Methylated B12 vs Cyanocobalamin Absorption Rates: Which Works Better?

Studies show that both forms of B12 absorb well in your body, with cyanocobalamin absorbing at about 49% and methylcobalamin at 44% for small doses. However, methylcobalamin stays in your body longer and may work better for people with certain health issues.

This article will help you understand how each form of B12 gets into your body and which one might be the best choice for you.

What Is B12 and Why Does Your Body Need It?

B12 is a vitamin your body needs to stay healthy. It helps make red blood cells, keeps your nerves working right, and gives you energy.

Your body cannot make B12 on its own. You must get it from food or supplements. Most people get B12 from meat, fish, eggs, and dairy products.

When you don’t get enough B12, you might feel tired all the time. You could also have trouble thinking clearly or feel tingling in your hands and feet.

The Two Main Forms of B12

There are two common types of B12 in supplements: methylcobalamin and cyanocobalamin.

Methylcobalamin: The Natural Form

Methylcobalamin is found in nature. Your body can use this form right away without changing it first.

This form of B12 is in foods like:

• Fish and seafood
• Meat and poultry
• Eggs
• Milk and cheese

Cyanocobalamin: The Man-Made Form

Cyanocobalamin is made in a lab. It is not found in foods naturally. Most vitamin pills and fortified foods use this type because it lasts longer on the shelf.

Your body must change cyanocobalamin into the active forms before it can use it.

How Your Body Absorbs B12

Getting B12 into your body is not simple. It takes several steps.

The Normal Way B12 Gets Absorbed

When you eat food with B12, here is what happens:

1. Your stomach makes acid that pulls B12 off the food
2. B12 attaches to special proteins
3. These proteins carry B12 to your small intestine
4. A special protein called intrinsic factor grabs the B12
5. The intrinsic factor takes B12 to the end of your small intestine
6. Your body absorbs the B12 through special gates

This process works best when your digestive system is healthy.

The Backup Way: Passive Diffusion

There is another way B12 can get into your body. It is called passive diffusion.

With this method, about 1% to 3% of B12 can slip through your intestine walls without any help. This happens when you take very large doses of B12.

If you take 1,000 mcg of B12, about 10 mcg will get absorbed this way. This is helpful for people who cannot absorb B12 the normal way.

Methylated B12 Absorption Rates

Studies have looked at how well methylcobalamin gets into your body.

How Much Gets Absorbed?

Research shows that when you take a small amount of methylcobalamin (about 1 mcg), your body absorbs around 44% of it.

This means if you take 10 mcg, about 4 to 5 mcg will get into your blood.

How Long It Stays in Your Body

One big benefit of methylcobalamin is that it stays in your body longer. Studies found that three times more cyanocobalamin leaves your body through urine compared to methylcobalamin.

This means your body holds onto methylcobalamin better. You may not need to take it as often.

Does Dose Size Matter?

The amount you take changes how much gets absorbed. When you take small amounts (2 to 5 mcg), your body absorbs more of it. When you take large amounts, less of it gets absorbed.

This is because your body has a limit to how much B12 it can take in at one time.

Cyanocobalamin Absorption Rates

Cyanocobalamin has been studied for many years.

How Much Gets Absorbed?

Studies show that cyanocobalamin absorbs slightly better than methylcobalamin for small doses. About 49% of a 1-mcg dose gets absorbed.

At low doses near what you need each day, absorption can be 40% to 50%.

What Happens with Bigger Doses?

When the dose gets bigger, less of it gets absorbed:

• At 5 mcg: about 20% gets absorbed
• At 25 mcg: only about 5% gets absorbed
• At 500 mcg: about 1% gets absorbed

This does not mean big doses are bad. Even 1% of 500 mcg is still 5 mcg getting into your body.

How Your Body Uses It

After cyanocobalamin gets absorbed, your body must change it. It removes the cyanide part (which is very small and safe) and turns it into methylcobalamin or adenosylcobalamin.

These are the forms your body can actually use.

Comparing the Two Forms Head to Head

So which one absorbs better? Let’s break it down.

Absorption Speed

Research from a 2020 study using special tracking showed that cyanocobalamin absorbs at about 46% for small doses that match daily needs.

Both forms work well. The difference in absorption is small for most people.

Staying Power

Methylcobalamin wins here. It stays in your body longer and at higher levels. This means you might need smaller doses or take it less often.

Which Works Better for Different People?

Cyanocobalamin may work better if you:

• Are vegan or vegetarian
• Want a cheaper option
• Need a stable supplement that lasts long

A study on vegans found that cyanocobalamin maintained better B12 levels in the blood than methylcobalamin.

Methylcobalamin may work better if you:

• Have the MTHFR gene change
• Have trouble absorbing vitamins
• Have nerve damage or pain
• Are older with low stomach acid

The MTHFR Gene and B12 Absorption

About half of all people have a change in their MTHFR gene. This gene helps your body use B12 and folate.

