目的：比较两种市售口服碳酸钙维生素Ｄ制剂［凯思立Ｄ３片（ＣａＤ３）和钙尔奇Ｄ片（ＣａＤ）］的人体相对生物利用度。方法：８名健康志愿者随机分为两组，自身交叉单剂量口服ＣａＤ３片（含５００ｍｇ元素钙及维生素Ｄ３２００ｕ）和ＣａＤ片（含６００ｍｇ元素钙及维生素Ｄ３１２５ｕ）各一片。收集口服两钙剂前３ｄ及口服后２４ｈ尿量，用原子吸收光谱法测定尿中钙含量。结果：口服两钙剂前３ｄ的２４ｈ尿钙总量均值（基础尿钙值）分别为（１１８．５９±４１．１５）ｍｇ和（１３４．６４±５９．５０）ｍｇ；口服两钙剂后２４ｈ尿钙总量分别为（１９８．８８±５４．９９）ｍｇ和（２１８．９２±８９．７６）ｍｇ，均高于基础尿钙值。经剂量校正后，ＣａＤ３片和ＣａＤ片之相对生物利用度为（１１１．４８±１８．６９）％。上述参数之间均无显著性差异。结论：尽管ＣａＤ３片和ＣａＤ片的元素钙及维生素Ｄ３含量不等，但二者人体生物利用度相近 OBJECTIVE: To compare the relative bioavailability of two commercially available oral calcium carbonate vitamin D preparations (Ca-D3 and Ca-D). Methods: Eight healthy volunteers were randomly divided into two groups: one crossover single oral dose of CaD3 tablets (containing 500mg elemental calcium and vitamin D3200u) and CaD tablets (containing 600mg elemental calcium and vitamin D3125u). Collect the amount of urinary calcium before oral administration of two doses of calcium and 24h after oral administration, and determine the content of calcium in urine by atomic absorption spectrometry. Results: The total urinary calcium values ​​(baseline urinary calcium values) were (118.59 ± 41.15) mg and (134.64 ± 59.50) mg, respectively, three days before oral administration of two calcium agents. After oral administration of two calcium agents The total amount of 24-hour urinary calcium was (198.88 ± 54.99) mg and (218.92 ± 89.76) mg, respectively, higher than the baseline urinary calcium. After dose correction, the relative bioavailability of Ca-D3 and Ca-D tablets was (111.48 ± 18.69)%. There is no significant difference between the above parameters. Conclusion: Although Ca-D3 tablets and Ca-D tablets have different contents of calcium and vitamin D3, their bioavailability is similar