Sutton J L, Basu T K, Dickerson J W
Hum Nutr Appl Nutr. 1983 Apr;37(2):136-40.
Base-line values for the excretion of urea N, amine N, creatinine, uric acid and cysteine were measured in three consecutive 24-h urine collections from 16 healthy volunteers. The subjects then took 1 g ascorbic acid three times a day after meals for 7 days. Twenty-four hour urine samples were collected on the 1st, 3rd, 5th and 7th days of the study. Where possible, a further 24-h sample was collected a minimum of 10 d after the end of the study. Administration of 3 g/d of ascorbic acid had no effect on urine volume, pH or the excretion of urea, amino N or creatinine. It caused a transient increase in uric acid excretion but an immediate and sustained increase in the excretion of cysteine. This study provides no evidence for an effect of high doses of ascorbic acid on urinary stone formation but does suggest competition for important co-factors in the metabolism of drugs.
在连续三天收集16名健康志愿者的24小时尿液样本后，测量了尿素氮、胺氮、肌酐、尿酸和半胱氨酸的排泄基线值。之后，受试者在饭后每天三次服用1克抗坏血酸，持续7天。在研究的第1天、第3天、第5天和第7天收集24小时尿液样本。在可能的情况下，在研究结束后至少10天再收集一次24小时样本。每天服用3克抗坏血酸对尿量、pH值或尿素、氨基氮或肌酐的排泄没有影响。它导致尿酸排泄短暂增加，但半胱氨酸排泄立即且持续增加。这项研究没有提供高剂量抗坏血酸对尿路结石形成有影响的证据，但确实表明在药物代谢中存在对重要辅助因子的竞争。
