Vitamin B12 is an essential nutrient with several important roles in the body. Getting enough helps prevent deficiencies that can cause serious health problems, and some research has looked at other potential benefits.
In this article, we explore what Vitamin B12 is, the potential benefits of maintaining adequate levels and supplementing, who may be at risk of deficiency, and precautions to take with supplements.
Short Summary
- Vitamin B12 is an important water-soluble vitamin found in animal products and fortified plant-based foods.
- Vitamin B12 supports red blood cell formation, DNA synthesis, nerve function, and healthy homocysteine levels.
- Individuals on vegan diets, those with pernicious anemia, small intestine issues, chronic alcohol use disorder, and those taking metformin may be at higher risk of Vitamin B12 deficiency.
What is Vitamin B12
Vitamin B12 is a water-soluble vitamin that is essential for brain function, red blood cells, and nerve tissue. Animal products such as meat, fish and eggs are natural sources of Vitamin B12. It is also added to certain plant-based foods, like fortified breakfast cereals. A deficiency can occur due to inadequate intake or an inability to absorb it from food. Common signs and symptoms of deficiency include headaches, fatigue, hyperpigmentation, discolored nails, hair changes, vitiligo, and angular stomatitis.
Older adults, those on vegan diets, and those with pernicious anemia are at increased risk for Vitamin B12 deficiency. Because Vitamin B12 is found in animal products, those on vegan diets may benefit from supplementing with it or choosing fortified foods. People with pernicious anemia cannot absorb B12 normally from food and need medical guidance on treatment. Vitamin B12 is also part of the B complex vitamins and plays an important role in energy production.
Understanding the sources, recommended intake, potential drug interactions, and tips for choosing supplements can help you make informed decisions about your Vitamin B12 intake.
Potential Benefits of Vitamin B12
Vitamin B12 is an essential water-soluble vitamin that plays a major role in the formation of red blood cells, DNA synthesis, and proper nerve function. Supplementation of B12 may raise levels for individuals who are unable to maintain them on their own due to medical conditions or restrictive diets. It may also reduce homocysteine levels and support brain health. Research on B12 and mood is mixed, so it should not be used in place of care for depression.
Inadequate B12 levels can lead to an accumulation of homocysteine in the bloodstream. Supplementation with B12, B6 and/or folic acid has been studied in 8 studies for its effects on homocysteine levels in people with mild cognitive impairment. A 2022 review of these studies showed an average reduction of 31.9%.
B12 supplementation, in combination with other nutrients involved in homocysteine regulation, such as folate, can lower homocysteine levels. Whether that translates into lower disease risk has not been established.
Who is at Risk of Vitamin B12 Deficiency
Vitamin B12 deficiency is a serious condition that can result in a variety of health issues, including anemia, fatigue, and neurological problems such as depression, confusion, and memory problems. It is important to identify those at risk, and to see a healthcare provider for testing and guidance if you suspect a deficiency.
Certain individuals may be more prone to Vitamin B12 deficiency than others. Individuals on vegan diets, those with pernicious anemia, those with small intestine issues such as Crohn's disease, gastritis, celiac disease, and inflammatory bowel disease (IBD), as well as those with chronic alcohol use disorder and those taking the diabetes medication metformin may be at higher risk. Those on strict vegetarian diets may be at risk due to the lack of animal products in their diets, which are the primary source of Vitamin B12. People with small intestine issues may be at risk due to interference with the body's absorption of Vitamin B12.
Recommended Dosage
The recommended daily intake of Vitamin B12 for adults is 2.4 mcg (micrograms). Most people who eat a varied diet get enough, and high-dose supplements are generally not necessary unless a healthcare provider recommends them.
High doses of Vitamin B12 are not generally considered dangerous, but only a small fraction of a large dose is absorbed. Consult with a physician before beginning any new supplement.
Pregnant and breastfeeding women have slightly higher recommended intakes, so ask your healthcare provider what is right for you.
Potential Drug Interactions
Metformin, proton pump inhibitors, histamine H2 receptor antagonists, and certain antibiotics have been known to potentially reduce Vitamin B12 levels and can decrease the absorption of B12 from foods. Vitamin B12 has been identified to have known drug interactions, including with anticonvulsants, chemotherapy drugs, and aminosalicylic acid. It is also possible that it may interfere with certain laboratory tests.
Patients taking medications like proton pump inhibitors, histamine H2 receptor antagonists, and metformin should consult their healthcare provider as these drugs have been linked to reduced B12 levels. Patients taking any medication should also be aware of potential interactions with Vitamin B12. The National Institutes of Health recommends patients talk to their healthcare provider about the possibility of Vitamin B12 deficiency, as well as their dietary options and the use of dietary supplements, to make sure their body's ability to absorb the Vitamin B12 they consume is not hindered by stomach acid.
Studies have found that Vitamin B12 deficiency is associated with an increased risk of autoimmune disease, cardiovascular disease, and nerve damage, and with elevated levels of the amino acid homocysteine. This is why it is important to understand how medications may affect your B12 levels.
Tips for Choosing Supplements
Dietary supplements are not approved by the FDA before they are sold, so choose products from reputable suppliers and be mindful when taking them.
When selecting a B12 supplement, consider your individual needs and preferences. Different forms of B12 supplements are absorbed differently by the body, and some people choose sublingual tablets. B12 injections are prescribed and given under a clinician's direction.
