How to Get B12 as a Vegan and Raise Your Levels Quickly

How to get B12 as a vegan was one of the very first things I researched when I first decided to eat an exclusively vegan diet. 

Few plant foods naturally contain vitamin B12. Because of this, vitamin B12 deficiency used to be one of the most common issues for new vegetarians and vegans. So I knew this was one vitamin I had to keep a close eye on.

In the past few years, this problem has been greatly improved through food fortification and supplementation. Despite this, insufficient vitamin B12 still remains a problem for some vegetarians and vegans. 

So, is it possible for you to get enough B12 from plant foods alone? 

And if not, which supplements and how much of them should you take?

Read on to find out more. 

Pin it for later!

Table of contents

• What is vitamin B12?
• Where can we find vitamin B12
  • Which plant foods contain vitamin B12 naturally?
  • Which plant foods are fortified in vitamin B12? 
• What happens if I don’t get enough vitamin B12?
  • Symptoms of vitamin B12 deficiency
  • Can I have a vitamin B12 deficiency without any symptoms?
• How to test your vitamin B12 status
• How much vitamin B12 should I take as a vegan?
  • How to get enough vitamin B12 from vegan supplements?
  • Can I get B12 as a vegan without supplements?
  • Can I take too much vitamin B12?
• How can I raise my B12 levels quickly?
• How can I increase my vitamin B12 absorption as a vegan naturally?
• To sum it all up

What is vitamin B12?

Vitamin B12 – also known as cobalamin – is a vitamin that is essential for making red blood cells and DNA. It’s also required for your nerve cells to function normally. 

Sufficient intakes of vitamin B12 help you stay energized, and also help reduce the risk of birth defects, premature births, and miscarriages in pregnancy (1, 2).

Vitamin B12 also plays a crucial role in the health of your brain, heart, kidneys and bones (3).    

In sum: Vitamin B12 is a vitamin essential for your body to function normally. It plays a role in energy metabolism, bone health, as well as brain, nerve, heart, and kidney function. 

Where can we find vitamin B12

Vitamin B12 is naturally found in meat, fish, shellfish, dairy, and eggs. Basically, all foods that vegetarians and vegans either avoid or eat only in part. 

Vitamin B12 is actually made by bacteria. Animals accumulate vitamin B12 in their flesh because they consume unsanitized food and water. In addition, farmers often supplement their animal feeds’ with additional vitamin B12. 

Back in the day, humans likely consumed at least part of their vitamin B12 in the same way. By eating unwashed produce, or drinking water from streams that may have come in contact with these B12-producing bacteria. 

As modern humans, we tend to wash the soil off our foods before eating them. As such, the bacteria from the ground gets washed off. 

What’s more, some argue that our soil is no longer as nutrient-rich as it once was. Therefore, it may contain less vitamin B12-producing bacteria to begin with. .

Which plant foods contain vitamin B12 naturally?

Most plant foods contain only traces of vitamin B12 (4).

Shiitake mushrooms and fermented foods, like tempeh, natto, and sauerkraut can contain some vitamin B12. However, their B12 content is very variable, thus unreliable. For this reason, it’s best to not rely on these foods as your sole source of vitamin B12  (5, 6, 7, 8).

Spirulina and wakame are sometimes also touted as good plant sources of vitamin B12. However, they appear to contain large quantities of vitamin B12 analogues; a form of vitamin B12 that may not actually active in humans (5, 6).

On the other hand, recent studies have shown that purple laver (nori), Wolffia globosa (duckweed) and Taiwanese laver (hong-mao tai) may possibly increase vitamin B12 levels in humans. 

However, the current research suggests that the dose found to do so may still be insufficient to keep vitamin B12 levels optimal. Therefore, more research is needed on this topic before strong conclusions can be made (4, 5).

In the meantime, vitamin B12-fortified foods and supplements remain the most reliable source of vitamin B12 for vegetarians and vegans. 

Which plant foods are fortified in vitamin B12? 

Fortified foods can be a reliable way to get enough B12 as a vegan or vegetarian.

Foods often fortified with vitamin B12 include:

• Meat replacements
• Plant milks
• Breakfast cereals
• Nutritional yeast
• Marmite

Again, these foods are only considered reliable sources of vitamin B12 if they are fortified with this vitamin. For instance, unfortified nutritional yeast or marmite provide little to no vitamin B12. 

You can tell whether a food is fortified in vitamin B12 by looking at its ingredients label. Look for either vitamin B12 or cobalamin. 

