A Three-Day Weighed Food Record and a Semiquantitative Food-Frequency Questionnaire Are Valid Measures for Assessing the Folate and Vitamin B-12 Intakes of Women Aged 16 to 19 Years

Abstract

The purpose of this study was to validate a food-frequency questionnaire (FFQ) and a 3-d weighed food record (3d-WFR) by comparing nutrient intakes estimated using these methods with serum folate, RBC folate and serum vitamin B-12 concentrations in 105 females aged 16-19 y. During an early morning clinic visit, subjects completed a self-administered, 116-item FFQ, blood was collected and they were trained to complete a 3d-WFR. Folate intakes as determined by the 3d-WFR (r = 0.65, P < 0.01) exhibited a stronger association with serum folate than did intakes from the FFQ (r = 0.48, P < 0.01) (P = 0.017). The correlations between folate intakes and RBC folate as determined by the FFQ (r = 0.42, P < 0.01) and 3d-WFR (r = 0.50, P < 0.01) methods did not differ. Vitamin B-12 intakes showed only a modest association with serum vitamin B-12 when supplement users were included in the analyses (FFQ, r = 0.25, P < 0.05; 3d-WFR, r = 0.32, P < 0.05). After excluding supplement users from the analyses, the relationship between vitamin B-12 intakes as determined by FFQ and serum vitamin B-12 was no longer significant. Median daily folate intakes (346 vs. 212 microgram) and vitamin B-12 (4.9 vs. 1.9 microgram) estimated from the FFQ were higher than those obtained from the 3d-WFR. In sum, these data suggest that both the FFQ and 3d-WFR are valid measures of assessing the folate intake of young women, and both appear to be useful in determining vitamin B-12 intake when supplemental users are included. The markedly different conclusions about absolute folate and vitamin B-12 intakes obtained using these two dietary methodologies should be taken into consideration when making recommendations about optimal folate intakes in relation to disease prevention.

Validation of the assessment of folate and vitamin B12 intake in women of reproductive age: the method of triads

“…Our FFQ covers the intake of a reasonably long period of 4 weeks and may, therefore, demonstrate a higher correlation with RBC folate than with serum folate. For vitamin B 12 , the correlation was comparable with the report (0.19) of Green et al (1998).…”

“…Moreover, these B-vitamin intakes were similar to the Dutch dietary reference intakes with the exception of folate (Health Council of the Netherlands, 2001Netherlands, , 2003, which is known to be low in the Dutch diet (Konings et al, 2001;Groenen et al, 2004;van Rooij et al, 2004). The correlation between the FFQ and the biomarkers is slightly higher for RBC folate than reported by others (0.28 versus 0.08 and 0.25, respectively) (Green et al, 1998;Pufulete et al, 2002). Higher correlation coefficients of 0.38 and 0.39 were reported for serum folate (Green et al, 1998;Pufulete et al, 2002).…”

“…The correlation between the FFQ and the biomarkers is slightly higher for RBC folate than reported by others (0.28 versus 0.08 and 0.25, respectively) (Green et al, 1998;Pufulete et al, 2002). Higher correlation coefficients of 0.38 and 0.39 were reported for serum folate (Green et al, 1998;Pufulete et al, 2002). These differences can be explained by the better reflection of the recent dietary intake by serum folate, whereas the RBC folate concentration is a measure of the long-term folate status in particular (Bailey, 1990;Bates and Thurnham, 1995;Willett, 1998).…”

Validation of a food frequency questionnaire to assess folate intake of Dutch elderly people

“…Previous studies that determined correlations between erythrocyte concentrations and folate intake found correlations coefficients of 0·25 28 , 0·08 30 and 0·20 31 . Thus compared to other studies our correlations were moderate/low, but still significantly positive for serum folate.…”

“…that determined correlations between serum folate concentrations and folate intake estimated by a FFQ found correlation coefficients of 0·38 28 , 0·34 (crude) and 0·61 (adjusted) 29 , 0·06 30 , 0·42 31 and 0·13 32 . Previous studies that determined correlations between erythrocyte concentrations and folate intake found correlations coefficients of 0·25 28 , 0·08 30 and 0·20 31 .…”