Should You Get Vitamin B12 Injections? Here's Everything You Need to Know
If you’ve been feeling extra tired or out of sorts recently, it might be more than post-holiday exhaustion. You could actually be suffering from vitamin B12 deficiency, and it can have some pretty serious consequences. Fatigue, weakness, numbness and tingling in your hands and feet, constipation, anemia, problems with balance and walking, and even issues with your memory can arise are all potential outcomes of a vitamin B12 deficiency. In fact, it can even cause irreversible nerve damage if it’s left untreated for too long.
Don’t freak out, though — for as serious as it can be, it’s also pretty easy to treat.
Many people resort to B12 supplements to get the job done, but recently, B12 injections, which can be administered by a doctor or self-administered, are becoming a more and more popular alternative. Of course, the idea of getting your vitamins via needle is a little intimidating, so we called in the experts to help explain the details.
Why do I need B12, and how do I know if I need B12 injections?
“Vitamin B12 is an essential nutrient for human health,” says Elizabeth Ko, assistant clinical professor of medicine at UCLA’s David Geffen School of Medicine. “It plays a key role in the function of the brain and nervous system, and it’s crucial to red blood cell production in the bone marrow. [It} also aids in DNA synthesis and is involved in the metabolism of carbohydrates, fats and proteins.”
Because vitamin B12 plays so many roles in the body, you don’t want levels to fall too low or problems are likely to present.
“A blood test confirms whether someone is B12 deficient,” says Alison Moliterno, a hematologist and associate professor of medicine at the Johns Hopkins University School of Medicine.
She adds that our bodies can’t create B12, so we rely on getting it from dietary sources, most of which are animal products like meat, eggs, and milk. For this reason, vegans can become deficient, but people who suffer from digestive problems often experience B12 deficiency, too. This is because B12 is absorbed in the ilium, which is part of the small intestine. In order for absorption to happen, B12 must combine with a stomach protein called intrinsic factor. So if the stomach or other parts of the digestive system aren’t functioning properly, B12 may not be absorbed properly and deficiencies can occur.
Your doctor will likely recommend daily, weekly, or monthly B12 shots if a blood test indicates your levels fall below a certain threshold.
Can’t I just use supplements instead of getting injections?
“For those who have a mild or moderate deficiency, or for vegans, then oral B12 supplements generally suffice,” Ko says. “For those who have a severe deficiency, injections can quickly raise the level." In other words, for people whose B12 deficiencies arise from issues with absorption, injections are often the best option. In fact, they're sometimes the only way to get B12 levels back to normal.
“Injections are the preferred treatment for patients unable to absorb vitamin B12, such as patients with autoimmune related anemia or pernicious anemia, or history of gastrectomy, which means partial removal of the stomach, or a history of bariatric surgery,” says Shanna Levine, a primary care physician and instructor of medicine at the Mount Sinai Health System.
Can I really give myself B12 injections or do I need to see a doctor?
Whether you see a medical professional for your injections or handle them yourself at home will all depend on your physician’s recommendation, but many people end up taking on the task themselves after getting a prescription.
“Generally, most of my patients learn to do it themselves or have a family member who helps,” Moliterno says. Some physicians, like Dr. Ko, recommend getting the injections within a medical office.
If self-administering, Levine says you should be trained in your doctor’s office to learn proper injection techniques before making any attempts to start treatment at home. Besides learning to inject the B12, you’ll be taught to sterilize the area, dispose of needles properly, and never use the same needle more than once, Levine said.
Is there anything to worry about with B12 injections, like possible interactions with other medications?
For the most part, you don’t have anything to worry about when getting B12 shots. Ko says there aren’t any major risks to B12 injections other than the possibility of localized irritation at the injection site.
Yet despite minimal risks, “Patients should only use injections if indicated by their healthcare provider, as the benefits of the treatment should outweigh any risks,” Levine says. She adds that one possible side effect is something called hypokalemia, which is when potassium levels in the blood are low.
If I’m a good candidate for B12 injections, do I need to take them forever?
Overall, the duration of your treatment will depend on the reason for the deficiency. Most patients who have a medical condition that prevents proper B12 absorption will need to stick with the injections throughout life to keep their B12 levels in a healthy range. But some people can eventually transition from injections to oral supplements, Levine says.
“If the cause is not reversible, then treatment is lifelong,” Ko says.
If you think you might have a B12 deficiency — and particularly if you think you're a good candidate for injections — the best move is to talk to your doctor about your options.