Increased urinary excretion and prolonged turnover time of folic acid during ethanol ingestion.

The effect of ethanol on the kinetics of folic acid urinary excretion was studied in five chronic alcoholic patients who were maintained in a folate replete state. For 17 days, 95% ethanol was administered orally at 2-h intervals (X9). The folate pool(s) were labeled with the tritium labeled pteroyl glutamic acid at the start of the period of ethanol ingestion and at the start of a control abstinent period. The 24-h urine volume did not change with consumption of ethanol. Total urinary folate excretion was significantly greater by 20 to 40% in four of five patients during the ethanol administration period (p less than 0.05). The fall-off in urinary radioactivity corrected for total folate excretion (dpm/microgram Lactobacillus casei folate) was resolved into a biexponential decay with two distinct slopes. Ethanol caused the slope of the second component to flatten significantly with mean t1/2 of 63.7 days on ethanol versus 9.6 days off (p less than 0.05). These kinetic results are consistent with the known interference by ethanol of folate utilization in a functional tissue pool.