Study Links Low Vitamin D Levels to Higher Tau Protein in Brains of Adults

A study led by researchers at the University of Galway investigated the relationship between vitamin D levels and tau protein accumulation in the brains of adults.

The research tracked 793 participants who were free from dementia at the start, with an average age of 39 years when their blood vitamin D concentrations were first assessed. Approximately 16 years later, participants underwent PET brain imaging to evaluate levels of tau and amyloid beta proteins.

Researchers classified vitamin D readings above 30 nanograms per millilitre as high and those below 30 nanograms per millilitre as low.

Of the participants, 34 per cent fell into the low vitamin D category, while five per cent reported taking vitamin D supplements. The study appeared in Neurology Open Access on 1 April.

The participants in the study were predominantly white.

Vitamin D was measured only once rather than monitored over time. The study was observational in nature and cannot establish a direct causal relationship between vitamin D and reduced tau accumulation.

The research focused on adults without initial dementia to observe long-term brain protein changes.

research has suggested that Vitamin D may work by reducing inflammation, or by improving antioxidant defences and cell signalling, which may keep the tau protein from accumulating.

The study's implications for brain health emphasize the observational design and limitations.