Some uncommon side effects that could occur are some weakness, nausea, bowel problems, dizziness, lethargy, weight loss, thirst, nervous irritability, itchy skin, frequent urination, high levels of calcium
The most common is slight redness, swelling, or tenderness at the injection site, which usually resolves quickly
If the patient is suspected to be sensitive to cobalt or other components of cobalamin, an intradermal test dose is recommended.[12][15] Several laboratory tests should be performed prior to treatment with cyanocobalamin, including serum vitamin B12, folate, iron, hematocrit, and reticulocyte count
B12 is vital for proper function and development of the brain, bone density, vision, and more
Fatigue is a common issue