B12 Shots Not Working? This Video Explains.

Posted by Dr. Robin Terranella

No time to read this? See video below.

Are those b12 shots not working like you expected?

There are several reasons for this but first we should look at what you were expecting would happen from your b12 shots. We will discuss this in a little more detail later but I think it is safe to assume most people take vitamin b12 shots expect an increase in energy and mood. These are good reason to consider b12 shots but if you are not getting any improvement you also want to pay attention to:

the type of b12 you are getting,
mow much and how often you get your injections,
certain lab values,
other vitamin deficiencies,
other diagnoses affecting the symptoms you expect the b12 to help with.

Here we will discuss these and other questions and considerations surrounding your b12 shots not working.

B12 Shots

In my clinical experience low or insufficient b12 is quite common. Mainly, because of issues surrounding absorption.

See other Video/ Blog on Vitamin B12 Absorption Issues for more.

Frank B12 deficiency is less common but I do see this fairly regularly as well. Here I want to discuss some of the things that come up when treating someone with b12 injections and it is not working.

So as mentioned the main thing we expect to occur from increasing b12 levels with b12 shots is energy and mood. It can also help with other things like neuropathy and other nerve disorders, memory, exercise intolerance, and shortness of breath. There are many other things that can improve from b12 shots but these are the main ones.

Reasons For B12 Shots Not Working

So if you are getting injections and not getting improvement why are the b12 shots not working?

1. The first and maybe obvious is that you are expecting too much from it. For instance, some people just take b12 because they are tired and expect it to improve their energy. This is fine, but if it is not working and you have no lab values to reference, it may be a good idea to look for another solution. This is especially true if you have done more than 3 injections and still find the b12 shots not working. Still keep in mind the points listed below as well because some conditions may require suffiecnt b12 levels for several months before seeing improvement.

Anther thing I sometimes see b12 shots being used for is weight loss. Now there are some reasons why b12 alone can help with metabolism but they are more subtle and likely only going to work if you have an actual deficiency. So if you are taking b12 shots alone for weight loss it is likely going to lead you to belief your b12 shots are not working. Really you should be looking for another reason you are having weight loss trouble.

2. Another big reason I find people saying their b12 shots not working is they are taking the wrong one. I usually ask this if someone says they are taking b12 shot and not noticing anything. The main one that we use and find helpful is methylcobalmin. The only one you can get from a drug store is called cyanocobalmin. This has a cyanide molecule attached to it so this has to be cleaved off and then the body adds a methyl or hydroxyl group to it. The process of adding the methyl group is not always efficient. Some people really need their b12 in the methylated form. So if you are taking one from a commercial pharmacy, look and see if it is cyanocobalamin. If it is, ask to get the methylcobalmin at a compounded pharmacy or through your doctor.

3. Another reason for b12 shots not working is the dose and frequency of the shots. If you are really low you may need to do an injection every week for for or five weeks before you notice changes.

For some people they actually have to have injections every week for genetic reasons. If you have issues with the tanscobalamin enzyme production you will need more b12. If you have issues with b12 recycling you will likely need more b12. As a result, if you only get an injection once per month you may perceive that your b12 shots are not working or they only last for a day or two.

4. A fourth reason for your b12 shots not working is that you have something else going on. B12 deficiency mimics many other things so if you are just getting b12 shots and have not been screened for other things, you should get screened. Also sometimes people have b12 deficiency and other things wrong too. If you correct the b12 deficiency and still feel poorly, you may need to dig deeper into the your health.

5. A fifth reason that your b12 shots are not working is that you have other vitamin or nutrient deficiencies in addition to the b12.

Because it has overlapping physiological roles in the body, a folate deficiency can have a very similar clinical picture to B12 deficiency. Such as the symptoms listed above and on laboratory evaluation. With b12 deficiency there can be an enlargement of red blood cells called macrocytiosis. This picture can also be caused by folate deficiency. Iron deficency and other nutrient deficiencies can also cause similar symptoms.

So I hope this information was useful in helping you think about and understanding why your b12 shots may not be working. Let me know in the comments below.

If you want a customized plan for b12 deficiency, click in the link below.