Constans Thierry, Mondon Karl, Annweiler Cédric, Hommet Caroline
Service de médecine interne gériatrique, Hôpital Bretonneau, CHU de Tours et Université François Rabelais, Tours.
Psychol Neuropsychiatr Vieil. 2010 Dec;8(4):255-62. doi: 10.1684/pnv.2010.0233.
The understanding of the role of vitamin D in maintaining good health has considerably increased in the recent years. There is a growing evidence that vitamin D has not only a beneficial effect to prevent osteoporosis and the risk of falls in the elderly, but also may reduce incidence of cancers, infections, autoimmune, cardiovascular and neurologic diseases, and psychiatric disorders. Laboratory studies yield a biological plausibility for a positive contribution of vitamin D to brain functions: vitamin D receptor and 1,α-hydroxylase, the terminal calcitriol-activating enzyme, are widely distributed in both the fetal and adult brain. Vitamin D may be involved in neuroprotection, control of proinflammatory cytokine induced cognitive dysfunction and synthesis of calcium-binding proteins and neurotransmitter acetylcholine. However, the observational studies conducted in humans are still inconclusive, given the various tests of the cognitive functions that have been used, the performance of the studies either in patients or in healthy subjects, and different designs and/or confounding factors. The role of the vitamin D receptor in the pathophysiology of cognitive decline, incidence of Alzheimer's disease or vascular dementia and/or cognitive decline with respect to previous plasma 25OHD concentration, and the effect on cognition of vitamin D supplementation should be explored in further studies.
近年来，人们对维生素D在维持身体健康方面的作用的认识有了显著提高。越来越多的证据表明，维生素D不仅对预防老年人的骨质疏松症和跌倒风险有有益作用，而且还可能降低癌症、感染、自身免疫性疾病、心血管疾病、神经系统疾病和精神障碍的发病率。实验室研究为维生素D对脑功能的积极贡献提供了生物学合理性：维生素D受体和1α-羟化酶（维生素D3的终末活化酶）在胎儿和成人脑中均广泛分布。维生素D可能参与神经保护、控制促炎细胞因子诱导的认知功能障碍以及钙结合蛋白和神经递质乙酰胆碱的合成。然而，鉴于所使用的各种认知功能测试、在患者或健康受试者中开展的研究、不同的设计和/或混杂因素，在人类中进行的观察性研究仍无定论。维生素D受体在认知功能下降的病理生理学、阿尔茨海默病或血管性痴呆的发病率以及相对于既往血浆25羟维生素D浓度的认知功能下降中的作用，以及维生素D补充剂对认知的影响，应在进一步研究中加以探索。
