Previous reports have suggested deleterious effects on folate balance in users of contraceptives. A study of folate in 526 women attending a family-planning clinic demonstrated, both with the Lactobacillus casei assay and with a new radioassay, that the mean serum folate level for women taking oral contraceptives was not significantly lower than that for women in a control group. There was no correlation between serum folate level and length of time oral contraceptives were taken. Also, there was no macrocytosis or hypersegmentation of polymorphonuclear leukocytes and no case of macrocytic anemia in the 280 users of oral contraceptive agents. Probably, oral contraceptive agents do not cause folate deficiency anemia in otherwise normal subjects.
(JAMA 231:731-733, 1975)
Paine CJ, Grafton WD, Dickson VL, Eichner ER. Oral Contraceptives, Serum Folate, and Hematologic Status. JAMA. 1975;231(7):731-733. doi:10.1001/jama.1975.03240190035013