Vitamin B12 is an essential nutrient, one that your body doesn’t produce on its own. In other words, you need to rely on external sources to get your vitamin B12, meaning from your diet, adding supplements as needed and if you’re not getting enough B12 from food alone, and even B12 injections if warranted.
Like all B vitamins, B12 turns the food you eat into usable energy. But that’s not all that vitamin B12 does. This vitamin, chemically known as cobalamin, helps aid your body’s red blood cell production, keeps both your blood and nerve cells healthy, and plays a role in manufacturing your cells’ genetic material. And those are just the basic benefits of B12. Some research finds that vitamin B12 also plays a role in maternal and fetal health during pregnancy, may help reduce the risk of dementia, and lower homocysteine levels which, when elevated, have been associated with age-related macular degeneration. Read more about B vitamins here.
If you’re a meat eater, especially red meat, you may be able to sustain sufficient vitamin B levels without adding dietary supplements or even vitamin B12 injections. However, and this may surprise you, a bunch of people are deficient in vitamin B12, with government stats citing about 6% of U.S. adults under 60 years old and approximately 20% of those over 60 as vitamin B12-deficient. And that doesn’t even cover those who are insufficient in the vitamin.
What is a B12 Injection and Do You Need to Get Them?
There’s no mystery here. Just like the term says, B12 injections, sometimes just called B12 shots, are simply that: supplemental, synthetic vitamin B12 injected through a needle into your muscle or under your skin (not your vein) or to improve your vitamin B12 status and potentially offer a host of benefits. (As an aside, you can get intravenous (IV) administration of vitamin B12, sometimes called a vitamin B12 drip, and it’s similar to an injection in that it involves a needle and the same goals—but different ways of getting there.)
Although there is a lot of trendiness these days surrounding vitamin B12 injections, starting with celebrity endorsers, some of it is truly just hype. Why? Because some of the benefits—and there are benefits—for vitamin B12 injections may not kick in if you’re already sufficient or at optimal levels of B12. Which means that testing your B12 levels—through a doctor’s lab order or through an at-home test—should be among the first things to consider if you’re thinking about starting vitamin B12 injections.
On the other hand, here are some groups of people who may not only benefit from a B12 shot, but for whom that tactic may be highly recommended:
- People who have been tested for vitamin B12 status and are found to be deficient
- Older adults, a group known for having trouble absorbing B12 which could lead to less than desirable B12 status
- Vegans and vegetarians whose plant-based diet may put them at risk for vitamin B12 deficiency
- Patients with gastrointestinal issues that make vitamin B12 absorption difficult. These conditions include pernicious anemia, Crohn’s or celiac disease, bowel or pancreatic cancer.
- Those who engage in high alcohol consumption as alcohol in large amounts can lead to gastritis, a condition that impairs the body’s ability to properly absorb B12.
You can read more in this article.
Benefits of Vitamin B12 Injections
There are many reasons why you’d want to be sure that your vitamin B12 levels are in the sufficient (or optimal) range—and a vitamin B12 injection is one way to achieve that goal, especially if you need a boost because you’re not getting what you need from what you’re eating. In that case, though, a first step would more likely be to change your diet or to add dietary supplements. There are several options for getting B12 from (oral) supplements, including single B12 vitamins, B-complex vitamins and even a multivitamin.
For some people—specifically those with a vitamin B12 deficiency—a vitamin B12 injection may be medically necessary and something that your doctor will readily get on board with. For others not facing a deficiency, but still looking to improve your vitamin B12 levels, it may be as simple shifting your diet to include more food sources of vitamin B12 or by adding dietary supplements, both of which over time should help you reach your goal.
While you might be tempted to follow the trendy path to B12 injections, it’s not something you should jump into lightly, nor is it something your doctor will encourage unless they think it’s the only way to keep you vitamin B12-sufficient. FOMO is not a good enough reason to get B12 shots, in part because they are not necessarily risk-free (although they’re generally considered safe) and because some experts advise that unless you have a B12 deficiency, B12 injections will likely not give you the benefits that advocates of the shots tout.
Let’s look at some of those potential benefits.
