Other Adverse Reactions
Apart from these three major adverse reactions, MedlinePlus reports that patients taking vitamin B-12 injections may suffer from other serious side effects such as muscle weakness, leg pain, headache and dizziness along with extreme thirst, frequent urination and fatigue. Some of these side effects may be potentially fatal and hence, it is important talk to a doctor immediately if the patient experiences any of these symptoms.
Allergic Reactions
Allergic reactions such as hives, swelling of face, lips, and neck and breathing difficulties can occur in some individuals taking vitamin B-12 injections. Drugs.com recommends immediate medical attention for such patients as some of these reaction may be potentially fatal.
Cardiovascular Symptoms
Intravenous administration of vitamin B-12 can affect the cardiovascular system in certain individuals and lead to symptoms such as chest pain, fast heartbeat, shortness of breath and increased blood flow in the extremities such as legs, arms and fingers. MayoClinic.com also states that individuals undergoing angioplasty and coronary stenting to open up a blocked artery may increase their chances of restenosis due to vitamin B-12 injections. Hence, vitamin B-12 shots should be avoided in such patients.
Gastric Disturbances
Many patients taking vitamin B-12 shots may suffer from gastrointestinal issues such as nausea, upset stomach and diarrhea. These symptoms are usually mild and go away within a few days. However, it is important to talk to a physician if the symptoms are severe or if they persist for a long time.
