Vitamin B12 shots have been around for years, and they're often marketed as a miracle cure for everything from fatigue to depression to those stubborn extra pounds you can't shake. And while it's true that a B12 deficiency can contribute to those things, there is one problem, says Ashley Barrient, a clinical dietitian at the Loyola Center for Metabolic Surgery & Bariatric Care in Chicago: Most of us aren't deficient.
In the case of Vitamin B12, more is not necessarily better. It's is a water soluble vitamin, so once your body takes in a certain amount, the rest is discarded through urine. Adults only need 2.4 micrograms a day of B12, and most of us get that through foods like fish, beef, milk, eggs, and fortified breakfast cereals.
Strict vegetarians and vegans, or people with conditions that prevent them from absorbing nutrients from food, are the most likely people to be deficient. In these cases, says Barrient, B12 supplementation—either orally or with injections—may help improve symptoms like fatigue, mood changes, weakness, and memory loss.
“Some of our patients are found to be deficient in Vitamin B12, and through our physician prescribing appropriate vitamin supplementation, some individuals note an improvement in energy level," she says. "If a deficiency does not exist, supplementing Vitamin B12 will likely not have the same positive effect.”
B12 injections are available, for $15 to $50 a pop, at spas and wellness centers, but it's smart to talk to your physician before you spend money on them. If you really are deficient, only a medical test can prove it—and you'll want a medical professional to help you determine the underlying cause. Plus, says Barrient, the shots may be covered by insurance if your doctor can show that you can really benefit from them.
Bottom line: Unless you're truly deficient, a B12 injection probably won't give you lasting energy or help you lose weight. If you're still curious (or suspect you may really need them), get the shots in a doctor's office, rather than a non-medical setting.