HealthDay News — For ethnically diverse older adults, low vitamin D status is associated with accelerated decline in cognitive function, according to a study published online in JAMA Neurology.
Joshua W. Miller, PhD, from Rutgers University in New Brunswick, New Jersey, and colleagues examined the correlation between vitamin D status and trajectories of change in subdomains of cognitive function in a cohort of 382 ethnically diverse older adults (41.4% white, 29.6% African-American, 25.1% Hispanic, and 3.9% other race/ethnicity).
The researchers found that the mean 25-hydroxyvitamin D (25-OHD) level was 19.2 ng/mL; 26.2 and 35.1% of participants were vitamin D deficient and insufficient, respectively. Compared with white participants, the mean 25-OHD levels were significantly lower for African-American and Hispanic participants (21.7 versus 17.9 and 17.2 ng/mL, respectively). The dementia group had significantly lower mean 25-OHD compared with the mild cognitive impairment and cognitively normal groups, respectively (16.2 versus 20 and 19.7 ng/mL, respectively).
Vitamin D deficient and insufficient participants had greater rates of decline in episodic memory and executive function (vitamin D deficient: P = 0.49 and P = 0.01; vitamin D insufficient: P < 0.001 and P = 0.008) compared with those with adequate status, after adjustment for confounding variables.
“It remains to be determined whether vitamin D supplementation slows cognitive decline,” the authors write.
Miller JW, et al. Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults. JAMA Neurology. 2015; doi:10.1001/jamaneurol.2015.2115