Table 1

Folate intake (μg/day) assessed by the dietary records and food frequency questionnaire, and their correlation coefficients.

DR¹

FFQ²

Spearman correlation

Mean ± SD

Median

Range

Mean ± SD

Median

Range

% difference of mean

Crude

Energy-adjusted³

Deattenuated

Cohort I

Men (n = 102)

425 ± 103

427

210–735

473 ± 231

444

119–1807

11

0.49

0.40

0.57

Women (n = 113)

389 ± 106

380

153–667

476 ± 287

419

146–1978

22

0.29

0.35

0.47

Cohort II

Men (n = 174)

467 ± 156

443

197–1280

421 ± 190

370

85–1178

-10

0.33

0.50

0.63

Women (n = 176)

426 ± 112

417

198–980

454 ± 237

397

4–1498

7

0.42

0.48

0.63

¹ DR, dietary records

² FFQ, food frequency questionnaire.

³ Folate was adjusted for total energy intake using the residual method.

Ishihara et al. Nutrition Journal 2005 4:26   doi:10.1186/1475-2891-4-26