Abstract
The level of added inorganic sulfate required by adult rats fed semipurified diets was determined by measuring the percentage of a test dose of 1-14C-methionine expired as 14CO2 in a 3-hour period. 1-14C-Methionine was selected for determination of optimal dietary sulfate level after it was determined that three times more 14CO2 was expired from 1-14C-methionine in 3 hours than from U-14C-cysteine. Based on the assumption that as dietary sulfate spared methionine the 14CO2 expiration would decrease, the optimum level of dietary inorganic sulfate was found to be 0.02%.