FOLIC-ACID ABSORPTION IN WOMEN WITH A HISTORY OF PREGNANCY WITH NEURAL-TUBE DEFECT

Folic acid absorption was compared in nonpregnant women with a history of pregnancy with a neural tube defect (cases) (n = 10) with that of control women (n = 10) with a normal pregnancy history. [H-2(4)]folic acid was administered in an oral dose (400 mu g) to fasting case and control subjects after a 30-d saturation protocol involving daily ingestion of two 1-mg folic acid supplements. Serum and red blood cell folate concentrations were not different for case and control subjects before or during the saturation protocol (P > 0.05). The percentage ((x) over bar +/- SD) of the oral dose of [H-2(4)]folic acid excreted in 24-h urine collections postdose was not different (P > 0.05) for case compared with control subjects (9.05 +/- 2.25% and 11.10 +/- 3.41%, respectively). These data suggest that the absorption of folic acid routinely consumed in supplements and fortified food products is not impaired in women with a history of a pregnancy with a neural tube defect. Further case-controlled studies are needed to compare the absorption of the predominant dietary form of the vitamin.