Red blood cell uptake of supplemental folate in patients on anticonvulsant drug therapy.

Abstract

A group of epileptics (n = 18) and a control group (n = 10) of subjects aged 21-42 y were given 1-mg supplements of folate daily for 1 mo. Anticonvulsant therapy involved phenytoin alone or in combination with phenobarbital. Serum and red blood cell (RBC) folate levels were determined on days 1, 14, and 28. Mean serum and RBC folate levels were greater (p less than 0.05) for the control subjects compared with the epileptic subjects throughout the study. The percent increase in either serum or RBC folate was not different (p greater than 0.05) between the groups. The percent increase in serum folate when expressed as a percent of RBC folate was greater (p less than 0.05) for those epileptics who initially had deficient blood folate levels (serum folate less than 7 nmol/L; RBC folate less than 317 nmol/L) than those who did not. Deficient epileptics may have had an impaired RBC incorporation of circulating (serum) folate compared with nondeficient epileptics.