Folate-dependent serine synthesis in lymphocytes from controls and patients with megaloblastic anaemia: the effect of therapy.

The utilization of [14C]formate for serine synthesis by lymphocytes was impaired in all the patients with pernicious anaemia and in 70% of other patients with megaloblastic anaemia. In pernicious anaemia this was corrected by vitamin B12 therapy in 48 h but not by folate therapy although patients given folate showed a satisfactory haematological response.