Low vitamin D levels were linked with an increased risk of both dementia and stroke over the following 11 years. Based on this observational study, people with low vitamin D levels were found to have a 54% greater chance of developing dementia compared with people whose levels were normal.
A study published online April 22, 2022, by The American Journal of Clinical Nutrition suggests vitamin D deficiency may raise risk for dementia and stroke.
The study analyzed more than 294,000 people (most of them women over 60) living in the United Kingdom. Using blood tests on all participants and neuroimaging tools on about 34,000, researchers looked for associations between vitamin D levels and risks of dementia and stroke. A normal blood vitamin D level was defined as at least 50 nanomoles per liter (nmol/L); a deficiency was defined as less than 25 nmol/L.