Vitamin B12, or cobalamin, is an essential nutrient that plays a key role in the development and function of brain and nerve cells and in the production of red blood cells and DNA.
Although most people can consume plenty of vitamin B12 through food, it’s also extremely popular as a dietary supplement. Around 24 percent of men and 29 percent of women report using a dietary supplement containing B12.
No matter how you get your B12, meeting your recommended daily intake may come with significant benefits. Here’s what research shows about the potential health advantages linked to this important nutrient.
1. Helps Boost Energy Levels
If you visit your doctor because you feel chronically fatigued, you’ll likely be asked about your diet. One thing your doctor may consider is whether a low intake of vitamin B12 may be contributing to your tiredness.
While getting enough vitamin B12 doesn’t directly lead to feeling more energized, it’s a player in the process. “The key word is ‘support,’ as B12 really helps with metabolizing the food we eat: carbohydrates, fats, and protein,” says Christiane Matey, RDN, founder of Mint Nutrition in Mooresville, North Carolina. According to Matey, vitamin B12 has a key role in helping our cells utilize glucose to make energy, and “without adequate amounts of this vitamin, people often feel fatigued,” she says.
Bottom line: While there isn’t enough evidence that people who have normal levels of vitamin B12 will experience a boost in energy from taking B12 supplements, research has shown that a deficiency of this important nutrient can make you feel more tired, and fatigue is a common symptom of a vitamin B12 deficiency. Therefore, getting adequate amounts of vitamin B12 from your diet and, if necessary, supplements, is something to discuss with your doctor.
2. Helps Prevent Anemia
Vitamin B12’s role in anemia prevention was foundational to its discovery. Researchers in the 1920s observed that consuming liver meat improved pernicious anemia, a type of anemia, or lack of red blood cells, that occurs when the body can’t absorb enough vitamin B12. (Red blood cells deliver oxygen throughout your body, which is crucial to keeping your body functioning properly.)
Eventually, researchers realized that this meat contains high amounts of B12, which helps red blood cells form properly in bone marrow.
“B12 is a cofactor in biochemical steps in the development of red blood cells, so red cell development and production are directly impaired when B12 is deficient,” says David Katz, MD, MPH, president of the True Health Initiative and founding director of the Prevention Research Center at Yale University in New Haven, Connecticut. “The red cells that do form are abnormally large, and their numbers are depleted.”
While pernicious anemia isn’t common, having certain conditions, such as Crohn’s disease or celiac disease, or following a vegetarian or vegan diet that doesn’t include enough vitamin B12 can increase your risk of developing this type of anemia. This B12-deficiency anemia can put you at risk for a range of health problems, from diarrhea or constipation to shortness of breath during exercise, confusion, memory loss, irritability, and numbness and tingling in your hands and feet.
Fortunately, a liver and onions dinner isn’t the only option for amping up your B12 intake to fight anemia. Supplements and other foods like clams, oysters, salmon, beef, and nutritional yeast can all elevate your levels.
3. Supports Nerve Function
Your nerves carry electrical signals between your brain and the rest of your body, creating sensation and maintaining important processes like breathing and digestion. Keeping them in good working order is critical for overall health.
According to Matey, getting enough B12 supports these neurological functions. “The protective coating around the nerves, known as the myelin sheath, relies on vitamin B12 to help it form,” she explains. “Vitamin B12 also helps maintain the spinal cord and nerves throughout the body.”
While consuming adequate B12 can be potentially beneficial for everyone, it may be particularly helpful for those with nerve problems or a traumatic brain injury (TBI), such as a concussion. “Those who suffer from traumatic brain injury may benefit from vitamin B12 treatments, as it helps regenerate nerve cells and boost nerve growth factor,” Matey says. More research is needed, but a review concluded that treating TBI with vitamin supplementation, particularly as soon as possible after the injury, may be helpful. According to the review, one animal study showed that administering B12 after TBI enhanced nerve repair and improved recovery.
4. Promotes Women’s Bone Health, Pregnancy, and Lactation
Though dietary intake recommendations for this key nutrient are the same for all adults, there are more benefits of vitamin B12 for women. “B12 is important during pregnancy and lactation, as these transfer the nutrient from mother to infant,” Dr. Katz explains. Because of this, and because vitamin B12 levels tend to drop during pregnancy, the daily value for pregnant and lactating women is higher than for the general population. Low levels of vitamin B12 have been linked to neural tube defects in infants, making getting sufficient levels especially critical during pregnancy.
Later in life, women may benefit from B12 for other reasons. Research shows that low B12 is associated with increased risk of osteoporosis, which is 4 times more common in women than in men.
5. Potentially Helps Maintain Mental and Cognitive Health
Vitamin B12 benefits aren’t all physical. Mental and cognitive health is also dependent on getting enough of this B vitamin. “B12 deficiency leads to reversible dementia, so the link is indelible,” says Katz.
One study identified low vitamin B12 levels as an “underestimated cause” of cognitive impairment and dementia, finding that replacement therapy could improve cognition outcomes in older people. As many as 84 percent of the 202 subjects in the study experienced improvement in cognitive symptoms after supplementing with B12 for three months.
Getting adequate B12 might also help improve mental health conditions like depression. A review found that while there’s no concrete evidence showing that vitamin B12 can reduce depression, lower levels in the body are associated with a higher risk of developing this condition.
6. Possibly Promotes Heart Health
Vitamin B12 is involved in the metabolism of the amino acid homocysteine. In the absence of enough B12, homocysteine levels can become elevated — an imbalance that may increase the risk of cardiovascular disease.
However, research hasn’t yet shown that supplementing with B12 can reduce heart disease risk. According to the Office of Dietary Supplements, studies have found that vitamin B12 and folic acid supplements lower homocysteine levels but not cardiovascular disease risk, and more research is needed to understand how B12 may impact heart health.
7. Contributes to Healthy Skin
For healthy skin, don’t skimp on vitamin B12-rich foods. Since this vitamin is involved in DNA synthesis, it promotes cellular turnover. “Cells won’t replicate well without sufficient B12,” Katz says. “So all organs depending on cell replication (including skin) will be impaired in their structure and function when B12 levels are low.” According to a review article, multiple skin conditions, such as vitiligo, acne, and atopic dermatitis, have links to too much or too little vitamin B12.
The Takeaway
From preventing anemia to helping reduce your risk of cognitive decline, vitamin B12 has a lot to offer for your health. While there is a lack of evidence showing that taking vitamin B12 supplements will definitely lead to health benefits such as increased energy or improved heart health, plenty of research shows that lack of this key nutrient is linked to a host of health problems.
To reap the benefits of B12, include foods like beef, eggs, fortified cereals, organ meats, salmon, and nutritional yeast in your diet, and talk to your doctor or a registered dietitian-nutritionist if you feel you may not be getting enough.