Taking a B-complex or multivitamin can provide the full range of B vitamins, not just B12. As with any supplement, make sure it is sourced from a reliable provider.
Health Benefits of Vitamin B12
Vitamin B12 plays an essential role in the body, aiding in the formation of red blood cells, DNA synthesis, and metabolism. Research has also explored links between B12 and age-related macular degeneration, cognitive decline, depression, osteoporosis, heart disease, and hair, skin, and nail health. These links are not fully established.
A 2009 study investigated Vitamin B12 supplementation and risk of macular degeneration in about 5,000 women aged 40 or older. In that study, combining Vitamin B12 with folic acid and Vitamin B6 was associated with a 34% lower risk of any form of the condition and a 41% lower risk of more severe types. This does not mean B12 treats macular degeneration, and anyone with eye concerns should see an eye doctor.
Megaloblastic anemia, which is characterized by fatigue and weakness due to a lack of healthy red blood cells, can be caused by B12 deficiency. If you have it, your healthcare provider will determine the cause and the right treatment. Elevated homocysteine levels, which are associated with an increased risk of age-related macular degeneration, may be lowered by B12 supplementation.
Adequate Vitamin B12 during pregnancy is important for the development of the fetus' brain and nervous system. Supplementing can also improve skin symptoms in individuals with B12 deficiency.
Although a Vitamin B12 supplement may improve hair, skin, and nail health in those who are deficient, it is unlikely to have a significant effect in those who are already well-nourished. Lower bone mineral density can be linked to an increased risk of osteoporosis, and B12 may play a role in bone health, but more research is needed.
Vitamin B12 for Energy
Energy is one of the most common reasons people look into vitamin B12. B12 is a member of the B-complex family and takes part in the chemical reactions inside cells that turn the energy stored in food into a form the body can actually use. It also supports red blood cell formation, which helps carry oxygen throughout the body.
How low B12 can affect your energy
When the body does not get or absorb enough B12, energy production can suffer. The result is often stubborn fatigue and lethargy, including feeling drained after a full night's sleep and finding routine tasks harder than usual. Weakness is another common sign, particularly when low B12 leads to anemia.
Supporting healthy energy levels
The most reliable way to keep B12-related energy steady is to make sure you get enough, either from B12-rich foods such as meat, fish, eggs and dairy, or from fortified foods and supplements if you eat a plant-based diet or have trouble absorbing it. Keep in mind that tiredness has many causes. If you feel persistently fatigued, talk to your doctor about checking your B12 levels rather than assuming a supplement is the answer.
B12's role reaches beyond energy, too. Adequate levels also help support mood and the nervous system.
Summary
Vitamin B12 is important for overall health. It is naturally found in animal products such as meat, eggs, and dairy, and some fortified plant-based foods contain it as well. It plays a key role in the production of red blood cells, which carry oxygen. It is also essential for proper nerve function and brain health, and it helps keep homocysteine levels in check, which is associated with heart health.
Research has explored links between B12 and conditions such as age-related macular degeneration, cognitive decline, depression, and osteoporosis, but these are not established benefits. Inadequate intake may be associated with an increased risk of autoimmune disease, cardiovascular problems, and nerve damage, so consider the manufacturer and quality when choosing supplements.
The recommended daily intake for adults is 2.4 mcg, and you should consult a physician before taking higher doses. Those at higher risk of deficiency, such as vegans, individuals with pernicious anemia, those with small intestine issues, chronic alcohol users, and metformin users, should be particularly careful to get enough.
Frequently Asked Questions
Is taking B12 everyday good for you?
Taking B12 daily is generally considered safe for most people, and since B12 is an essential nutrient, it is important to get enough from your diet or through supplementation. For those who are deficient, a supplement can help restore levels. B12 supplements are available in a variety of forms, including tablets. Speak with your doctor to determine if a supplement is necessary and what amount is right for you.
What symptoms does vitamin B12 help with?
Low B12 can cause symptoms such as fatigue and weakness, memory problems, anemia, mood changes, balance problems, and constipation. Correcting a deficiency may help these symptoms, but they have many possible causes, so see a healthcare provider before assuming B12 is the answer. B12 is essential for red blood cell formation, cell metabolism, nerve function and the production of DNA.
What happens if your vitamin B12 is low?
If your vitamin B12 is low, you may experience anemia, neurological symptoms such as numbness, and psychological issues like depression or confusion. It is important to get tested and follow your healthcare provider's guidance if you suspect a deficiency.
Who benefits most from vitamin B12?
People who are at higher risk of deficiency benefit most from making sure they get enough B12. This includes people on vegan diets, older adults, those with absorption problems, and those taking certain medications. Most people who eat animal products or fortified foods get enough from their diet.
Does vitamin B12 give you energy?
B12 helps the body convert stored energy into usable fuel, so it plays a direct part in energy production. People who are low in B12 often feel fatigued, and restoring healthy levels may help support their energy.
Can a vitamin B12 deficiency cause fatigue?
Yes. Fatigue and low energy are among the most common signs of a B12 deficiency, because cells need B12 to produce energy properly. If you are tired all the time, ask your doctor whether a B12 test makes sense.
How can I make sure I get enough vitamin B12 for energy?
Eat B12-rich foods such as meat, fish, eggs and dairy, or choose fortified foods and supplements if you follow a vegan diet. Talk to your healthcare provider if you have absorption issues or take medications that lower B12.
