Adequate vitamin D intake may improve cognitive function

A new French study suggests that regular dietary intake of vitamin D may be associated with an increased cognitive performance among older adults.

In the cohort study, a total of 5,596 women (mean age 80.5 years) were divided into two groups according to baseline weekly vitamin D dietary intake. Estimated from a self-administered food frequency questionnaire, the participants were classified as having either inadequate intake (<35 micrograms per week) or recommended intake (>35micrograms per week corresponding to >400 IU per day) (1). To examine a potential association between vitamin D intake and cognitive performance, cognitive impairment was measured with a questionnaire in both groups. The results showed that women with inadequate vitamin D intakes had more cognitive deficits than the participants with recommended intakes. The association remained significant even after adjusting for factors such as body mass index, sun exposure, number of chronic diseases, hypertension, depression, disability or use of antidepressants or other medications.

Researchers concluded that a regular, adequate intake of vitamin D is significantly associated with improved cognitive performance in elderly women. It has yet to be confirmed if this association is causal. They commented that only a few studies have examined the association between dietary vitamin D and improved cognition in a large population sample. Such studies are needed to clarify whether the associations reported in this study also exist in other populations. This would be a guide for future research as to whether or not to pursue large-scale clinical trials that examine the benefits of vitamin D supplementation to treat or prevent cognitive impairment.

Some previous studies have suggested that vitamin D supplementation may exert a beneficial effect on cognitive function among older adults, because vitamin D binds to neural receptors in the brain thereby acting towards neuroprotection with its anti-inflammatory and antioxidative effects. Other related research has shown an association between vitamin D deficiency and dementia, particularly Alzheimer’s disease, suggesting vitamin D deficiency to be a measurable and modifiable risk factor for potential cognitive decline (2, 3).

1. Annweiler C. et al. Dietary intake of vitamin D and cognition in older women: A large population-based study. Neurology. 2010; 75(20):1810–1816.
2. Buell J. S. et al. 25-Hydroxyvitamin D, dementia, and cerebrovascular pathology in elders receiving home services. Neurology. 2010; 74(1):18–26.
3. Pogge E. Vitamin D and Alzheimer's disease: is there a link? Consult Pharm. 2010; 25(7):440–450.