Table 2

Mean intakes estimated from a self-administered diet-history questionnaire and mean serum concentrations

All participants (n = 167)

S Hospital

(n = 76)

T Hospital

(n = 91)

Mean ± SD

Mean ± SD

Mean ± SD

p¹

Intakes

Energy [kcal/day]

1823 ± 373

1832 ± 377

1815 ± 372

0.770

Folate [μg/day]²

261 ± 107

215 ± 76

299 ± 114

< 0.001

[μg/1,000 kcal]²

142 ± 48

117 ± 30

164 ± 50

< 0.001

Vitamin B₁₂ [μg/day]²

5.74 ± 3.10

5.66 ± 3.54

5.80 ± 2.70

0.328

[μg/1,000 kcal]²

3.10 ± 1.35

3.01 ± 1.49

3.17 ± 1.22

0.200

Serum concentrations

Folate [ng/ml]²

6.57 ± 2.80

5.25 ± 2.52

7.67 ± 2.55

< 0.001

Vitamin B₁₂ [pg/ml]²

268 ± 99

199 ± 69

325 ± 83

< 0.001

¹Student's t-test

²The analyses were conducted after log-transformation of the variables

Shiraishi et al. Nutrition Journal 2012 11:15   doi:10.1186/1475-2891-11-15