What function do vitamin B12 and folic acid perform that is critical to hematopoiesis?: (A) Suppo porphyrin production, (B) Serve as cofactors for iron uptake, (C) Suppo terminal differentiation of erythroid and myeloid cells, (D) Suppo production of thymidine triphosphate
Answer is D. Cell proliferation requires DNA replication, which requires an adequate supply of thymidine triphosphate. Both vitamin B12 and folate are needed to make thymidine triphosphate.