Hegsted M, Linkswiler H M
J Nutr. 1981 Feb;111(2):244-51. doi: 10.1093/jn/111.2.244.
The long-term effect of level of protein intake on calcium metabolism, renal function and renal acid excretion was determined during a 75-day metabolic study. Six women consumed a diet containing either 46 or 123 g protein for 60 days; they then consumed the alternate diet for 15 days. Calcium, phosphorus and magnesium intakes were maintained constant at 500, 900 and 350 mg, respectively, throughout the 75-day study. Urinary calcium was remarkably constant with time at both levels of protein intake but was approximately twice as high when the 123 g protein diet was consumed. Level of protein intake had no effect on calcium absorption; the increase in urinary calcium found when the high protein diet was given, therefore, caused a markedly negative calcium balance. Glomerular filtration rate (GFR) and renal acid excretion were higher and fractional renal tubular reabsorption of calcium was lower when the high protein diet was given. The hypercalciuria caused by the high protein intake was due primarily to the decrease in fractional tubular reabsorption of calcium and, to a lesser extent, to the increase in GFR. Neither GFR, fractional renal tubular reabsorption of calcium nor any of the components of renal acid excretion exhibited any tendency to change with time over the 60-day experimental period.
在一项为期75天的代谢研究中，确定了蛋白质摄入量对钙代谢、肾功能和肾酸排泄的长期影响。六名女性连续60天食用含46克或123克蛋白质的饮食；然后她们交替食用另一种饮食15天。在整个75天的研究中，钙、磷和镁的摄入量分别保持在500毫克、900毫克和350毫克不变。在两种蛋白质摄入水平下，尿钙随时间变化都非常稳定，但食用123克蛋白质饮食时，尿钙约为原来的两倍。蛋白质摄入量对钙吸收没有影响；因此，食用高蛋白饮食时尿钙增加导致明显的负钙平衡。食用高蛋白饮食时，肾小球滤过率（GFR）和肾酸排泄增加，肾小管对钙的重吸收分数降低。高蛋白摄入引起的高钙尿主要是由于肾小管对钙的重吸收分数降低，在较小程度上是由于GFR增加。在60天的实验期内，GFR、肾小管对钙的重吸收分数以及肾酸排泄的任何组成部分均未表现出随时间变化的趋势。
