Endocrine Abstracts

Introduction and aims: Adequate dietary calcium (Ca) intake is important for maintenance of bone health. In a clinical setting we employ a simple Food Frequency Questionnaire (FFQ) for rapid assessment of dietary Ca intake. In this study we have validated our FFQ using a 3-day food diary (3FD) in children presenting to our metabolic bone and endocrine clinics.

Methods: Dietary Ca intake values estimated using the FFQ were compared to those estimated by the 3FD in the same children. Daily dietary Ca intake values from 3FDs were calculated using the Microdiet Software (Downlee Systems Ltd, UK).

Results: FFQ data was obtained from 74 children out of which 32 children (age 1–17 years) completed a 3FD. Mean daily Ca intakes (±S.D.) were 875±580 and 878±329 mg, estimated by FFQ and 3FD respectively. There was a significant positive correlation between dietary Ca estimated by 3FD and FFQ (r=0.69; P<0.01). The degree of agreement between the two methods was assessed using a Bland–Altman plot. The majority of data points fell within ±1.96S.D. of the mean, indicating a good level of agreement between the two methods. The FFQ had a specificity of 93% in identifying children who consumed inadequate amount of dietary Ca based on UK’s Reference Nutrient Intake (RNI) for their respective age group. The FFQ had a sensitivity of 78% in identifying children whose dietary Ca intake exceeded RNI.

Conclusions: Results of this study suggest that our FFQ is useful for rapid assessment of children’s daily dietary Ca intake.