A food frequency questionnaire for estimation of vitamin D intake in adults

Validation of a food frequency questionnaire to determine vitamin D intakes using the method of triads

Weir et al., JHND Early View


Dietary sources of vitamin D (both natural and fortified) are increasingly contributing to consumers’ vitamin D intake and status. Therefore, the present study aimed to validate a vitamin D food frequency questionnaire (FFQ) for the assessment of habitual vitamin D intake.


A total of 49 apparently healthy consenting adults (aged 18–64 years) from the local community were sampled at the end of winter. Dietary intakes were recorded using a 4-day weighed food record (4d-WFR) and a 17-item FFQ based on foods known to contribute to dietary vitamin D intake. Fasting vitamin D status was quantified by serum 25-hydroxyvitamin D [25(OH)D] using liquid chromatography tandem mass spectrometry. The method of triads was applied using these three measurements to determine the overall validity of the FFQ.


Vitamin D intakes from 4d-WFR ranged between 0.42 and 31.65 μg day−1, whereas intakes determined from the FFQ ranged from 1.03 to 36.08 μg day−1. Serum 25(OH)D concentrations ranged between 12.89 and 279.00 nmol L−1. The mean (SD) difference between the FFQ and 4d-WFR was +1.62 ( 3.86). There were strong correlations between the vitamin D intake estimated by the FFQ and that from the 4d-WFR (= 0.562) and also with serum 25(OH)D concentrations (= 0.567). Vitamin D intake estimated from the 4d-WFR was also strongly correlated with serum 25(OH)D concentrations (= 0.411). The overall validity coefficient calculated using the method of triads was high (0.881).


The vitamin D FFQ has been validated for use in future studies aiming to assess habitual vitamin D intake.


Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s