Italy: A recent study published in the journal Nutrients demonstrated an association between vitamin D levels and cognitive decline, irrespective of frailty status in community-dwelling older persons investigated for a suspected cognitive impairment.
Vitamin D appears to have a role in brain development, in the maintenance of cognitive abilities, and in frailty. Several studies have evaluated the interactions between vitamin D and cognitive impairment, the results however have been conflicting. Considering this, Beatrice Arosio, University of Milan, Milan, Italy, and colleagues described the association between vitamin D levels and cognitive decline and all-cause dementia evaluating frailty's contribution.

The study cohort included aged 64–92 years: 176 patients with mild cognitive impairment (MCI), 133 with mixed dementia (MD), 115 without cognitive decline, 59 with Alzheimer's Disease (AD), and 26 with idiopathic Normal Pressure Hydrocephalus (iNPH). Frailty was measured by frailty index, and electrochemiluminescence immunoassays were used to measure serum 25-hydroxyvitamin D concentrations.
The research yielded the following findings:
A significant association was found 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 this study, we observed an association between vitamin D levels and cognitive decline, regardless of frailty status, age and gender, in a cohort of community-dwelling older persons not taking vitamin D supplementation investigated for a suspected cognitive decline," the researchers wrote in their study.
One limitation of the study was that the MD patients were older, less literate, and frailer compared to the other groups. To compensate, the results were adjusted by age and FI.
Reference:
Arosio B, Rossi PD, Ferri E, Cesari M, Vitale G. Characterization of Vitamin D Status in Older Persons with Cognitive Impairment. Nutrients. 2022 Mar 8;14(6):1142. doi: 10.3390/nu14061142. PMID: 35334800.
KEYWORDS: vitamin D, cognitive impairment, older people, Beatrice Arosio, cognition, dementia, supplementation, supplements, Nutrients journal, aging, frailty, cognitive decline