Vitamin B12 is essential for nerve function, red blood cell production, and DNA synthesis — and low levels can show up as fatigue, brain fog, balance issues, numbness or tingling, and mood changes often written off as normal stress or aging.
That’s broadly accurate. A more precise version would be: Vitamin B12 is essential for healthy nerve function, red blood cell formation, and DNA synthesis. A deficiency can cause fatigue, weakness, cognitive changes, numbness or tingling, balance problems, and mood changes. Because these symptoms can develop gradually and overlap with normal aging or other conditions, B12 …









