Kumar R, Wiesner R, Scott M, Go V L
Am J Physiol. 1982 Nov;243(5):E370-4. doi: 10.1152/ajpendo.1982.243.5.E370.
We determined the metabolic clearance and production rates of 24,25-dihydroxyvitamin D3 in four normal healthy adults. We also examined the excretion of radioactivity in stool, urine, and bile after the intravenous administration of 24,25-[3H]dihydroxyvitamin D3 to human subjects. 24,25-Dihydroxyvitamin D3 is rapidly cleared from the plasma with a half-life of approximately 390 +/- 25 min (mean +/- SE). The metabolic clearance rate of 24,25-dihydroxyvitamin D3 was 9.2 +/- 1.5 liters/day with a production rate of 26.4 +/- 7.2 micrograms/day (mean +/- SE). Within 1 day 13.0 +/- 4.2% (mean +/- SE) of the administered dose had appeared in the stool; by day 7, 48.8 +/- 2.7% of the dose had appeared in the feces. Within 24 hr, 6.4 +/- 0.8% of the administered dose appeared in the urine; 7.4 +/- 1.8% of the dose had appeared in the urine within 2 days. The biliary excretion of 24,25-dihydroxyvitamin D3 was studied in two subjects. By 8 h, 15.3 +/- 1.3% of the administered dose had appeared in the bile. The metabolites present in bile, feces, and urine were much more polar than 24,25-dihydroxyvitamin D3. These results demonstrate that 24,25-dihydroxyvitamin D3 is rapidly cleared from plasma and is excreted in the feces (probably via the bile) and urine of normal human subjects.
我们测定了四名正常健康成年人中24,25-二羟基维生素D3的代谢清除率和生成率。我们还研究了在向人体受试者静脉注射24,25-[3H]二羟基维生素D3后，粪便、尿液和胆汁中的放射性排泄情况。24,25-二羟基维生素D3从血浆中迅速清除，半衰期约为390±25分钟（平均值±标准误）。24,25-二羟基维生素D3的代谢清除率为9.2±1.5升/天，生成率为26.4±7.2微克/天（平均值±标准误）。给药剂量的13.0±4.2%（平均值±标准误）在1天内出现在粪便中；到第7天，48.8±2.7%的剂量出现在粪便中。给药剂量的6.4±0.8%在24小时内出现在尿液中；2天内7.4±1.8%的剂量出现在尿液中。在两名受试者中研究了24,25-二羟基维生素D3的胆汁排泄情况。到8小时时，给药剂量的15.3±1.3%出现在胆汁中。胆汁、粪便和尿液中存在的代谢产物比24,25-二羟基维生素D3极性大得多。这些结果表明，24,25-二羟基维生素D3从血浆中迅速清除，并在正常人体受试者的粪便（可能通过胆汁）和尿液中排泄。
