Ann Intern Med. 2013 Dec 17;159(12):824-34. doi: 10.7326/0003-4819-159-12-201312170-00729.
Vitamin and mineral supplements are commonly used to prevent chronic diseases.
To systematically review evidence for the benefit and harms of vitamin and mineral supplements in community-dwelling, nutrient-sufficient adults for the primary prevention of cardiovascular disease (CVD) and cancer.
MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were searched from January 2005 to 29 January 2013, with manual searches of reference lists and gray literature.
Two investigators independently selected and reviewed fair- and good-quality trials for benefit and fair- and good-quality trials and observational studies for harms.
Dual quality assessments and data abstraction.
Two large trials (n = 27 658) reported lower cancer incidence in men taking a multivitamin for more than 10 years (pooled unadjusted relative risk, 0.93 [95% CI, 0.87 to 0.99]). The study that included women showed no effect in that group. High-quality studies (k = 24; n = 324 653) of single and paired nutrients (such as vitamins A, C, or D; folic acid; selenium; or calcium) were scant and heterogeneous and showed no clear evidence of benefit or harm. Neither vitamin E nor β-carotene prevented CVD or cancer, and β-carotene increased lung cancer risk in smokers.
The analysis included only primary prevention studies in adults without known nutritional deficiencies. Studies were conducted in older individuals and included various supplements and doses under the set upper tolerable limits. Duration of most studies was less than 10 years.
Limited evidence supports any benefit from vitamin and mineral supplementation for the prevention of cancer or CVD. Two trials found a small, borderline-significant benefit from multivitamin supplements on cancer in men only and no effect on CVD.
Agency for Healthcare Research and Quality.
维生素和矿物质补充剂常用于预防慢性病。
系统评价社区中营养充足的成年人使用维生素和矿物质补充剂预防心血管疾病（CVD）和癌症的主要益处和危害的证据。
从 2005 年 1 月至 2013 年 1 月 29 日，检索 MEDLINE、Embase、Cochrane 对照试验中心注册库、Cochrane 系统评价数据库和效应摘要数据库，同时手动检索参考文献和灰色文献。
两位研究者独立选择并评价了益处的高质量试验和危害的高质量试验和观察性研究。
双重质量评估和数据提取。
两项大型试验（n = 27658）报告了男性服用多种维生素超过 10 年时癌症发病率降低（汇总未调整的相对风险，0.93 [95%CI，0.87 至 0.99]）。包括女性的研究未显示出该组的效果。高质量的单一和配对营养素（如维生素 A、C 或 D；叶酸；硒；或钙）研究（k = 24；n = 324653）很少且异质，没有明确的获益或危害证据。维生素 E 和 β-胡萝卜素均不能预防 CVD 或癌症，且β-胡萝卜素增加了吸烟者的肺癌风险。
该分析仅包括无已知营养缺乏的成年人的一级预防研究。研究在老年人中进行，包括各种补充剂和设定的可耐受上限下的不同剂量。大多数研究的持续时间不到 10 年。
有限的证据支持维生素和矿物质补充剂预防癌症或 CVD 的任何益处。两项试验发现男性仅服用多种维生素补充剂对癌症有小的、边缘显著的益处，对 CVD 无影响。
医疗保健研究与质量局。