Another tip worth noting is that vitamin B12 is light-sensitive. This means that it tends to degrade when in contact with light. For this reason, make sure to avoid vitamin B12-fortified foods that are sold or stored in clear containers or plastic bags (9).

 In sum: Shiitake mushrooms, fermented foods, and certain sea vegetables naturally contain some vitamin B12. However, amounts can vary, and are possibly too small to make a difference. Fortified foods and supplements are more reliable options. 

What happens if I don’t get enough vitamin B12?

Your body needs vitamin B12 to produce red blood cells. In turn, red blood cells help transport and distribute oxygen throughout your body (1).

Too little vitamin B12 can cause less oxygen to be delivered to your tissues, which can cause fatigue. This is known as anemia. Anemia can also be a result of getting too little iron or folate. 

Vitamin B12 also helps clear methylmalonic acid (MMA), in turn, protecting your nervous system. That’s why too little B12 can also cause confusion, memory loss, and numbing or tingling in your hands and feet (1).

Vitamin B12 also helps clear excess homocysteine (Hcy) from your body. Insufficient vitamin B12 intakes causes homocysteine to accumulate in the body. 

High homocysteine levels have been linked to an increased risk of heart disease, weaker bones, poor brain and kidney function, and premature death (3).

Symptoms of vitamin B12 deficiency

The most common symptoms of vitamin B12 deficiency include (2, 10):

• Pale skin
• Low energy
• Shortness of breath
• Palpitations
• Tingling or numbness in hands and/or feet 
• Lower sense of position of body parts
• Lower ability to feel vibrations
• Abnormal walking pattern
• Muscle weakness
• Loss of concentration
• Poor memory
• Confusion
• Depression
• Vision problems
• Insomnia
• Impotency
• Poor bowel or bladder control
• Constipation
• Flatulence 
• Sore tongue
• Appetite loss
• Loss of mental or physical drive

Can I have a vitamin B12 deficiency without any symptoms?

But what if you don’t have a reliable source of B12 in your vegan diet and still don’t have any of these symptoms?

Unfortunately, this doesn’t automatically mean that you’re off the hook. 

A vitamin B12 deficiency can develop slowly. Failing to have a reliable source of vitamin B12 in your diet will result in a vitamin B12 deficiency, even if you don’t (yet) feel its symptoms. This is known as a subclinical vitamin B12 deficiency.

In this case, you may not feel any overt symptoms, but you can still have elevated homocysteine or methylmalonic acid levels in your body. So it’s worth getting your levels checked, even if you feel perfectly fine (11).

This is especially important if you don’t have a reliable source of vitamin B12 in your diet, or tend to forget to take your supplements. 

Some people also have difficulty absorbing vitamin B12 as a result of bariatric surgery, pernicious anemia, obesity, Imerslund-Gräsbeck disease, Addison’s disease, or an intrinsic factor deficiency (12).

So it may be good to check your homocysteine and MMA levels at least once, even if you take vitamin B12 supplements, just to avoid any unpleasant surprises. 

In sum: Too little vitamin B12 in your diet can cause a range of health problems. A deficiency often takes some time to develop, and may not always show symptoms immediately. Testing your vitamin B12 status can help with early detection. 

How to test your vitamin B12 status

Serum vitamin B12 is the most common way to measure your vitamin B12 status (10).

However, this test alone has a wide range of what is considered “normal” and may fail to pick up all vitamin B12 deficiencies. 

Therefore, it’s worth asking your doctor to also check your blood homocysteine levels and blood or urine levels of methylmalonic acid (4).

Homocysteine levels can be elevated by other factors, including a folate or vitamin B6 deficiency. On the other hand, there is no other reason for methylmalonic acid to be high other than when vitamin B12 levels are too low. 

Because of this, MMA is currently seen as the most specific way to measure B12 status. 

Therefore, checking your MMA levels is a good way to know whether you are taking enough vitamin B12 or absorbing it properly. 

Elevated MMA levels despite taking vitamin B12 supplements consistently is an indication you’ll need to discuss an alternative plan of action with your physician or plant-based dietitian. 

In sum: Serum vitamin B12, homocysteine and methylmalonic acid levels are good indicators of your vitamin B12 status. It’s best to get all three, or at the very least, serum B12 and methylmalonic acid levels tested. 

How much vitamin B12 should I take as a vegan?

Vitamin B12 is most easily absorbed in small doses. The more frequently you take it, the smaller the dose you’ll need. On the other hand, the less frequently you wish to take it, the larger the dose you’ll need. 

