A 3-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
Tj. Green et al., A 3-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, The Journal of nutrition, 128(10), 1998, pp. 1665-1671
The purpose of this study was to validate a food-frequency questionnai
re (FFQ) and a 3-d weighed food record (3d-WFR) by comparing nutrient
intakes estimated using these methods with serum folate, RBC folate an
d serum vitamin B-12 concentrations in 105 females aged 16-19 y. Durin
g an early morning clinic visit, subjects completed a self-administere
d, 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 intak
es from the FFQ (r = 0.48, P < 0.01) (P = 0.017). The correlations bet
ween 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. Vit
amin B-12 intakes showed only a modest association with serum vitamin
B-12 when supplement users were included in the analyses (FFQ, r = 0.2
5, P < 0.05; 3d-WFR, r = 0.32, P < 0.05). After excluding supplement u
sers 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 mu g) and vitamin B-12 (4.9
vs. 1.9 mu g) estimated from the FFQ were higher than those obtained f
rom the 3d-WFR. In sum, these data suggest that both the FFQ and 3d-WF
R are valid measures of assessing the folate intake of young women, an
d both appear to be useful in determining vitamin B-12 intake when sup
plemental users are included. The markedly different conclusions about
absolute folate and vitamin B-12 intakes obtained using these two die
tary methodologies should be taken into consideration when making reco
mmendations about optimal folate intakes in relation to disease preven
tion.