For example, vitamin B12 injections are lauded for providing improved energy levels. B vitamins, and especially B12, are known as the energizer bunnies of the letter vitamins. And there is some truth to the notion that B12 will give you more energy. But it’s not as simple as it sounds. The energy boost comes from the role that vitamin B12 (as well as the other Bs) play in your metabolism which is this: the Bs turn food into fuel, thereby creating energy for your body to use.
Although your doctor should indicate the specific amount, vitamin B12 injections typically shoot 1,000 mcg directly into your body through a muscle or under the skin, making the “energy boost” feel more immediate than what you would get from a typical serving size of oral B12 supplements.
However, if your vitamin B12 levels are at least sufficient (and maybe even if they’re insufficient but not deficient), it’s unlikely that a B12 injection will have any additional impact on your energy levels. In fact, this article goes so far as to say that “injections are probably useless if you don’t have a deficiency.”
You might have also heard that vitamin B12 injections will help you lose weight. This post from the Mayo Clinic says “there’s no solid proof” that vitamin B12 injections will help you lose weight.
What about vitamin B12 injections for improving mood or cognitive function? While the research on vitamin B12 itself has shown some benefit in these areas, not all the research is conclusive. And whether injections would work any better than oral supplements is certainly up for debate.
In terms of boosting your red blood cell count, getting a vitamin B12 injection may be your best bet. But keep in mind that it’s a B12 deficiency which could cause the anemia, a condition where your body lacks healthy red blood cells. Do you see the pattern here?
Think of it like this. What research does tend to show is an association between low levels of vitamin B12 having harmful effects on your health. This article lays out some of the problems associated with a lack of B12. For instance, some research has linked low levels of vitamin B12 to a deterioration of brain function, weakened bones, age-related macular degeneration, and other health problems. So, in the cases of B12 deficiency, vitamin B12 injections may help improve your vitamin B12 status, thus potentially helping you avoid the consequences of low vitamin B12.
Risks Associated with Vitamin B12 Injections
Although serious side effects are rare for most people getting vitamin B12 injections, there are some things you should keep in mind (and discuss with your doctor) when considering whether vitamin B12 injections might be right for you.
Cyanocobalamin is the synthetic form of vitamin B12 that is used for B12 injections. Therefore, it makes sense for you to let your doctor or pharmacist or whoever is administering the injection know if you have any allergies, including to cyanocobalamin or cobalt, the latter being an essential component for vitamin B12 synthesis.
Don’t leave out things from your medical history, especially if you have kidney disease, low potassium blood levels, Leber’s disease (a specific eye disease), or other vitamin/mineral deficiencies (especially folic acid or iron). If you are pregnant or breastfeeding, vitamin B12 injections may not be for you.
Be sure to share your list of all prescription/nonprescription drugs and dietary supplements (including herbals) to avoid potential negative interactions before you get a B12 shot.
The more common side effects from a vitamin B12 injection include pain or redness at the injection site, itching or mild diarrhea. You may also experience swelling, even all over your body. If these symptoms don’t go away or get worse, let your doctor know right away.
Be aware that B12 injections may result in low potassium blood levels. And people with polycythemia vera, a rare blood disease, may experience serious symptoms that require immediate medical attention.
Although some people don’t experience any side effects from vitamin B12 injections, serious side effects include chest pain or shortness of breath, swelling in your feet or ankles, unusual fatigue, sudden vision changes, trouble speaking or weakness on one side of your body. Call 911 immediately.
Likewise, while an overdose from a vitamin B12 injection is very unlikely, call 911 if you experience trouble breathing or fainting.
How to Get a Prescription for Vitamin B12 Injections
By now, you’ve likely figured out that we’re proponents of involving your doctor in your decision about vitamin B12 injections. In addition to the fact that it’s important to have a network of smart and caring healthcare practitioners on your side, there’s also a more practical reason in this case. While there are some countries, the UK, Greece and Germany among them, where B12 shots are readily available without a prescription, here is the U.S., you do need a prescription for vitamin B12 injections.
And your doctor should have a medical reason for prescribing B12 injections, for example if you have a vitamin B12 deficiency. That deficiency can only be determined through a blood test (ordered by a doctor) or a urine test. At OmegaQuant, our at-home test measures methylmalonic acid in the urine, a specific indicator of low B12 status. When you get your written results report, you can share it with your doctor and if it’s determined you have a B12 deficiency, together you can decide your best course of action to correct that deficiency.