VITAMIN-A IS EXCRETED IN THE URINE DURING ACUTE INFECTION

Episodes of acute infection are thought to deplete body stores of vita min A. The mechanism by which this might occur is not known, but incre ased metabolic requirements are presumed to play a role. We have found , however, that significant amounts of retinol and retinol-binding pro tein (RBP) were excreted in the urine during serious infections, where as only trace amounts were found in the urine of healthy control subje cts. The geometric mean excretion rate in 29 subjects with pneumonia a nd sepsis was 0.78 mu mol retinol/d. Subjects with fever (temperature greater than or equal to 38.3 degrees C) excreted significantly more r etinol (geometric ($) over bar chi = 1.67 mu mol/d) than did those wit hout fever (0.18 mu mol/d; t = 3.53, P < 0.0015). Aminoglycoside admin istration and low glomerular filtration rates (< 35 mL/min) were also associated with higher rates of urinary retinol excretion. Thirty-four percent of patients excreted > 1.75 mu mol retinol/d, equivalent to 5 0% of the US recommended dietary allowance. These data show that vitam in A requirements are substantially increased during serious infection s because of excretion of retinol in the urine, and suggest that these losses are due to pathologic changes associated with the febrile resp onse.