Vitamin D Deficiency Linked to Dementia, Alzheimer's Disease

Adding to the ongoing debate surrounding vitamin D’s effects, University of Exeter Medical School researchers reported vitamin D deficiency was strongly associated with Alzheimer’s disease and dementia development.

In a study published online in Neurology, investigators analyzed the medical records of 1,658 individuals aged 65 or over who were enrolled in the Cardiovascular Health Study.Candidates who had dementia, cardiovascular disease and stroke were eliminated from the study. Blood samples quantifying vitamin D levels were taken during 1992-1993.

During follow-up, the researchers discovered 171 and 102 participants had developed dementia and Alzheimer’s disease, respectively. Persons with low concentrations of vitamin D were 53% more likely to develop any kind dementia. For individuals with a severe vitamin D deficiency, their likelihood of getting dementia surged to 125%.

The results were similar for Alzheimer’s disease, with a 69% and 122% increased chance in persons that had low and extremely low vitamin D, respectively.

Overall, the writers confirmed that vitamin D levels above 50 nmol/L had the strongest association with positive brain development.

In a statement released by the University of Exeter Medical School, lead author David Llewellyn, PhD, said he anticipated finding a connection between insufficient vitamin D levels and dementia. However, Llewellyn claimed he didn’t expect to find a connection this strong.

While Llewellyn’s team discovered a link between vitamin D and neurological health, he was cautious about providing medical guidance solely based on the study’s results.

“Clinical trials are now needed to establish whether eating foods such as oily fish or taking vitamin D supplements can delay or even prevent the onset of Alzheimer’s disease and dementia. We need to be cautious at this early stage and our latest results do not demonstrate that low vitamin D levels cause dementia,” Llewellyn commented. “That said, our findings are very encouraging, and even if a small number of people could benefit, this would have enormous public health implications given the devastating and costly nature of dementia.”