Grant William B, Karras Spyridon N, Bischoff-Ferrari Heike A, Annweiler Cedric, Boucher Barbara J, Juzeniene Asta, Garland Cedric F, Holick Michael F
Sunlight, Nutrition, and Health Research Center San Francisco , CA, USA.
Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki , Thessaloniki, Greece.
Dermatoendocrinol. 2016 May 16;8(1):e1187349. doi: 10.1080/19381980.2016.1187349. eCollection 2016 Jan-Dec.
Several reports describe U-shaped 25-hydroxyvitamin D [25(OH)D] concentration-health outcomes, including musculo-skeletal disorders such as falls and fractures, several cancers, cardiovascular disease (CVD), cognitive function, all-cause mortality rates, birth outcomes, allergic reactions, frailty, and some other disorders. This paper reviews reports of U-shaped outcome associations with vitamin D status for evidence of underlying pathophysiological processes, or of confounding, finding that some U-shaped associations appear to be biologically meaningful, but that many could well reflect confounding by factors such as lifestyle, or hypovitaminosis D-related disease onset being masked by self-supplementation that was begun too late to correct developing health problems but before baseline vitamin D status assessment. However, the various U-shaped associations for allergic reactions may be due to vitamin D modulation of the phenotype of the immune response, shifting the Th1-Th2 balance toward Th2 formation. For prostate cancer, there seems to be little effect of 25(OH)D concentration on incidence; however, there is an inverse correlation between 25(OH)D concentration and mortality rates. Future observational studies, and randomized controlled trial data analyses, should include adjustment for data collected on prior long-term vitamin D supplementation and solar UVB exposure, as well as other potential confounders.
几份报告描述了25-羟基维生素D[25(OH)D]浓度与健康结局的关系，包括肌肉骨骼疾病，如跌倒和骨折、几种癌症、心血管疾病（CVD）、认知功能、全因死亡率、出生结局、过敏反应、虚弱以及其他一些疾病。本文回顾了关于维生素D状态与结局呈U型关联的报告，以寻找潜在病理生理过程或混杂因素的证据，发现一些U型关联似乎具有生物学意义，但许多可能很好地反映了诸如生活方式等因素的混杂作用，或者维生素D缺乏相关疾病的发病被自我补充所掩盖，这种补充开始得太晚，无法纠正正在发展的健康问题，但在基线维生素D状态评估之前。然而，过敏反应的各种U型关联可能是由于维生素D对免疫反应表型的调节，使Th1-Th2平衡向Th2形成方向转变。对于前列腺癌，25(OH)D浓度对发病率似乎影响不大；然而，25(OH)D浓度与死亡率之间存在负相关。未来的观察性研究以及随机对照试验数据分析，应包括对先前长期维生素D补充和太阳紫外线B暴露以及其他潜在混杂因素所收集数据的调整。
