B12 Shots: Goal of Injectable Vitamin B

Angelica Bottaro
·7 min read

Medically reviewed by Melissa Nieves, LND

Vitamin B12 shots are a liquid form of the nutrient administered through an injection into a muscle. They contain a synthetic version of B12, otherwise known as cyanocobalamin. Typically, people with B12 deficiencies will be given injections. However, they can also be used to reduce the risk of developing certain health disorders, including neurological conditions and infertility.

This article discusses why a healthcare provider may prescribe B12 shots, their associated health benefits, and where you can get them.

<p>pawel.gaul / Getty Images</p>

pawel.gaul / Getty Images

Prescribed B12 Shots: When Would a Provider Recommend Them?

Vitamin B12 is a water-soluble (dissolves in water) vitamin that ensures the optimal health of blood and nerve cells. It also lends a hand in making DNA and can help prevent certain health conditions, such as megaloblastic anemia.

When people don’t get enough of the vitamin through diet, they are often recommended supplements. One such supplemental B12 known as a B12 shot is an injectable given intramuscularly (directly into the muscle).

The shots are typically reserved for people who do not get enough B12 in their diet or are deficient in the nutrient for various other reasons. Many factors can lead to a B12 deficiency, including:

When people fall into any of the categories mentioned above, they are more likely to develop a deficiency or are typically monitored for one so that they can be prescribed B12 shots if needed.



How to Tell If You Have a B12 Deficiency

Since a B12 deficiency comes on gradually, the symptoms tend to have a slow onset. If you notice any of the following symptoms, you may benefit from having your levels checked:

  • Numbness or tingling in the hands, legs, or feet

  • Issues with balance

  • Staggered walking

  • Anemia

  • Swelling and inflammation of the tongue

  • Memory loss

  • Difficulty reasoning or thinking

  • Weakness and fatigue



Related: The 8 Best B12 Supplements of 2023, According to a Dietitian

Optional B12 Supplement Shots

In some cases, people may believe they can benefit from B12. They may request B12 shots even if their healthcare provider doesn’t detect a deficiency and doesn't believe there's a need for them.

Possible health benefits of getting regular B12 shots include:

It’s important to note that B12 has no toxicity risk. Because of that, it can be taken in high amounts, even in people without a deficiency. However, that does not mean you should take more than you need.

Typically, a B12 deficiency leads to an increased risk of developing certain conditions, such as heart disease or having obesity, and the benefits lie in getting enough of the nutrient, not overdoing it.



B12 Shots Without a Deficiency

B12 is water-soluble, meaning that the body does not store it, and any excess amounts get flushed out of the body in the urine with other waste products. Because of that, if a person takes B12 shots but does not have a deficiency, it is more likely that the body will use what it needs and flush out the rest.



Related: The Best Sources of Vitamin B12 for Any Diet

Do B12 Injections Cause Side Effects?

While there is no upper limit when taking vitamin B12, the shots may pose some side effects in some people. Some adverse effects include:

  • Nausea or vomiting

  • Pain, swelling, or itchiness at the site of the injection

  • Diarrhea

  • Headaches

  • Dizziness

  • Hot flashes

In some cases, rare but more severe side effects can occur. Since a synthetic form of the vitamin is used, not everyone will tolerate it well. The severe possible side effects include:



When to Call 911 for a Serious Allergic Reaction

Some symptoms may develop after a B12 shot that indicates you need emergency services right away. Those signs include:

  • Swollen lips, mouth, tongue, or throat

  • Feeling as though you can’t breathe or rapid breathing

  • Difficulty swallowing

  • Blue, gray, or pale lips, skin, or tongue. In those with darker skin tones, this will be more visible on the palms and soles of the feet.

  • Feeling confused, drowsy or dizzy

  • Fainting and not being able to wake up

  • In children, becoming floppy or unresponsive

  • An itchy, blistering rash



Related: How Do You Know If You Have Allergies?

Where to Get B12 Shots

You can get B12 shots in one of two ways: through a healthcare provider or with at-home injections. While the safest way is through a healthcare provider, both can be done safely with the proper care and instructions.

Through a Provider

If you are prescribed B12 shots through a healthcare provider, they will likely develop a schedule for you to adhere to. You will visit their office at set times, and they will inject the vitamin there. They will then monitor you for any adverse effects.

You must visit the healthcare provider’s office every other day for two weeks to receive the shots. Once symptoms start improving, your B12 levels will be monitored accordingly to see how many shots you need to continue getting the right amount of the vitamin.

Self-Injection

Self-injections of B12 can also be done. However, if you have not yet had a B12 shot, you should first speak to a healthcare provider and have them do the first one so that you know how you react to it.

Once it’s deemed safe for you to do at home, you will be given a prescription for B12 shots you can take at home, or you can purchase them from a trusted health organization.

You and a healthcare provider will go over a schedule for you to adhere to so that you aren’t injecting too much or too little B12, and they will also provide you with instructions on how to do it.

The injections are given into a muscle, typically the thigh. To do so safely, you must follow these steps:

  • Prepare the needle and syringe as directed.

  • Clean the area on your thigh if you have not yet done so.

  • Inject the needle into the top outer layer of muscle in your thigh, in the middle area between the hip and knee, keeping the needle at a 90-degree angle.

  • Remove the needle and hold a cotton swab to stop any bleeding that may occur.



Getting the Right B12 Shots

The best B12 shots to get are the ones that your healthcare provider prescribes to you. Some health spas may also provide B12 shots, but you’ll want to ensure you get the best quality possible. Naturopaths and other licensed healthcare providers should be the only places you purchase B12 shots for at-home use.



Learn More: Dietary Supplements

How Many B12 Shots Will You Get?

The number of B12 shots a person needs will depend highly on their level of health and how deficient they are in the vitamin. Typically, someone with a deficiency will have to take one B12 shot every other day for two weeks until reexamining their levels.

From there, a healthcare provider will determine if more is needed and how often they should be given, based on a person’s response to the shots and their level of deficiency.

Summary

Vitamin B12 is an essential nutrient the body needs for various functions. While many people get enough through diet alone, some may be required to supplement their levels of vitamin B12 with injections. The injections, while relatively safe, can pose some side effects if they are not tolerated well by the person taking them.

Typically, a person with a severe deficiency will have to have B12 shots administered every other day for two weeks. This can be done at home or at a healthcare provider's office. You should avoid getting B12 shots online or from another retailer until you speak to a healthcare provider and check your levels. Getting the shots from a trusted healthcare professional is the best route if you need them.

Read the original article on Verywell Health.