In order for B12 to be absorbed from the gut, it requires a specific protein called intrinsic factor (IF)
Future research should focus on large-scale, well-controlled randomized trials with standardized dosing protocols, clearly defined deficiency thresholds, and long-term follow-up to strengthen the evidence base and guide clinical practice
Oral Facial Pain Headache 31 , e15e20 (2017)
Some people notice they feel energized after a B12 injection and assume the shot is driving weight loss
Common B12 deficiency symptoms include fatigue, anxiety, depression, poor memory, confusion, brain fog, tingling or numbness in the extremities, zings or zapping feelings in the extremities, anemia, shortness of breath, muscle weakness, irritability, tender calves, pale complexion and more
Individual experiences vary based on hydration, nutrition, sun exposure and general skincare habits