Keltz F R, Kies C, Fox H M
Am J Clin Nutr. 1978 Jul;31(7):1167-71. doi: 10.1093/ajcn/31.7.1167.
The objective of the project was to study the effect of dietary pectin, cellulose, hemicellulose, and zinc on human urinary excretion of ascorbic acid. The project consisted of two 33-day controlled feeding studies involving a total of 19 adult men and women normal health. Within each study all subjects received all experimental treatments. In study A during the four 7-day experimental periods the ground peanut based diets were varied as follows: no supplement, 14.2 g of hemicellulose supplement, 14.2 g of cellulose supplement, or 14.2 g of pectin supplement per subject per day. Mean urinary excretion of ascorbic acid by subjects while receiving these supplements were 26.10, 32.27, 26.27, or 20.60 mg/day, respectively. In study B during the four 7-day randomly arranged experimental periods, the following alterations were made to the basal diet: supplement of 14.2 g of pectin plus 1.3 g of zinc, 14.2 g of pectin plus 9.3 g of zinc, 4.2 g pectin plus 1.3 g of zinc, and 4.2 g of pectin plus 9.3 g of zinc. Mean urinary ascorbic acid excretion of subjects while receiving these diets were as follows: 20.61, 23.18, 28.07, 18.99. Hemicellulose supplement enhanced urinary excretion of ascorbic acid while pectin and zinc resulted in decreased urinary excretion of this vitamin. Increased urinary excretion of ascorbic acid at constant intake levels is thought usually to be indicative of enhanced absorption or of decreased need.
该项目的目的是研究膳食中的果胶、纤维素、半纤维素和锌对人体抗坏血酸尿排泄的影响。该项目包括两项为期33天的对照喂养研究，共有19名健康的成年男性和女性参与。在每项研究中，所有受试者都接受了所有的实验处理。在研究A中，在四个为期7天的实验期内，以花生为基础的饮食按以下方式变化：不添加补充剂、每人每天添加14.2克半纤维素补充剂、14.2克纤维素补充剂或14.2克果胶补充剂。受试者在接受这些补充剂时抗坏血酸的平均尿排泄量分别为26.10、32.27、26.27或20.60毫克/天。在研究B中，在四个随机安排的为期7天的实验期内，对基础饮食进行了以下改变：添加14.2克果胶加1.3克锌、14.2克果胶加9.3克锌、4.2克果胶加1.3克锌以及4.2克果胶加9.3克锌。受试者在接受这些饮食时抗坏血酸的平均尿排泄量如下：20.61、23.18、28.07、18.99。半纤维素补充剂可提高抗坏血酸的尿排泄量，而果胶和锌则导致这种维生素的尿排泄量减少。在摄入量恒定的情况下，抗坏血酸尿排泄量增加通常被认为表明吸收增强或需求减少。
