IIf you spend any time on social media, you may have seen medical spa owners and employees describing vitamin B12 injections as a pick-me-up. When they’re exhausted or facing a busy week, they say, a quick shot gets them through. Some medical spas say many people feel a boost of energy within a day or two and recommend an injection every few weeks.
B12 is essential to your health, and people who don’t get enough of it can feel exhausted or worse. But most people already have plenty of vitamin B12, and for them, extra doses probably won’t help.
Here’s what you need to know about what B12 does, who’s missing it, and when to get tested.
What is vitamin B12?
Vitamin B12 is found naturally in animal foods like meat, fish, eggs and dairy, and it is added to some breakfast cereals and nutritional yeast. It helps your body make red blood cells and DNA, and keeps your nerves functioning properly. It also plays a role in transforming food into energy, hence its reputation as an energy booster.
When people don’t have enough B12, they can develop anemia, memory problems, depression and fatigue, says Andrea Dean, a hematologist at Loyola University Chicago Medical Center. If their levels are very low, they may also develop numbness and tingling in their hands and feet.
Why are some people deficient in B12?
Eating foods rich in vitamin B12 is not enough to ensure adequate levels. To absorb this vitamin, your stomach must produce enough acid, as well as a protein called intrinsic factor.
When people experience vitamin B12 deficiencies despite eating a balanced diet, it’s often because they have a disease that reduces stomach acid production (such as gastritis) or pernicious anemia, an autoimmune disease in which the stomach stops producing intrinsic factor.
About 4% of American adults have low levels of vitamin B12, and deficiency is most common among adults 60 and older. Other factors that increase risk include weight loss or stomach surgery, digestive problems like celiac or Crohn’s disease, and excessive alcohol consumption.
Taking the diabetes medication metformin or acid-reducing medications for a long time can also reduce vitamin B12 levels. Vegans and some vegetarians may also suffer from deficiencies unless they eat fortified foods or take a supplement.
Does taking B12 improve energy levels?
For people who experience fatigue or mental slowdown due to low levels of vitamin B12, treating this deficiency can restore their energy. But if your B12 levels are already adequate, consuming more won’t make you feel less exhausted or improve your athletic performance. Dean compares it to filling up a car: if the gas tank is already full, adding more gas won’t make the car go any faster.
Some people who feel more energetic after a B12 injection may experience a placebo effect. “We know some of this is just mental,” Dean says. For medical spa owners who endorse the injections, it’s also a financial issue: The injections cost at a typical American spa less than $1 each and are sold to consumers for between $25 and $75 each. The benefits add up when patients receive weekly injections.
There is not much risk for spas selling these shots. B12 is generally safe, even in high doses, because your body gets rid of what it doesn’t need, and Dean says she’s never seen anyone overdose on it. But if your B12 levels are normal, the injections are unlikely to be worth it.
When should I have my B12 level tested?
Fatigue has many possible causes, including poor sleep, low thyroid hormones, and low iron levels. “It’s not just about B12,” says Dean. So if you’re tired most of the time, it’s worth seeing a clinician who can investigate the cause.
A B12 level is a simple blood test that your GP can prescribe for you. In many US states and the UK, you can also order one yourself online from commercial laboratories. However, the results can be tricky to interpret on your own because you may be deficient even if your result appears normal. Most labs consider levels low if they are below 200 or 250 pg/mL, but Dean treats anyone with a level below 400 pg/mL. For people with borderline levels and symptoms, doctors may order two additional blood tests, called methylmalonic acid and homocysteine, to help confirm a deficiency.
If your level is low, your doctor also needs to determine why, because the cause affects how it is treated. Sometimes your medical history explains it, but if not, your doctor may test you for pernicious anemia.
How is B12 deficiency treated?
B12 can be taken in pill form or given by injection. The injections deliver the vitamin into a muscle or under the skin, bypassing the gut altogether.
This makes the injections the best choice for people with severe deficiency, nervous symptoms, or conditions like pernicious anemia that prevent them from absorbing B12. When someone has nervous symptoms, “we don’t play,” Dean says.
For many others, pills work just as well. High doses of oral B12 raise blood levels about as effectively as injections, and they cost less.
Gn Health
