Vitamin D Status and Intakes and Their Association With Cognitive Trajectory in a Longitudinal Study of Urban Adults.

CONTEXT

Serum 25-hydroxyvitamin D [25(OH)D], and dietary and supplemental vitamin D may influence cognitive outcomes.

OBJECTIVES

Sex-, age-, and race-specific associations of vitamin D status and intake with longitudinal change in various cognitive domains were examined in a large sample of ethnically and socioeconomically diverse US urban adults.

DESIGN

Two prospective waves of data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study were used.

PARTICIPANTS

Adults in Baltimore, Maryland, aged 30 to 64 years at baseline (n = 1231 to 1803), were followed for a mean (± standard deviation) of 4.64 ± 0.93 years. Visit 1 occurred between 2004 and 2009; visit 2, between 2009 and 2013; there were 1.5 to 2.0 visits per participant.

MAIN OUTCOME AND EXPOSURE MEASURES

Cognitive performance was assessed using 11 test scores covering domains of global cognition, attention, learning/memory, executive function, visuospatial/visuoconstruction ability, psychomotor speed, and language/verbal. Serum 25(OH)D, vitamin D intake, and use of supplements containing vitamin D were the key exposures.

RESULTS

A consistent relationship was found between vitamin D status (overall) and supplemental intake (older women and black adults), with a slower rate of decline in the domain of verbal fluency. Higher dietary intake of vitamin D was linked to slower rate of decline in verbal memory among younger women, and a slower rate of decline in visual memory/visuoconstructive abilities among white adults. All other associations were inconsistent.

CONCLUSIONS

Vitamin D status and intakes were inversely related to domain-specific cognitive decline in US urban adults.