Grant William B, Tangpricha Vin
Dermatoendocrinol. 2012 Apr 1;4(2):81-3. doi: 10.4161/derm.20435.
Evidence that vitamin D reduces the risk of many types of disease is increasing exponentially. In 2011, 3,100 publications with "vitamin D" in the title or abstract were published, up from 2,606 in 2010, 1,303 in 2005, and 796 in 2000. A committee operating under the auspices of the Institute of Medicine (IOM) of the US National Academies reviewed the evidence for beneficial effects of vitamin D. Their report, issued at the end of 2010,(1) found what they considered to be strong evidence for only one health outcome: skeletal health. They considered beneficial evidence only from published randomized controlled trials (RCTs) focused mainly on skeletal health. In contrast, to justify concern about higher vitamin D intake and serum 25(OH)D concentrations, they used data from nested case-control studies reporting U-shaped outcomes of prediagnostic serum 25-hydroxyvitamin D [25(OH)D] for cancer and all-cause mortality rates. They set the daily recommended intake of vitamin D at 600-800 IU for most children and adults and defined vitamin D sufficiency as a serum 25(OH)D level above 20 ng/ml (50 nmol/l). They also set a daily upper intake of 4,000 IU of vitamin D(3) and called for more RCTs to determine nonskeletal health effects. As of this writing, more than 130 journal publications have criticized the IOM report as being too conservative. One summarized the problems succinctly: "The IOM recommendations for vitamin D fail in a major way on logic, on science, and on effective public health guidance. Moreover, by failing to use a physiological referent, the IOM approach constitutes precisely the wrong model for development of nutritional policy."(2).
维生素D能降低多种疾病风险的证据正呈指数级增长。2011年，标题或摘要中含有“维生素D”的出版物有3100种，高于2010年的2606种、2005年的1303种以及2000年的796种。美国国家科学院医学研究所（IOM）主持的一个委员会审查了维生素D有益作用的证据。他们在2010年底发布的报告(1)发现，他们认为只有一项健康结果有强有力的证据：骨骼健康。他们仅考虑主要关注骨骼健康的已发表随机对照试验（RCT）中的有益证据。相比之下，为了证明对更高维生素D摄入量和血清25(OH)D浓度的担忧是合理的，他们使用了巢式病例对照研究的数据，这些研究报告了癌症和全因死亡率的诊断前血清25-羟基维生素D [25(OH)D]呈U形结果。他们将大多数儿童和成年人的维生素D每日推荐摄入量设定为600 - 800国际单位，并将维生素D充足定义为血清25(OH)D水平高于20纳克/毫升（50纳摩尔/升）。他们还设定了维生素D(3)的每日摄入量上限为4000国际单位，并呼吁进行更多的随机对照试验以确定非骨骼健康影响。截至撰写本文时，已有130多篇期刊文章批评IOM的报告过于保守。其中一篇简洁地总结了这些问题：“IOM关于维生素D的建议在逻辑、科学和有效的公共卫生指导方面都存在重大缺陷。此外，由于未使用生理参考标准，IOM的方法恰恰构成了营养政策制定的错误模式。”(2)
