Stephensen C B, Alvarez J O, Kohatsu J, Hardmeier R, Kennedy J I, Gammon R B
Department of International Health, University of Alabama at Birmingham 35294.
Am J Clin Nutr. 1994 Sep;60(3):388-92. doi: 10.1093/ajcn/60.3.388.
Episodes of acute infection are thought to deplete body stores of vitamin A. The mechanism by which this might occur is not known, but increased metabolic requirements are presumed to play a role. We have found, however, that significant amounts of retinol and retinol-binding protein (RBP) were excreted in the urine during serious infections, whereas only trace amounts were found in the urine of healthy control subjects. The geometric mean excretion rate in 29 subjects with pneumonia and sepsis was 0.78 mumol retinol/d. Subjects with fever (temperature > or = 38.3 degrees C) excreted significantly more retinol (geometric mean = 1.67 mumol/d) than did those without fever (0.18 mumol/d; t = 3.53, P < 0.0015). Aminoglycoside administration 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 mumol retinol/d, equivalent to 50% of the US recommended dietary allowance. These data show that vitamin A requirements are substantially increased during serious infections because of excretion of retinol in the urine, and suggest that these losses are due to pathologic changes associated with the febrile response.
急性感染发作被认为会耗尽体内的维生素A储备。其发生机制尚不清楚，但推测增加的代谢需求起了作用。然而，我们发现，在严重感染期间，大量的视黄醇和视黄醇结合蛋白（RBP）从尿液中排出，而在健康对照者的尿液中仅发现微量。29名患有肺炎和败血症的受试者的几何平均排泄率为0.78 μmol视黄醇/天。发热（体温≥38.3℃）的受试者排出的视黄醇明显多于未发热的受试者（几何平均值分别为1.67 μmol/天和0.18 μmol/天；t = 3.53，P < 0.0015）。使用氨基糖苷类药物和低肾小球滤过率（< 35 mL/分钟）也与较高的尿视黄醇排泄率相关。34%的患者视黄醇排泄量> 1.75 μmol/天，相当于美国推荐膳食摄入量的50%。这些数据表明，在严重感染期间，由于视黄醇从尿液中排出，维生素A的需求量大幅增加，并且表明这些损失是由于与发热反应相关的病理变化所致。
