According to a provocative report in JAMA Neurology, low vitamin D levels in the elderly may have dire consequences for intellectual function. For this evaluation researchers monitored the cognitive capacity of 382 racially diverse elderly men and women over a five-year study period. Each study subject also had his or her vitamin D blood levels measured at the beginning of the study period. Low levels of vitamin D at baseline were rampant, including 54% of the Caucasian study subjects and 70% of the Hispanics and African Americans.

The real eye-opener was this: relative to study subjects with adequate levels of vitamin D at baseline, those with deficient levels lost cognitive capacity up to three times more rapidly, particularly in the vitally important areas of memory and executive function. The authors of the study were struck both by how common low vitamin D levels were in older individuals, as well as how quickly and profoundly those with low D lost brain power.