Women who took folic acid (B-vitamin) supplements for more than six months while pregnant were less likely to have postpartum depression.   

In this study, doctors checked for postpartum depression in 1,592 women six to 12 weeks after giving birth. About half the women had taken a folic acid supplement during pregnancy.

Women who had taken folic acid for more than six months while pregnant were 24 percent less likely to develop postpartum depression compared to women who took folic acid for a shorter time or women who had not taken folic acid while pregnant.

Doctors also compared social, economic, family history, and individual health factors in the women and found that taking folic acid for more than six months while pregnant reduced postpartum depression regardless of any of these other factors.

Reference: Nutrients; 2017, Vol. 9, 1206.