Written and medically reviewed by Colleen Renee, MSN, APRN, FNP-C
Board-Certified Family Nurse Practitioner / June 3, 2026
This article explains what vitamin B12 does in the body, why low B12 levels can happen, and how deficiency may affect energy, brain function, mood, nerves, memory, and overall wellness. It covers common B12 deficiency symptoms, who m...