Research carried out in the past has linked low vitamin D in adults over 70 with an increased risk of dementia. Photo: Getty

Research carried out in the past has linked low vitamin D in adults over 70 with an increased risk of dementia. Photo: Getty

People with higher levels of vitamin D in middle age may have lower levels of a protein in the brain, which is a sign of dementia, years later, according to Irish-led research.

Tau protein in the brain is one of Alzheimer’s biomarkers, the team from the University of Galway said.