Is it a good idea to take vitamin B12 every day? Here's what you need to know.

November 10, 2025 •

4 min read

According to the NIH, approximately 12.5% of adults aged 19 and older have a vitamin B12 insufficiency, suggesting many are not getting enough from their diet alone. Whether or not it is a good idea to take vitamin B12 every day depends heavily on your specific nutritional needs and lifestyle, from dietary choices to age.

Quick Summary

Daily vitamin B12 supplementation is beneficial for certain populations, such as older adults and vegans, who have higher risk of deficiency. While excess B12 is generally harmless, most people meet their needs through diet, and supplements are not necessary unless a deficiency or poor absorption is confirmed.

Key Points

Daily B12 is necessary for certain groups: Vegans, older adults, and those with absorption disorders are at high risk of deficiency and often require regular supplementation.
B12 is crucial for nerve and blood cell health: This vitamin is essential for DNA synthesis, red blood cell production, and maintaining a healthy nervous system.
Excess B12 is largely safe: As a water-soluble vitamin, excess amounts are excreted through urine, making it non-toxic even with higher intake.
Absorption rates differ: The body's absorption of supplemental B12 decreases significantly with higher intake, so larger quantities are often used to ensure adequate absorption.
Food sources are primarily animal-based: Natural B12 is abundant in meat, fish, eggs, and dairy, while fortified foods provide an alternative for plant-based diets.
Side effects are possible but rare: While generally safe, higher intake can cause mild side effects like headaches, skin issues, or digestive problems.
Consult a healthcare provider: Always speak with a doctor before ensuring regular B12 intake, especially if you take other medications or have underlying health conditions.
Higher intake isn't always better for healthy individuals: If you aren't deficient, taking more B12 than the recommended amount won't give you a noticeable energy boost.

The role of Vitamin B12 in the body

Vitamin B12, also known as cobalamin, is an essential water-soluble vitamin vital for numerous bodily functions. It plays a critical role in producing red blood cells, synthesizing DNA, and maintaining the health of your nerve cells. A deficiency can lead to a range of symptoms, including fatigue, nerve damage, and cognitive issues. Because your body stores B12 in the liver, it can take several years for a deficiency to develop, but once symptoms appear, they can be severe.

Who should consider daily Vitamin B12 supplementation?

While a balanced diet provides sufficient B12 for most people, certain populations are at a higher risk of deficiency and should consider daily supplementation.

Older adults

As we age, stomach acid production naturally decreases. Since stomach acid is crucial for separating vitamin B12 from the food protein it's attached to, this change can impair absorption. Health authorities suggest that adults over 50 years meet their B12 needs primarily through fortified foods or supplements.

Vegans and vegetarians

Vitamin B12 is found almost exclusively in animal products like meat, eggs, and dairy. Strict vegans, and sometimes vegetarians, are at a high risk of deficiency and are strongly advised to use supplements or eat fortified foods regularly. Experts recommend regular B12 intake for vegans.

Individuals with absorption issues

Certain medical conditions and treatments can interfere with vitamin B12 absorption.

Pernicious anemia: An autoimmune condition where the body attacks the intrinsic factor, a protein required for B12 absorption.
Gastric surgery: Procedures like gastric bypass can reduce the stomach's ability to produce intrinsic factor.
Digestive disorders: Conditions such as Crohn's disease and celiac disease can damage the part of the small intestine where B12 is absorbed.
Certain medications: Long-term use of acid-reducing drugs (like omeprazole) and the diabetes medication metformin can interfere with B12 absorption.

Is daily B12 safe? Understanding absorption

Vitamin B12 is water-soluble, meaning the body excretes any excess through urine, making it generally safe even with higher intake. For this reason, no tolerable upper intake level has been established. However, higher intake does not mean better absorption. The body's ability to absorb B12 from supplements is limited by intrinsic factor, so higher quantities rely on a less efficient process called passive diffusion. This is why the amount of B12 in supplements is often much higher than the amount that is ultimately absorbed.

Despite its low toxicity, some side effects are possible, including acne, headaches, or mild digestive upset. It is always best to consult a healthcare provider to determine the appropriate approach for your needs.

