title: Decreased serum B 12  levels with oral contraceptive use.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D003276:Contraceptives, Oral / Q000009:adverse effects* / Q000494:pharmacology; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D005865:Gestational Age; D006400:Hematocrit; D006801:Humans; D011247:Pregnancy; D011485:Protein Binding / Q000187:drug effects; D012546:Schilling Test; D013997:Time Factors; D014805:Vitamin B 12 / Q000097:blood* / Q000378:metabolism; D014806:Vitamin B 12 Deficiency / Q000139:chemically induced
chemical_list: D003276:Contraceptives, Oral; D005492:Folic Acid; D014805:Vitamin B 12