in Folate Deficiency

The depressed serum B12 levels ac-companying folate deficiency gener-ally increase following folic acid ther-apy, and this phenomenon is cited as evidence that true B12 deficiency did not preexist in such instances. In this study, the metabolic significance of reduced serum B12 levels complicating folate deficiency was determined in bone marrow cultures by evaluation of abnormal incorporation of deoxyuri-dine into DNA-thymine, a defect char-acteristic of megaloblastic maturation due to folate or B12 deficiency. In in vitro marrow cultures of seven patient