Validity and reproducibility of folate and vitamin B12 intakes estimated from a self-administered diet history questionnaire in Japanese pregnant women

Table 5 Mean daily intakes and Intraclass Correlation Coefficients between intakes estimated from the two-time DHQ (n = 58)

	1st DHQ	2nd DHQ		1st DHQ + 2nd DHQ Intraclass Correlation Coefficient
	Mean ± SD	Mean ± SD	p ¹
Energy [kcal/day]	1727 ± 407	1771 ± 399	0.523	0.599
Folate [μg/day]²	292 ± 120	279 ± 112	0.257	0.725
Vitamin B₁₂ [μg/day]²	5.37 ± 2.79	5.91 ± 2.95	0.052	0.512

DHQ: self-administered diet history questionnaire
¹The paired t-test
²The analyses were performed after log-transformation of the variables to achieve normal distribution

ISSN: 1475-2891