为评估维生素D3补充对一般人群的癌症死亡率和癌症患者预后的影响，进行了一项随机、安慰剂对照试验（RCT）和个体病人数据（IPD）的系统回顾及荟萃分析。总共鉴定了14个RCT，共计104727名参与者（2015名癌症死亡），其中7个RCT（包括所有研究参与者的90％（n = 94068）），可纳入IPD荟萃分析。14个RCT的主要荟萃分析表明癌症死亡率降低了6％，但统计学上无显著性（风险比（RR）[95%CI]：0.94 [0.86-1.02]）。亚组分析显示，在每天剂量方案中使用维生素D3组与安慰剂组相比，癌症死亡率降低了12％的10个试验（RR [95%CI]：0.88 [0.78-0.98]），而使用大剂量补充的4个试验未观察到死亡风险降低（RR [95%CI]：1.07 [0.91-1.24]；相互作用的p值为0.042）。IPD荟萃分析（RR [95%CI]：0.93 [0.84; 1.02]）确认了所有试验的结果。IPD用于测试年龄，性别，体重指数，种族，基线血清25-羟基维生素D浓度，依从性和与癌症有关的因素的影响，但在所有试验的荟萃分析中未得到统计学上显著的结果。但在后续分析的每日服用试验中，年龄≥70岁的成年人（RR [95%CI]：0.83 [0.77; 0.98]）和在癌症诊断之前开始维生素D3治疗的病人（RR [95%CI]：0.87 [0.69; 0.99]）似乎最受益于每日维生素D3补充。由于试验中基线25-羟基维生素D水平的测量和非非西班牙裔白人成人的纳入过于稀少，因此无法得出结论。对于癌症患者的总体存活率和癌症特异性存活率，与一般人群的癌症死亡率相似。总之，在所有RCT的主要荟萃分析中，维生素D3并没有降低癌症死亡率，因为观察到的6％风险降低没有统计学上的显著性。然而，亚组分析显示，相比于一次性使用，每天口服维生素D3可将癌症死亡率降低12％。版权所有 © 2023 Elsevier B.V.。

To evaluate the effect of vitamin D3 supplementation on cancer mortality in the general population and on prognosis in cancer patients, a systematic review and meta-analysis of randomised, placebo-controlled trials (RCTs) and individual patient data (IPD) was conducted. Overall, 14 RCTs with a total of 104,727 participants (2,015 cancer deaths) were identified and 7 RCTs, including 90% of all study participants (n=94,068), could be included in the IPD meta-analyses. The main meta-analysis of the 14 RCTs yielded a statistically non-significant reduction in cancer mortality by 6% (risk ratio (RR) [95%-confidence interval (95%CI)]: 0.94 [0.86-1.02]). Subgroup analyses revealed a 12% lower cancer mortality in the vitamin D3 group compared with the placebo group in 10 trials with a daily dosing regimen (RR [95%CI]: 0.88 [0.78-0.98]), whereas no mortality reduction was seen in 4 trials using a bolus regimen (RR [95%CI]: 1.07 [0.91-1.24]; p-value for interaction: 0.042). The IPD meta-analysis (RR [95%CI]: 0.93 [0.84; 1.02]) confirmed the finding of all trials. The IPD were used to test effect modification by age, sex, body mass index, ethnicity, baseline serum 25-hydroxyvitamin D concentration, adherence and cancer-related factors but no statistically significant findings were obtained in meta-analyses of all trials. When restricted to trials with daily dosing in a post-hoc analysis, adults aged ≥70 years (RR [95%CI]: 0.83 [0.77; 0.98]) and subjects with vitamin D3 therapy initiation before cancer diagnosis (RR [95%CI]: 0.87 [0.69; 0.99]) appeared to benefit most from daily vitamin D3 supplementation. Measurements of baseline 25-hydroxyvitamin D levels and inclusion of other than non-Hispanic White adults were too sparse in the trials to draw conclusions. Results for all-cause and cancer-specific survival of participants with cancer were comparable to those obtained in the general population for cancer mortality. In conclusion, vitamin D3 did not reduce cancer mortality in the main meta-analysis of all RCTs because the observed risk reduction by 6% was not statistically significant. However, a subgroup analysis revealed that vitamin D3 administered daily, in contrast to bolus supplementation, reduced cancer mortality by 12%.Copyright © 2023 Elsevier B.V. All rights reserved.