Higher blood concentrations of vitamin D may reduce the risk of developing mild cognitive impairment, and the interplay between this nutrient and cholesterol levels, as well as the metabolism of cholesterols and lipids, could be relevant, the authors of a recent observational study appearing in the Journal of Nutrition found.
 
Mild cognitive impairment (MCI) is characterized as a transitional stage between a healthy mental state and age-related dementia. It is considered by researchers to be an area that has critical potential for diagnoses, intervention, prevention, and therapeutic interventions for Alzheimer’s disease.
 
The authors of the study recruited 209 MCI patients and 209 age- and gender-matched healthy controls, between the ages of 59 and 66. Serum concentrations of 25(OH)D, the metabolite of vitamin D, were measured, along with serum lipids and oxysterols, an oxygenated derivative of cholesterol which can pass through cell membranes and the blood-brain barrier.
 
The authors of the study found that participants with vitamin D deficiency were three times more likely to develop MCI compared to those with adequate vitamin D concentrations greater than 30 ng/mG. Of importance, vitamin D concentrations were negatively correlated with cholesterol, while cognitive test scores (the Montreal Cognitive Assessment and symbol digit modalities test) were higher among patients with higher vitamin D concentrations.
 
The authors of the study noted that vitamin D and cholesterol share common metabolic pathways. Further, a marker of vitamin D deficiency called cytochrome P450 27A1 has been previously shown to catalyze the conversion of cholesterol to an oxysterol known as 27-OHC.
 
In fact, the present study examined several oxysterols and found that they were correlated with MCI compared to the healthy control group, including 27-OHC, 4β-OHC, 24S,25-epoxy-CHO, and 24-OHC.
 
“These findings indicate that vitamin D supplementation may improve cognitive function by regulating cholesterol metabolism,” the authors of the study concluded. “These findings provide a basis of improving cognitive health and alleviating hypercholesterolemia.”