Vitamin D is usually associated with bone health, but it seems to affect brain function too. Results from the US national HANES III study of 3325 adults aged over 65 years examined brain function for impairment of cognitive function. Vitamin D levels in blood samples were also measured.

Compared with those with normal vitamin D levels, the study participants who were very deficient in the vitamin were six times more likely to have developed cognitive decline; after correction for numerous other factors, the risk was still increased at least four-fold. Even those mildly deficient in the vitamin had a two-fold greater risk.

The effect was found to be least for actual memory function, which explains why perhaps the realtionship was missed before. Whether this effect can be slowed by vitamin D supplementation is being studied.

A similar result was reported by another study in Italy. For this report, an editorial questioned whether the effect was simply due to poor diet and other factors such as inadequate sunlight exposure.

Sources: Llewellyn DJ, et al. Paper presented at the Alzheimers International Meeting 2010; and Llewellyn DJ et al. Arch Intern Med 2010; 170: 1135-41.

More nutrition research news

Originally posted in August 2010. everybody Nutrition News items are selected from a wide range of journals, bulletins and nutrition information sources worldwide and summarised by Professor John Birkbeck, Institute of Food Nutrition and Human Health, Massey University. The opinions contained herein are those of the author and not necessarily those of the publisher or sponsor. Copyright UBM Medica (NZ) Ltd.