Do B12 Shots Cause Anxiety?

There is a link between vitamin B12 and anxiety, although doctors are unsure of the details of this link. While anxiety is often correlated with a B12 deficiency, it is uncertain whether this is a direct result of the deficiency or a side-effect of the anemia that a B12 deficiency can cause. As such, it is difficult to assess B12's role in the development of anxiety.

B12 as a Treatment for Anxiety

• Because it is so often a symptom of a B12 deficiency, B12 injections are actually used to treat anxiety. Anxiety is a symptom of a B12 deficiency and an injection of B12 has proven effective in reducing anxiety, especially when the patient has a serious stomach condition that prevents the creation of certain stomach acids. The oral B12 supplements have not yet been proven to have an effect in lowering anxiety, however.

Common B12 Side Effects

• There are many common side effects of injections of B12 that can closely resemble feelings of discomfort experienced by people suffering from severe anxiety. Nausea and mild diarrhea, for example, are side effects that may be caused by an injection of B12, and are not considered unusual side effects.

Serious B12 Side Effects

• There are also very uncommon side effects of B12 injections that could resemble those felt during an anxiety attack. These are extremely serious, however, and medical help should be found as soon as possible if experienced. If rapid heartbeat, tightness in the chest, or dizziness are symptoms you experience, or you have difficulty swallowing or breathing after a B12 injection, quickly call a doctor and ask for advice.

Interactions With Other Medications

• A B12 injection may cause a conflict with other medications you are taking, and this may cause anxiety. You should never get a B12 injection without making sure that your doctor is aware of every medication you are currently taking and any conditions you have that the injection may affect. Things that your doctor should be aware of are vitamins and dietary supplements, which can often cause anxiety after a B12 injection. Conditions that your doctor should know about are kidney disease, liver disease, any infections, any other known deficiencies (especially iron and folic acid) and allergies you have to any medications or vitamins.

Seeking Help

• If you are suffering from anxiety and believe that this is a side-effect of a B12 injection, then talk to a doctor. Anxiety is not an expected reaction to a B12 injection, and it may signal some other problem. Until care is available, investigate possible causes such as drug interactions. Make sure you're not taking any vitamins your doctor didn't know about at the time of the injection, and make sure to avoid alcohol or drugs. When you can seek help, make sure you tell the doctor that you checked all of these things.