Better memory if take lots of vitamin D (senior rats) – May 2015

Vitamin D prevents cognitive decline and enhances hippocampal synaptic function in aging rats.

Proc Natl Acad Sci U S A. 2014 Oct 14;111(41):E4359-66. doi: 10.1073/pnas.1404477111. Epub 2014 Sep 29.
Latimer CS1, Brewer LD1, Searcy JL1, Chen KC1, Popović J1, Kraner SD2, Thibault O1, Blalock EM1, Landfield PW1, Porter NM3.

Vitamin D is an important calcium-regulating hormone with diverse functions in numerous tissues, including the brain. Increasing evidence suggests that vitamin D may play a role in maintaining cognitive function and that vitamin D deficiency may accelerate age-related cognitive decline. Using aging rodents, we attempted to model the range of human serum vitamin D levels, from deficient to sufficient, to test whether vitamin D could preserve or improve cognitive function with aging. For 5-6 mo, middle-aged F344 rats were fed diets containing low, medium (typical amount), or high (100, 1,000, or 10,000 international units/kg diet, respectively) vitamin D3, and hippocampal-dependent learning and memory were then tested in the Morris water maze. Rats on high vitamin D achieved the highest blood levels (in the sufficient range) and significantly outperformed low and medium groups on maze reversal, a particularly challenging task that detects more subtle changes in memory. In addition to calcium-related processes, hippocampal gene expression microarrays identified pathways pertaining to synaptic transmission, cell communication, and G protein function as being up-regulated with high vitamin D. Basal synaptic transmission also was enhanced, corroborating observed effects on gene expression and learning and memory. Our studies demonstrate a causal relationship between vitamin D status and cognitive function, and they suggest that vitamin D-mediated changes in hippocampal gene expression may improve the likelihood of successful brain aging.

PMID: 25267625
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