Genetic polymorphisms of vitamin B12 and folate transporter proteins and depression in postpartum period: A case-control study

•First study to explore association of vitamin B12 and folate transporter protein polymorphisms (TCN-2 C776G and RFC-1 G80A) with depression in postpartum period.•No association was observed between TCN-2 C776G and RFC-1 G80A & postpartum.•TCN2 C776G CG genotype was associated with lower 5-methylTHF and SAM levels.•RFC-1 G80A GA genotype was associated with lower vitamin B12 levels.•Observations suggest the role of transporter genotype on vitamin B12 and folate homoeostasis.