Older Adults Need to Watch Their Vitamin B12 — Here’s Why

Vitamin B12 supports red-blood-cell production, DNA formation and the nervous system, but ageing can make adequate levels harder to maintain. Deficiency can also develop gradually, allowing neurological symptoms to emerge before the problem is recognised.

A 2025 UCSF-led study adds another concern: older adults at the lower end of the accepted “normal” range showed subtle signs of slower brain processing and greater white-matter injury. It does not prove that extra B12 prevents dementia.