Also, individuals who have undergone certain surgical procedures, including intestinal resection, bypass, or bariatric surgery, which may reduce Vitamin B12 absorption, are also eligible
8 Bruising is Rare But Can Happen Most of the time, the injection will cause no bruising
The surgery was straight forward, and the swelling was surprisingly light
Pawlak R, Lester SE, Babatunde T
1 2 "Nutrients: Vitamin B-12" (PDF)
These include: nausea and vomiting diarrhea constipation abdominal pain bloating, gas, or burping indigestion or heartburn injection site reactions, such as bruising, itching, or skin rash fatigue (low energy) hair loss dizziness mild allergic reaction To learn more about some of these side effects, see the Side effects explained section later in this article