Purpose <p>A meta-analysis found significant inverse relationships between intake of vitamins B₁₂, B₆, and B₂ and depression only in women. The current prebirth cohort study investigated the associations between intake of folate and vitamins B₁₂, B₆, and B₂ during pregnancy and postpartum depressive symptoms.</p> Methods <p>Subjects were 1316 Japanese women. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. The Edinburgh Postnatal Depression Scale (EPDS) was completed between 3 and 4 months postpartum. Postpartum depressive symptoms were defined as EPDS score ≥ 9. Adjustment was made for age, gestation at baseline, region of residence, number of children at baseline, family structure, history of depression, family history of depression, employment, education, household income, body mass index, having smoked during pregnancy, vitamin B complex supplement use during pregnancy, cesarean section, baby’s sex, and baby’s birthweight.</p> Results <p>The prevalence of postpartum depressive symptoms was 8.2%. Compared with vitamin B₂ intake in the lowest quartile, intake in the third, but not second or fourth, quartile was independently associated with a reduced risk of postpartum depressive symptoms; the association was U-shaped, and the adjusted odds ratio for the third quartile was 0.53 (95% confidence interval: 0.28 − 0.97).</p> Conclusion <p>Intake of folate, vitamin B₁₂, and vitamin B₆ was not associated with postpartum depressive symptoms. Moderate vitamin B₂ consumption may be preventive against postpartum depressive symptoms.</p>