Posted on Mon, 10 Apr 17
Vitamin D deficiency is a wide-spread problem and has been linked to cognitive impairment and dementia. A new clinical study suggests that improving vitamin D levels could help.
Several studies have found associations between vitamin D deficiency and impaired cognitive function including memory, as well as an important increase in risk for developing Alzheimer's disease.
Vitamin D plays an important role in neurological function, which helps explain these observations.
However, according to the author of a new study, Dr. Jacqueline Pettersen from the University of British Columbia, the few studies that have assessed the effects of vitamin D supplementation on cognitive function are limited by methodological problems such as insufficient dose, using inferior vitamin D2 instead of D3, and not controlling for vitamin D deficiency at baseline.
To help clarify whether or not vitamin D supplementation could improve memory a group of otherwise healthy adults were supplemented with a high (4000 IU/ daily) or low dose (400 IU/ daily) of vitamin D3 for 18-weeks.
Over the study duration blood vitamin D levels increased to a mean level up to 130 nmol/L in the high dose group and 85.9 nmol/L in the low dose group.
The higher dose of vitamin D resulted in improvement in aspects (visuospatial) of memory, and this benefit appeared to be more pronounced among those who were vitamin D deficient at the beginning of the study.
“These findings are consistent with recent observational studies demonstrating significant positive associations between blood vitamin D (25(OH)D) levels and nonverbal, but not verbal memory, and may relate to the increased cognitive demands and reliance on executive functioning processes that visual memory requires,” commented Dr Petterson.
“While the optimal level of vitamin D for bone health has been cited as 75 nmol/L (>30 ng/ml) or higher, the optimal level for cognition is not known. These findings suggest that higher levels may be better, at least for learning and memory tasks involving nonverbal information.”
Pettersen JA. Does high dose vitamin D supplementation enhance cognition?: A randomized trial in healthy adults. Exp Gerontol. 2017 Apr;90:90-97.