Midlife dietary vitamin D intake and subsequent performance in different cognitive domains

We evaluated the cross-time association between midlife dietary vitamin D intake and subsequent cognitive performance in a French general-population sample.

Data from participants in both the SU.VI.MAX trial (1994-2002) and the SU.VI.MAX 2 observational study (2007-2009) were used. Dietary intake was estimated at baseline from 6 or more 24-hour records. Cognitive performance was evaluated 13 years later with a comprehensive neuropsychological battery. Parameter estimates of cognitive performance according to quartiles (Q) of vitamin D intake were estimated via ANCOVA.

In a sample of 1,990 aging adults, principal component analyses yielded two cognitive factors - for episodic/semantic memory and short-term memory/executive function; however, neither one displayed associations with dietary vitamin D intake. Midlife vitamin D intake was significantly and positively associated with scores on the forward digit span task measuring short-term memory (fully adjusted model: mean difference, Q4 vs. Q1 = 1.95; 95% CI 0.37-3.53; p(trend) = 0.03). No significant interaction with either sex or lifetime sun exposure was found.

Midlife vitamin D intake exhibited a cross-time and domain-specific association with cognition in the context of aging. Further investigations in this area of prevention are warranted given the rapidly expanding elderly population and the absence of curative treatment for dementia.