Brain Fog or B12? The Hidden Nutrient Deficiency Mimicking Memory Loss

7. Impact on Mental Health and Cognitive Functions
B12 deficiency has a direct link to depression, anxiety, and dementia. This vitamin plays a role in producing brain chemicals that affect mood, such as serotonin and dopamine. Many cases of forgetfulness in the elderly, often misdiagnosed as Alzheimer's, are actually caused by severe deficiency of this vitamin.