The value of physiologic vitamin D as a biomarker of dementia.

Vitamin D has been investigated in association with cognitive function in healthy and multimorbid elderly patients. Whether higher physiologic concentrations of vitamin D may be neuroprotective is not yet known. Epidemiological investigations have suggested a protective effect of physiologic vitamin D concentrations (circulating 25-hydroxyvitamin D) on neurocognitive dysfunction and cerebrovascular disease. Recent prospective studies have shown a beneficial association of vitamin D with a myriad of health conditions and suggest that vitamin D may be neuroprotective via vascular mechanisms. Whether vitamin D concentrations are a useful indicator for the identification and clinical management of dementia remains to be determined. On its own, physiological vitamin D status may be an important risk indicator for several comorbidities; however, further studies are required to determine if physiological vitamin D can be used as a biomarker in the clinical determination and disease management of dementia.