✓ Evidence Based

7 Health Benefits of Vitamin B12, Backed by Science

Vitamin B12, also known as cobalamin, is an essential water-soluble vitamin that everyone needs for optimal functioning (1). It is one of the eight essential B vitamins.

Vitamin B12 is one of the most common deficiencies among all eight B vitamins because it is not abundant in all foods. Vitamin B12 is mainly present in animal-based foods and only a few plant-based foods are fortified with vitamin B12 (1), (2). That is one reason why vegans and vegetarians may have a hard time getting all the B12 they need in their daily diet (3).

This essential B vitamin is necessary for many functions throughout the body, ranging from the top of the head to all the nerves in the body, blood cells, and more. Malabsorption and digestive distress can cause B12 deficiency (4).

The methylation cycle requires vitamin B12, folate, and vitamin B6 to in the process of creating DNA and energy metabolism (5). DNA Methylation is a natural process that requires nutrients such as these and choline to get the job done right. B12 plays a critical role in folate metabolism, as well.

Summary: Vitamin B12, known as cobalamin, is a water-soluble vitamin. It is one of the 8 essential B vitamins. It is one of the most common vitamins people are deficient in, especially vegans and vegetarians because it is mostly found in animal-based foods. It is important for nerve function, blood cells, folate metabolism for energy, and much more.

Health Benefits of Vitamin B12

Check out the information below to see the many health benefits of vitamin B12. Plus, learn the best dietary sources if there are any potential risk factors.

1. It May Increase Energy

Are you feeling low in energy lately? It may be time to check your vitamin B12 level to determine if you are getting adequate amounts in your diet.

Vitamin B12 supplements have long been promoted as a means for boosting energy. This is because vitamin B12 is essential for the body’s metabolism to convert food into energy to keep you moving all day long.

However, there is no evidence to suggest that vitamin B12 supplements boost energy if your intake of B12 is sufficient (6). However, if your B12 levels are low, you may get an energy boost from increasing your intake of B12 or a supplement (7).

Summary: Vitamin B12 helps the body convert food into energy. If you are deficient in vitamin B12, you may get an energy boost from increasing your intake of vitamin B12.

2. It May Prevent Cardiovascular Disease

Cardiovascular disease affects millions of people across the globe, from a heart attack, heart disease, stroke, hypertension, and more (8). Heart disease is a common disease in the United States (9).

Homocysteine levels need to remain at optimal levels to maintain a healthy heart. Vitamin B12 plays a vital role in regulating homocysteine in the body (10), (11).

Along with folate and vitamin B6, vitamin B12 is necessary to keep homocysteine levels low. However, multiple studies of vitamin B12, folate and B6 supplementation have not been found to prevent heart attacks or strokes (12). More research is needed to understand this.

Many factors go into heart disease as well, including exercise, diet overall, and lifestyle habits. Those who have high lipoprotein (a) levels, obesity, diabetes, and more are risk factors for heart disease (13), (14).

Summary: Cardiovascular disease is a common medical issue, and vitamin B12 plays a vital role in heart health along with a healthy diet, exercise, and good lifestyle habits. Vitamin B12 helps to keep homocysteine levels low, which may help improve heart health.

3. It May Improve Sleep

Sleep is arguably one of the most critical factors for a healthy lifestyle (15). If you are not sleeping well and long enough, your body cannot take the necessary steps to repair and heal, no matter what you are eating. Sleep deprivation can lead to many downstream issues overtime for that reason.

While studies show that there is no direct link to vitamins and sleep quality, one study examined the effects of B12 on sleep quality (16). In this study, optimal levels of B12 can affect the circadian rhythm as well as the length of the sleep and wake cycle.

While B12 may also be a component to improve sleep, other studies have found different results. More research is needed to understand the link between sleep and vitamin B12 (17).

Summary: Vitamin B12 may be for promoting good sleep, but more research is needed.

4. It May Improve Cognitive Function

There is some evidence that vitamin B12 may be helpful for cognitive health, aiding in concentration, memory retention, and more.

There is some research that has found supplementation of B12 and folate can even slow brain atrophy in those with mild cognitive impairment (18). Often, low B12 levels can go hand in hand for those who suffer from neurocognitive issues as well, especially in the elderly (19). However, studies of supplementing with vitamin B12, folate and B6 have not been found to be effective in preventing or improving cognitive decline (20).

More research is needed to fully understand if vitamin B12 may improve cognitive function or prevent cognitive decline that occurs with aging in some people. A healthy brain is a complex topic. To improve cognitive health and maintain it for the long haul, you can be beneficial to eat balanced diet, exercise often, and continue learning new things.

Summary: Vitamin B12 may be helpful for improving cognitive function, concentration, and memory retention. It’s important to consume a healthy balanced diet with routine exercise for optimal brain health.

5. May Strengthen Hair and Nails

Even though B12 plays a significant role in blood cell formation, nerve health, and more, the benefits do not end inside the body. You can potentially see them on the outside as well.

If you suffer from brittle nails, hair loss, or even just hair growth issues, it may be helpful to get your B12 levels tested. These may be signs of a vitamin B12 deficiency (1).

