Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany.
Nutrients. 2021 Apr 22;13(5):1408. doi: 10.3390/nu13051408.
Meta-analyses of randomized controlled trials (RCTs) have demonstrated a protective effect of vitamin D (cholecalciferol) supplementation against cancer mortality. In the VITAL study, a RCT including 25,871 men ≥ 50 years and women ≥ 55 years, protective effects of vitamin D supplementation (2000 IU/day over a median of 5.3 years) with respect to incidence of any cancer and of advanced cancer (metastatic cancer or cancer death) were seen for normal-weight participants but not for overweight or obese participants. We aimed to explore potential reasons for this apparent variation of vitamin D effects by body mass index. We conducted complementary analyses of published data from the VITAL study on the association of body weight with cancer outcomes, stratified by vitamin D supplementation. Significantly increased risks of any cancer and of advanced cancer were seen among normal-weight participants compared to obese participants in the control group (relative risk (RR), 1.27; 95% confidence interval (CI), 1.07-1.52, and RR, 1.44; 95% CI, 1.04-1.97, respectively). No such patterns were seen in the intervention group. Among those with incident cancer, vitamin D supplementation was associated with a significantly reduced risk of advanced cancer (RR, 0.86; 95% CI, 0.74-0.99). The observed patterns point to pre-diagnostic weight loss of cancer patients and preventive effects of vitamin D supplementation from cancer progression as plausible explanations for the body mass index (BMI)-intervention interactions. Further research, including RCTs more comprehensively exploring the potential of adjuvant vitamin D therapy for cancer patients, should be pursued with priority.
对随机对照试验（RCT）的荟萃分析表明，维生素 D（胆钙化醇）补充剂具有预防癌症死亡的作用。在 VITAL 研究中，一项包括 25871 名年龄≥50 岁的男性和年龄≥55 岁的女性的 RCT 中，维生素 D 补充剂（中位数为 5.3 年，每天 2000IU）对正常体重参与者的任何癌症和晚期癌症（转移性癌症或癌症死亡）的发病率具有保护作用，但对超重或肥胖参与者则没有。我们旨在通过体重指数探索维生素 D 作用这种明显差异的潜在原因。我们对 VITAL 研究中关于体重与癌症结局的关系的已发表数据进行了补充分析，这些数据按维生素 D 补充剂进行分层。与对照组中的肥胖参与者相比，正常体重参与者的任何癌症和晚期癌症的风险显著增加（相对风险（RR），1.27；95%置信区间（CI），1.07-1.52，RR，1.44；95%CI，1.04-1.97）。干预组中没有出现这种模式。在发生癌症的患者中，维生素 D 补充剂与晚期癌症的风险显著降低相关（RR，0.86；95%CI，0.74-0.99）。观察到的模式表明，癌症患者的预诊断体重减轻和维生素 D 补充剂对癌症进展的预防作用是体重指数（BMI）-干预相互作用的合理解释。应优先进行进一步的研究，包括更全面地探索辅助维生素 D 治疗癌症患者的潜在可能性的 RCT。