Choosing a B12 supplement

Supplements are available in various forms, with cyanocobalamin and methylcobalamin being the most common. Both forms are effective, though they differ slightly.

Supplement Comparison: Cyanocobalamin vs. Methylcobalamin


Feature	Cyanocobalamin	Methylcobalamin
Source	Synthetic	Naturally occurring
Stability	Highly stable	Less stable, more sensitive to light
Cost-Effectiveness	More cost-effective	Generally more expensive
Conversion	Converted by the body into active forms (methylcobalamin and adenosylcobalamin)	An active form, ready for immediate use
Metabolism	Releases a small amount of cyanide, harmless at standard levels	Does not contain cyanide
Common Use	Widespread in multivitamins and fortified foods	Often preferred in standalone B12 supplements

For most people, either form is acceptable. However, for those with kidney disease or who smoke, methylcobalamin may be preferable. For others, combining methylcobalamin and adenosylcobalamin is often recommended, as both are active forms that serve different functions in the body.

Natural sources vs. supplementation

For individuals with a reliable intake of animal products, getting enough B12 naturally is straightforward. However, for those with dietary restrictions or absorption issues, supplements become essential. The best approach for high-risk individuals is to rely on a combination of fortified foods and consistent B12 intake.

Food sources

Meat: Beef, poultry, and fish (e.g., salmon, tuna).
Dairy: Milk, cheese, and yogurt.
Eggs: A good source of B12.
Fortified foods: Many cereals, plant-based milks, and nutritional yeast are fortified with B12.

Conclusion

For those at risk of deficiency, ensuring adequate vitamin B12 intake is a good idea and a safe, effective strategy for maintaining health. This includes older adults, vegans, and people with certain medical conditions. For the average, healthy adult who consumes animal products, daily supplementation may not be necessary, as a balanced diet and the body's ample stores are usually sufficient. Before starting any new supplement, it is always best to consult with a healthcare provider to determine if regular B12 intake is right for you, especially if you take other medications or have underlying health concerns.

How to get more nutrition tips

For more information on dietary guidelines and nutritional needs, consider exploring resources from the U.S. Department of Agriculture or consulting a registered dietitian.

Dietary Guidelines for Americans

Potential risks and considerations

While vitamin B12 intake is largely safe, it's important to be aware of potential issues. High levels, while not toxic, may mask a folate deficiency, and certain rare genetic disorders require careful management. Consistent intake should always be managed under medical supervision. Regular blood tests can help monitor your levels and ensure your plan is appropriate.

The bottom line: Is daily B12 for you?

If you fall into a high-risk group—vegans, vegetarians, older adults, or those with malabsorption issues—then consistent vitamin B12 intake is a prudent and important health practice. For others, the focus should remain on a well-rounded diet rich in B12 sources. In either case, professional medical advice is the best way to determine your individual needs and the most effective approach for your health.

Frequently Asked Questions

Yes, taking vitamin B12 daily is generally considered safe, even with higher intake, because it is a water-soluble vitamin and the body excretes any excess through urine.

People who should consider daily supplementation include vegans and vegetarians, adults over 50, and individuals with medical conditions or on medications that impair B12 absorption, such as those with Crohn's disease or who take metformin.

The Recommended Dietary Allowance (RDA) for adults is 2.4 micrograms (mcg), but individuals with impaired absorption or dietary restrictions often require higher intake from supplements or fortified foods. Consultation with a healthcare provider can help determine the appropriate intake for your needs.

There is no established tolerable upper intake level for B12 due to its low toxicity. While excessive intake is uncommon, very high levels may rarely cause side effects like acne, headaches, or digestive upset.

Vitamin B12 is important for energy metabolism, but supplementing will not provide an energy boost if you are not deficient. Energy drinks and supplements marketed for energy are not proven to be effective for individuals with adequate B12 levels.

Methylcobalamin is a natural, active form of B12, while cyanocobalamin is a synthetic, stable form commonly used in supplements. The body converts cyanocobalamin into active forms, and both are considered effective.

Side effects from oral B12 supplements are rare. However, with higher intake, some people may experience mild diarrhea, headaches, or skin issues like acne or itching.

Common symptoms include fatigue, weakness, a sore tongue, headaches, memory issues, and nerve problems like tingling or numbness in the hands and feet.