"Vitamin D and Cognitive Function: Descriptive Review of the Scientific Evidence"

Abstract

Introduction: Considerable amounts of vitamin D are found in the brain and the vitamin D receptor is widely distributed throughout various brain regions. The effects of vitamin D on the regulation of genes involved in neuroprotection and neurotropism or neuronal regeneration have been described. There is a high prevalence of vitamin D deficiency or insufficiency among the elderly. The aim of this article is to review the relationship between vitamin D and cognition. We have attempted to answer three questions: Is there a physiological rationale that allows us to conclude that vitamin D has cognitively relevant effects? Is hypovitaminosis D associated with cognitive impairment? Does vitamin D supplementation have any effect on cognitive impairment or dementia? Development: A descriptive review has been conducted on the research that we have considered to be the most relevant published in the last decade: cross-sectional, prospective, and retrospective studies, and randomized placebo-controlled trials have been included. Conclusions:Preclinical studies show wide proof of concept that vitamin D may play a relevant role in cognitive functions. There is no consensus on the association of hypovitaminosis D and cognitive impairment, although most studies have found such an association. There is also no conclusive scientific evidence on beneficial effects of vitamin D supplementation on cognitive impairment, although the positive evidence available -mainly with cholecalciferol or vitamin D3 as preferred vitamin D form-is leading many authors and some clinicians to recommend it in usual practice. on vitamin D supplementation in this context and points out