Vitamin D and the Aging Brain

A year ago we had a report of an association between the blood level of vitamin D and cognitive function.  That was a UK study with patient data from 8 European countries.  A still earlier study from China had shown a similar association.  And now there’s a study from the USA that was published in the Journals of Geriatrics late last year.  It was done at Tufts University, Boston.  

Serum 25(OH)D levels and cognitive function were measured in more than 1,000 over-65-year-olds, who were receiving home care.  Cognitive function was measured by a battery of selected neuropsychological tests.

 Over 65% of the participants had suboptimal levels of 25(OH)D, i.e. below 20 ng/mL.  About 17% had clear-cut deficiency – below 10 ng/ml.  Analyses were done that took into account differences in age, gender, race, body mass index (BMI), education level, kidney function, physical activity, alcohol use, seasonality of sampling, and the home center.  The levels of 25(OH)D were linked with better performance on two trail-making tests, digit symbols, matrix reasoning, and block design.  Further adjustments were made for individual differences in blood homocysteine, the apoE4 genotype, plasma vitamin B levels, and multivitamin use; again, the 25(OH)D levels were linked with better results on the 5 tests.  Memory tests were not linked in this way, but measures of ‘executive function’ (cognitive flexibility, perceptual complexity, and reasoning) were better in the 65% of participants with adequate vitamin D levels.  That ought to be enough for you to make sure you are getting enough vitamin D, either in your food, or as a supplement, or from plenty of sunshine.