Recommended daily intake of vitamin B12 per age category, based on the North-American recommendations are (1):

These recommendations apply to getting vitamin B12 from animal products or fortified foods. It also requires the daily recommendation to be spread over a minimum of three different eating moments throughout the day. 

While it’s possible to meet these recommendations through fortified foods alone, it requires more planning than simply taking a vitamin B12 supplement. 

How to get enough vitamin B12 from vegan supplements?

When it comes to supplements, recommendations depend on the frequency at which you wish to take your supplements. 

Typically, taking smaller doses more frequently is the most cost-effective way to meet your vitamin B12 needs. You can get enough B12 as a vegan by following these supplementation guidelines below.

For a deep dive into the rationale behind these recommendations, check out veganhealth.org. 

The recommendations above are based on cyanocobalamin supplements. Other forms of vitamin B12 exist, however, cyanocobalamin is the most thoroughly researched, affordable, and highly effective for most people (13).   

This is why cyanocobalamin is the form of B12 I recommend for most people. If you have a condition affecting your ability to absorb vitamin B12, a different form of B12 will likely be better suited for you.

For child-specific supplementation requirements of other nutrients, check out my Dietitian’s Guide to Vegan Supplements for Kids.

Can I get B12 as a vegan without supplements?

Can you get B12 as a vegan without supplements? Yes, you can.

However, this will require you carefully plan to meet your daily vitamin B12 requirements through three approximately equal doses of vitamin B12-fortified foods spread over three eating moments throughout the day. 

An easier alternative is to opt for a vitamin B12 supplement. This will keep you covered even if you accidently buy non-fortified meat replacements or plant-based milks.

Can I take too much vitamin B12?

Vitamin B12 is a water-soluble vitamin. This means that if you take more than you need, the excess will be excreted through your urine. 

So it’s virtually impossible to overdose on this vitamin (1).

In sum: How much vitamin B12 you should take depends on whether you’re aiming to meet your requirements through fortified foods, supplements, or a combination of both. The more frequently you take vitamin B12, the lower dosage you will require. 

How can I raise my B12 levels quickly?

If you haven’t been taking vitamin B12 supplements for anything longer than a few months, you may want to start by taking 2,000 micrograms (mcg) of vitamin B12 once a day for two weeks to replenish your stores. 

To increase absorption, try chewing your vitamin B12 supplements before swallowing. 

Also store your vitamin B12 supplements in a dark cool place, to avoid premature degradation. I store mine in the refrigerator. 

In the case of severe vitamin B12 deficiency, consider discussing with your physician whether vitamin B12 injections can be an appropriate option. 

Consistently including  vitamin B12-fortified foods to your diet a few times per day is yet another way to help increase and maintain adequate vitamin B12 levels. 

Keep in mind that it will be very difficult to rapidly increase your vitamin B12 levels through fortified foods alone. In the case of deficiency, a supplement or B12 injection are likely your best course of action. 

How can I increase my vitamin B12 absorption as a vegan naturally?

Some people recommend avoiding excess fiber, or trying not to combine  your vitamin B12 with tannins, alcohol, or high levels of zinc as means to boost absorption. 

However, there seems to be no evidence that any of these have any effect on your body’s ability to absorb vitamin B12 (10).

I also could not find any evidence of alcohol inhibiting vitamin B12 absorption. But I don’t know many people that would be taking their vitamin B12 supplement with a beer or glass of wine anyways!

According to vegan dietitian Jack Norris, you may want to chew vitamin B12 supplement rather than swallowing it whole, and try to avoid cooking all of your B12-rich foods. 

What’s more, a vitamin B12 supplement alone, or part as part of a vegan multivitamin both seem equally effective at maintaining proper vitamin B12 levels, as long as the dosage is adequate.

In sum: You can raise your vitamin B12 levels quickly by taking a super dose of vitamin B12 or vitamin B12 injections, before resuming with the normal recommended dose. Including B12-fortified foods several times a day can also help. 

To sum it all up 

Vitamin B12 is essential for your health. 

As a vegetarian or vegan, you need to make a concerted effort to get enough of this vitamin. You can do so either through fortified foods, supplements, or, in the best case, a combination of both. 

A vitamin B12 deficiency can take a while to develop, and symptoms aren’t always apparent immediately. Some people also have difficulty absorbing vitamin B12 properly, and may develop a deficiency even despite taking supplements regularly. 

To avoid any unpleasant surprises, consider testing your vitamin B12 status at least once, even if you take supplements. You can do so by requesting a serum vitamin B12, methylmalonic acid and homocysteine levels check.