In cases of vitamin B12 deficiency, increasing vitamin B12 intake can provide benefits for hair and nails (22). However, there is no evidence that supplementing with vitamin B12 can improve hair and nails in people who have adequate levels (23).

Summary: Vitamin B12 can help strengthen nails and hair if you are deficient. If you suffer from brittle nails or hair, hair loss, or hair and nail growth issues, it is recommended to test vitamin B12 levels. Supplementation and a change in the diet may be beneficial if levels are low.

6. It Can Improve Immune Function

A healthy immune system depends on many factors, but a well-balanced diet can help support healthy immunity. Along with vitamin B12, other essential B vitamins, vitamins C, D, A, magnesium, iron, zinc, are necessary to stay well (24).

Try to eat a healthy, balanced diet full of antioxidant-rich fruits and vegetables to stay healthy and disease-free for the long haul.

Summary: The immune system relies on vitamin B12, along with the other B vitamins, vitamins A, C, D, magnesium, iron, and zinc. Eat a balanced diet rich in vitamin B12, antioxidants, and other immune-boosting nutrients can help support a healthy immune system.

7. It Can Prevent Age-Related Macular Degeneration

Just like heart health, high homocysteine levels may be an impactful contributor to getting age-related macular degeneration (25).

Homocysteine levels cannot reach a certain level without harmful effects happening in the body. For some, those can show up as heart issues and vision troubles. Genetic factors can determine those odds, but remember that genetics is not the end all be all to your health (26).

There one study that found supplementing with vitamin B12, folate and B6 may reduce the risk of developing age-related macular degeneration (27). But more research is needed to confirm this.

Check out the food list below to see if you are getting enough vitamin B12 in your diet to boost energy, prevent vision trouble, improve your sleep habits, and more.

Summary: High homocysteine levels may impact age-related macular degeneration. Vitamin B12 helps to manage homocysteine levels in the body, and thus may help prevent vision troubles. Be sure to eat a diet rich in many nutrients including vitamins B12, C, E, zinc, lutein, and zeaxanthin for optimal eye health.

Foods that Contain Vitamin B12

Some foods contain high levels of vitamin B12, while others are on the lower end. If you eat a diet rich in animal-based foods with no gastrointestinal issues, you may be getting enough vitamin B12 (1). Older adults are also at risk of vitamin B12 deficiency (28).

For those who do not eat animal-based foods, fortified foods, and nutritional yeast are great staples. Luckily, you can add nutritional yeast to many dishes.

Summary: Vitamin B12 is prevalent in animal-based foods. For vegans and vegetarians, fortified foods and nutritional yeast are great substitutes for getting adequate vitamin B12 intake.

You can get your vitamin B12 from foods like the ones listed below (1):

  • Chicken
  • Fish-salmon, trout, tuna, haddock, clams
  • Beef and beef liver
  • Milk
  • Yogurt
  • Cheese
  • Nutritional yeast (a great option for vegans)
  • Ham
  • Eggs
  • Fortified cereal and some other foods

Anyone can try to add some nutritional yeast to their diet as a tasty alternative to cheese, as it has a subtle cheesy flavor. See where you can start adding more of these foods alongside your favorite vegetables and fruits.

Summary: Chicken, fish, beef and beef liver, milk, yogurt, cheese, nutritional yeast, ham, eggs, and fortified cereals are great options for getting adequate B12 intake. Nutritional yeast is perfect for vegans and vegetarians, it adds a “cheesy” flavor to foods. Sprinkle on vegetables, popcorn, or dips.

Are There Health Risks for Taking too Much Vitamin B12?

The short answer is no. There is no current evidence of side effects from taking too much vitamin B12 (1), (29). Keep in mind vitamin B12 is typically safe to take, as it is a water-soluble vitamin. That means it is easy to pass excess vitamin B12 through the urinary tract (30).

Certain medications can also impair you from absorbing enough vitamin B12. These include proton pump inhibitors, metformin, certain antibiotics, and more (1).

Not sure if you are getting enough vitamin B12? Be sure to speak with your doctor or healthcare professional if you experience any of the above symptoms or if you think it would make sense to get your levels tested. That way, you can see exactly how much you need to thrive. Your doctor can then assist you with the correct dosage.

Balance is the key to optimal health when it comes to vitamins, minerals, macronutrients, and micronutrients.

Summary: It is rare to get vitamin B12 toxicity. Since it is a water-soluble vitamin, it can pass easily through the body. Some medications can actually impair vitamin B12 absorption, including proton pump inhibitors, metformin, and some antibiotics. Speak with your doctor if you think you need to test your vitamin B12 levels.


Vitamin B12 is an essential water-soluble vitamin that helps protect red blood cells, neurons, skin cells, and more. It is necessary to get adequate vitamin B12 through foods, supplements, or both.

Taking or eating enough vitamin B12 can maintain many areas of your health, and monitoring your level can be helpful if you suspect a deficiency. Be sure to ask your doctor about vitamin B12 if you would like to know your levels.