Vitamin D deficiency and cognitive decline
Tuesday, 29 September 2015
Over the past few years there has been a huge amount of research into vitamin D deficiency. Although we are all aware of the current recommendations regarding vitamin D, the vast majority of children under the age of 5 that I know (either as patients or as friends’ children) are not taking any vitamin D.
We all know that having low vitamin D levels is associated with osteomalacia and rickets. It is also associated with various respiratory diseases and also some types of cancer.
An interesting study* recently published in JAMA Neurology has shown that a low vitamin D concentration is associated with a more rapid decline in cognitive function among older adults.
Although the majority of people in this study actually had low levels of vitamin D, the mean vitamin D concentration was significantly lower in those with dementia than in those with mild cognitive impairment and those who were cognitively normal.
In addition, those people who were vitamin D deficient or vitamin D insufficient had greater rates of cognitive decline compared to those with normal vitamin D levels.
However, what this study did not answer (which is really the most important question) is: does vitamin D supplementation actually slows cognitive decline?
* Joshua W. Miller, et al. Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults. JAMA Neurol. Published online 14 September 2015. doi:10.1001/jamaneurol.2015.2115