Characterization of Vitamin D Status in Older Persons with Cognitive Impairment.

Beatrice Arosio,Matteo Cesari,Evelyn Ferri,Giovanni Vitale,Paolo Dionigi Rossi

doi:10.3390/nu14061142

Abstract

Vitamin D exerts a role in the maintenance of cognitive abilities and in frailty. Although several studies evaluated the interactions between vitamin D and cognitive impairment, results were conflicting. In a cohort of community-dwelling older persons, we described the association between vitamin D levels and cognitive decline and all-cause dementia evaluating frailty’s contribution. Our cohort included 509 adults, aged 64–92 years: 176 patients with mild cognitive impairment (MCI), 59 with Alzheimer’s Disease (AD), 26 with idiopathic Normal Pressure Hydrocephalus (iNPH), 133 with mixed dementia (MD) and 115 without cognitive decline. Frailty was measured by frailty index, and serum 25-hydroxyvitamin D concentrations through electrochemiluminescence immunoassays. We found a significant association between vitamin D levels and Mini Mental State Examination independently of cognitive impairment, age, sex and frailty. The patients with dementia (AD and MD) showed the lowest vitamin D levels, while MCI patients showed higher levels than the other groups. The most severe deficiency was observed in MD patients, the most aged as well as cognitively and functionally impaired. In conclusion, in our community-dwelling older persons investigated for a suspected cognitive impairment, we observed an association between vitamin D levels and cognitive decline, regardless of the frailty status.

Highlights

Publisher’s Note: MDPI stays neutralAging induces changes in all body apparatus, including the remodeling of the endocrine system [1]
We found a significant association between vitamin D levels and Mini Mental State Examination independently of cognitive impairment, age, sex and frailty
In our community-dwelling older persons investigated for a suspected cognitive impairment, we observed an association between vitamin D levels and cognitive decline, regardless of the frailty status

Summary

Introduction

Aging induces changes in all body apparatus, including the remodeling of the endocrine system [1] This remodeling involves the parathyroid glands altering the production of the parathyroid hormone and of the secosteroid pro-hormone vitamin D [2]. A recent study reported that in a new mouse model the vitamin D receptor (VDR) is widely distributed into the brain cells [10,11] expressing the enzyme that converts the inactive vitamin D form into the active one [12]. This pathway makes the brain able to synthesize, catabolize and receive vitamin D, which regulates many cellular processes in neurons and microglial cells [12]. We have previously described with regard to jurisdictional claims in published maps and institutional affiliations

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