What is vitamin B12 good for and how often should you take it?

The global energy drinks market is booming. Valued at $86 billion in 2021, and it's forecasted to grow by another 8.4% this decade. Though companies within the industry first started marketing their products as energy boosters only, they are now promoting the inclusion of popular vitamins and minerals, giving some consumers the illusion that the drinks are healthy – despite often having as much sugar (or more sugar) than a bottle of Coca-Cola.

Among the most popular vitamins touted on the labels of such drinks is vitamin B12 – a nutrient known to help with energy, but usually not in the way the industry advertises.

What is vitamin B12?

Vitamin B12 is a water-soluble nutrient that helps keep one's blood and nerve cells healthy. It also aids in the production of DNA – the genetic material in all the body's cells. "Vitamin B12 can contribute to energy, mood, cognitive function and heart health," says Andrea Wong, PhD, a nutritional scientist at the Council for Responsible Nutrition. "There is also interest in the role of B12 in preventing cardiovascular disease, stroke and dementia," adds Kate Zeratsky, a registered dietitian nutritionist at Mayo Clinic in Rochester, MN.

Does vitamin B12 give you energy?

According to the National Institutes of Health (NIH) Office of Dietary Supplements, one of the reasons why vitamin B12 is associated with one's energy levels is because it "helps prevent megaloblastic anemia, a blood condition that makes people tired and weak." Beyond that association, the vitamin does help the body convert food molecules into energy as well.

That said, experts say that unless one already suffers from a vitamin B12 deficiency, there isn't strong evidence to support the notion that taking large amounts of vitamin B12 will increase one's energy levels.

What are the symptoms of B12 deficiency?

"Although vitamin B12 is just as essential as the other B vitamins, much smaller amounts of this vitamin are needed on a daily basis compared to the other vitamins," says Joel Mason, MD, a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. "Therefore, when a deficiency develops it tends to do so in a very gradual, insidious fashion."

Plenty of people are at risk of being deficient in vitamin B12: pregnant or breastfeeding mothers are commonly short on the nutrient. So are individuals who have undergone gastric surgeries. Vegetarians and vegans are too, because the main sources of vitamin B12 are in food products derived from animals. What's more, other individuals "have trouble absorbing vitamin B12 from food," says Wong. She notes that the "deficiency is especially common in older adults, primarily due to such problems with absorption."

People that are deficient in vitamin B12 can experience nerve problems such as when one's hands or feet become numb or tingly. "Deficiency can also lead to lethargy, diminished cognitive abilities, some types of dementia, emotional disorders and a loss of balance," warns Mason. Adds Zeratsky: "B12 deficiency can also result in megaloblastic anemia," – the aforementioned condition that causes feelings of exhaustion.

Can you take too much vitamin B12?

Though vitamin B12 can be found naturally in a wide variety of animal products, including meat and fatty fish, supplementation of the nutrient "may be recommended for some adults in the form of a supplement or as part of a multivitamin," says Zeratsky.

And while everyone from newborns to the elderly need vitamin B12, the amount varies with age. It's recommended for children 1-13 years old to get between .9 and 1.8 micrograms of the nutrient each day, whereas teens 14 and older and all adults should get 2.4 micrograms of it daily. Slightly higher levels are recommended for pregnant or breastfeeding women.

"Unlike some of the other vitamins," advises Mason, "vitamin B12 is felt to be exceedingly safe since there are no known toxic effects when administered in supplemental quantities."

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This article originally appeared on USA TODAY: What is vitamin B12 good for? Energy, health benefits explained