目的：解决现行碳酸钙D₃制剂国家药品标准中维生素D₃的两份含量测定样品结果不平行的问题，建立准确、可靠的维生素D₃测定方法，为碳酸钙D₃制剂的质量控制提供技术支撑。方法：取制剂细粉，加入75%二甲基亚砜水溶液20 mL 45 ℃振摇提取15 min，放冷，精密加入稀释溶剂15 mL，密塞，振摇萃取90 min，3000 r·min^-1离心10 min，取上清液。结果：维生素D₃平均回收率（n=9）为99.18%，RSD（n=9）为1.01%，共测定11批碳酸钙D₃制剂，平行两份样品标准偏差均小于1.1%。结论：采用现行方法，维生素D₃在75%二甲基亚砜水溶中超声降解，导致样品测定结果偏差大，采用振摇提取的方式制备碳酸钙D₃制剂样品，方法准确可靠。建议将现行标准方法修改为“加入75%二甲基亚砜水溶液约20 mL，摇匀，45 ℃振摇提取15 min，放冷”。

Objective： To solve the problem that determination results of two vitamin D₃ assay samples are unparallel by current national drug standards for calcium carbonate and vitamin D₃ preparations. To establish the accurate and reliable assay method about vitamin D₃. To support the quality control of calcium carbonate and vitamin D₃ preparations.Methods： Add 20 mL of 75% dimethyl sulfoxide to the powder of the preparation， and shake at 45 ℃ for 15 min， then take it cool. Add 15 mL of diluted solvent to 75% dimethyl sulfoxide layer， and stopper it， then shake it for 90 min. Centrifuge it at 3 000 r·min^-1 for 10 min， and withdraw the diluted solvent layer.Results： The average recovery of vitamin D₃ （n=9） was 99.12%， RSD （n=9） was 1.03%. 11 batches of calcium carbonate and vitamin D₃ preparations were determined. The standard deviation of the two parallel samples was less than1.1%.Conclusion： Vitamin D₃ is degrading by current national drug standards when ultrasonic extraction in 75% dimethyl sulfoxide. That brings the larger RSD of sample determination results. The method is accurate and reliable about shaking the samples of calcium carbonate and vitamin D₃ preparations. The suggestion is to amend the method in current standards as ‘add 20 mL of 75% dimethyl sulfoxide to the powder of the preparation， and shake at 45 ℃ for 15 min， then take it cool’.