Ekmekcioglu Cem, Haluza Daniela, Kundi Michael
Department of Environmental Health, Center for Public Health, Medical University of Vienna, Kinderspitalgasse 15, Vienna A-1090, Austria.
Int J Environ Res Public Health. 2017 Jan 28;14(2):127. doi: 10.3390/ijerph14020127.
Epidemiological evidence suggests an association between low vitamin D status and risk for various outcomes including cardiovascular diseases, cancer, and type 2 diabetes mellitus (T2DM). Analyzing serum 25-hydroxyvitamin D [25(OH)D] is the most established means to evaluate an individual's vitamin D status. However, cutoff values for 25(OH)D insufficiency as well as for optimal 25(OH)D levels are controversial. This systematic review critically summarizes the epidemiological evidence regarding 25(OH)D levels and the risk for colorectal cancer and T2DM. The meta-analytical calculation revealed a pooled relative risk (RR) of 0.62 (CI 0.56-0.70; I² = 14.7%) for colorectal cancer and an RR of 0.66 (CI 0.61-0.73; I² = 38.6%) for T2DM when comparing individuals with the highest category of 25(OH)D with those in the lowest. A dose-response analysis showed an inverse association between 25(OH)D levels and RR for both outcomes up to concentrations of about 55 ng/mL for colorectal cancer and about 65 ng/mL for T2DM. At still higher 25(OH)D levels the RR increases slightly, consistent with a U-shaped association. In conclusion, a higher 25(OH)D status is associated with a lower risk for colorectal cancer and T2DM; however, this advantage is gradually lost as levels increase beyond 50-60 ng/mL.
流行病学证据表明，维生素D水平低下与包括心血管疾病、癌症和2型糖尿病（T2DM）在内的各种不良后果风险之间存在关联。分析血清25-羟基维生素D [25(OH)D] 是评估个体维生素D水平最常用的方法。然而，25(OH)D不足以及最佳25(OH)D水平的临界值存在争议。本系统评价批判性地总结了关于25(OH)D水平与结直肠癌和T2DM风险的流行病学证据。荟萃分析计算显示，将25(OH)D水平最高组的个体与最低组个体进行比较时，结直肠癌的合并相对风险（RR）为0.62（95%置信区间[CI] 0.56 - 0.70；I² = 14.7%），T2DM的RR为0.66（CI 0.61 - 0.73；I² = 38.6%）。剂量反应分析表明，在结直肠癌约55 ng/mL和T2DM约65 ng/mL的浓度范围内，两种结局的25(OH)D水平与RR均呈负相关。在更高的25(OH)D水平下，RR略有增加，与U形关联一致。总之，较高的25(OH)D水平与较低的结直肠癌和T2DM风险相关；然而，当水平超过50 - 60 ng/mL时，这种优势会逐渐丧失。
