Vieth Reinhold
Department of Nutritional Sciences, and Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
Anticancer Res. 2022 Oct;42(10):5027-5034. doi: 10.21873/anticanres.16011.
Official public health pronouncements about sun exposure and vitamin D can be summarized as follows: First, there is no such thing as a safe tan. Therefore, avoid exposing the skin to sunshine. Second, in the absence of sunshine, a daily intake of 800 IU/day (20 mcg/d) vitamin D or less is sufficient for the health needs of almost all members of the population. However, exposure of the skin to sunlight induces multiple mechanisms that lower blood pressure, while also initiating production of vitamin D, which is needed to produce a hormone that regulates multiple systems including the cellular biology that affects cancer mortality. Disease-prevention relationships point to a beneficial threshold for serum 25-hydroxyvitamin D [25(OH)D; the index of vitamin D nutrition] that is at least 75 nmol/l (30 ng/ml). To ensure the threshold for all adults, an average per-day minimum total input of vitamin D3 from sunshine/UVB exposure, and/or from food (natural food like fish or fortified food like milk), and/or vitamin supplementation of at least 4,000 IU/d (100 mcg/d) is required. Strong, although not Level-1, evidence indicates that the maintenance of that threshold will lower mortality overall, lower mortality from cancer, and lower the risk of certain other diseases such as respiratory infection and COVID-19.
官方关于阳光照射与维生素D的公共卫生声明可总结如下：首先，不存在安全的晒黑这回事。因此，应避免皮肤暴露于阳光下。其次，在缺乏阳光照射的情况下，几乎所有人群的健康需求每日摄入800国际单位/天（20微克/天）或更低剂量的维生素D就足够了。然而，皮肤暴露于阳光下会引发多种降低血压的机制，同时还会启动维生素D的生成，而维生素D是生成一种调节多个系统（包括影响癌症死亡率的细胞生物学）的激素所必需的。疾病预防关系表明，血清25-羟基维生素D[25(OH)D；维生素D营养指标]的有益阈值至少为75纳摩尔/升（30纳克/毫升）。为确保所有成年人达到该阈值，每天从阳光/紫外线B照射、和/或食物（如鱼类等天然食物或牛奶等强化食品）、和/或维生素补充剂中获得的维生素D3的平均最低总摄入量至少需要4000国际单位/天（100微克/天）。有力的证据（尽管不是一级证据）表明，维持该阈值将降低总体死亡率、降低癌症死亡率，并降低某些其他疾病（如呼吸道感染和新冠病毒病）的风险。
