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

Table 3 Correlation coefficients between intakes and serum concentrations of folate and vitamin B₁₂

	Corresponding serum concentrations
	All participants (n = 167)		Participants without nausea (n = 121)²
	r	p ¹	r	p ¹
Intakes ³
Folate [μg/day]	0.251	0.001	0.245	0.007
[μg/1,000 kcal]	0.286	< 0.001	0.280	0.002
Vitamin B₁₂ [μg/day]	0.174	0.025	0.249	0.006
[μg/1,000 kcal]	0.222	0.004	0.313	0.001

¹Partial correlation analysis. Adjusted for research settings
All variables were log-transformed before analyses
²The participants with nausea were excluded from the analyses
³Folate and vitamin B₁₂ intakes were assessed by a self-administered diet history questionnaire (DHQ)

ISSN: 1475-2891