Folic acid status of patients with chronic renal failure maintained by dialysis.

Twenty-five uremic patients on chronic hemodialysis were followed over a period of 9 months with regard to hemoglobin, mean corpuscular volume and folate concentration in serum and erythrocytes. The daily dietary intake of folic acid was estimated at 80-90 microgram, and no folic acid supplements were given. None of the patients developed macrocytic anemia. At the end of the period all patients had a normal erythrocyte folate content. Serum folate was normal in 17 and below normal in 8 patients. These 8 patients were in a negative folate balance at the time of investigation. In 7 patients dialyzed with a RP VI dialyzer the maximum loss of folic acid was 75 microgram/dialysis, and in 6 patients on chronic intermittent peritoneal dialysis the maximum loss was 13 microgram/dialysis. Thus there is no need for oral folic acid supplementation in uremic patients on chronic dialysis provided that daily dietary intake of folic acid is adequate.