[Folic acid determination in the serum and erythrocytes by means of a competitive binding method with 125 iodine labeling]

Abstract

Folic acid concentration in serum and erythrocytes was measured by radio assay according to the principle of competitive binding to proteins with 125I as marker. The method yielded a linear regression with readily reproducible results. The mean value in controls was 7.05 -+/ 3.4 ng/ml in serum and 386.8 -+/ 215.1 ng/ml in erythrocytes. In chronic alcoholics the respective values were significantly lower: 4.79 -+/ 2.02 ng/ml for serum and 344.4 -+/ 198.9 ng/ml for erythrocytes. The clinical importance of folic acid estimations arises from the general frequency of folic aicd deficits. Latent folic acid deficiency is associated with lowered folic acid concentrations in serum and normal values in red cells. In manifest folic acid deficiency both concentrations are decreased.