seven-day estimated records in 58 Caucasian women aged 25-49 years in Dunedin, New Zealand.


METHODS
Subjects were recruited through poster and newspaper advertising around the central business district of Dunedin, New Zealand. Of 69 subjects initially recruited, nine failed to complete diet records and two were excluded on the basis that their diet record was unlikely to represent habitual intake.


RESULTS
Mean dietary calcium intakes were 808.1mg/day from the estimated record and 776.9mg/day from the questionnaire. The mean difference in intake by the two methods (31.1mg, SD = 234.0, 95% CI = -30.4-92.7, p = 0.3) did not differ significantly from zero. The questionnaire classified women consuming less than 800mg calcium per day with 78% specificity. 81% of subjects when classified by the records fell into the same or adjacent quartiles when classified by the questionnaire. Only two subjects were grossly misclassified.


CONCLUSIONS
The short food frequency questionnaire could be used to assess mean dietary calcium intake in young to middle aged women. The specificity of the questionnaire is high in identifying women who consume < 800mg calcium/day, therefore it could be used to target interventions for those with intakes below this level.
Wilson
P
P
Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
Horwath
C
C
D000328:Adult; D015992:Body Mass Index; D002136:Calcium, Dietary / Q000008:administration & dosage*; D015930:Diet Records; D005260:Female; D006801:Humans; D008875:Middle Aged; D009520:New Zealand; D015596:Nutrition Assessment; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D016387:Women's Health
D002136:Calcium, Dietary