How MTHFR Affects B12

When you have MTHFR changes, your body has a harder time converting B12 into the active form. The more gene changes you have, the harder it is.

People with two MTHFR changes may lose up to 70% of their ability to process regular B12.

Why Methylcobalamin Helps

Methylcobalamin is already in the active form. Your body does not need to convert it. It can use it right away.

This makes methylcobalamin a better choice for people with MTHFR gene changes.

Testing for MTHFR

If you think you might have MTHFR changes, you can get tested. The test looks for two common changes: C677T and A1298C.

Knowing your MTHFR status helps you pick the right B12 supplement.

Factors That Change How B12 Gets Absorbed

Many things can change how well your body absorbs B12.

Age Matters

As you get older, your stomach makes less acid. Stomach acid helps pull B12 off food. About 10% to 30% of people over 50 cannot absorb B12 from food well.

Older adults often do better with B12 supplements because the B12 in pills is already free and ready to absorb.

Stomach Problems

If you have stomach issues, you might not absorb B12 well. Problems include:

• Low stomach acid
• Damage to the stomach lining
• Celiac disease
• Crohn’s disease
• Surgery that removed part of your stomach

Medicines That Block Absorption

Some medicines make it hard to absorb B12:

• Antacids and heartburn pills
• Diabetes medicine like metformin
• Some antibiotics

If you take these medicines, you may need extra B12 from supplements.

Your Diet

Vegetarians and vegans need to pay special attention. Plant foods do not have much B12. You must get it from:

• Fortified plant milks
• Fortified cereals
• Nutritional yeast
• B12 supplements

Learn more about why vegans need methylated B12.

How to Take B12 for Best Absorption

You can improve how well your body absorbs B12.

Best Time to Take It

Take B12 supplements in the morning on an empty stomach. This gives it the best chance to absorb.

Some people do better taking B12 with food to avoid stomach upset. Try both ways to see what works for you.

For more tips, see our guide on the best time to take methylated B12.

How Much to Take

The amount you need depends on several things:

Who You Are	Daily Amount Needed
Adults	2.4 mcg
Pregnant women	2.6 mcg
Nursing mothers	2.8 mcg
Adults over 50	25-100 mcg (from supplements)
People with MTHFR	500-1,500 mcg
Vegans	250-1,000 mcg

These are general guidelines. Your doctor can help you find the right dose for you.

Check our methylated B12 dosage guide for more details.

Different Ways to Take B12

Pills you swallow: These work well for most people. They are easy and cheap.

Under-the-tongue (sublingual): These tablets dissolve under your tongue. B12 goes straight into your blood. This works as well as shots for many people.

Shots: Doctors give these for serious B12 deficiency. They put B12 right into your blood, skipping your digestive system.

Nasal sprays and patches: These are newer options. They may help people who cannot take pills.

Taking It with Other Vitamins

B12 works better when taken with:

• Folate or methylfolate
• Vitamin B6
• Magnesium

These vitamins work together in your body. Taking them together may give better results.

Signs Your B12 Is Not Absorbing Well

Even if you take B12, it might not be getting into your body. Watch for these signs:

• Feeling very tired all the time
• Numbness or tingling in hands and feet
• Trouble walking or keeping balance
• Memory problems or brain fog
• Mood changes or feeling sad
• Pale skin
• Sore, red tongue

If you have these symptoms, talk to your doctor. A simple blood test can check your B12 levels.

Learn more about symptoms of B12 deficiency.

Testing Your B12 Levels

There are different ways to test B12.

Serum B12 Test

This is the most common test. It measures total B12 in your blood. Normal levels are usually 200 to 900 pg/mL.

But this test does not always show the whole picture. You can have normal levels and still have symptoms.

Holotranscobalamin Test

This test measures active B12 in your blood. It is more accurate than the regular B12 test. It shows how much B12 your body can actually use.

Methylmalonic Acid Test

When B12 is low, a substance called methylmalonic acid builds up. This test can catch B12 deficiency early, even before symptoms start.

Homocysteine Test

B12 helps break down homocysteine. When B12 is low, homocysteine goes up. High homocysteine can hurt your heart and blood vessels.

Safety and Side Effects

Both forms of B12 are very safe.

Is Too Much B12 Dangerous?

Your body gets rid of extra B12 through urine. There is no known toxic level for B12.

However, very high levels might mean something else is wrong. Always talk to your doctor if your levels are very high.

Learn about symptoms of high B12 levels.

Cyanocobalamin and Cyanide

Cyanocobalamin has a tiny amount of cyanide attached to it. This worries some people.

The amount is very, very small. Your body easily gets rid of it. Studies show it is safe for most people.

However, if you smoke or work around cyanide, you might want to choose methylcobalamin instead.

Rare Side Effects

Some people get:

• Skin rashes or acne
• Headaches
• Stomach upset
• Feeling anxious or jittery (especially with methylcobalamin)

These side effects are rare and usually mild.

Cost and Availability

Price can matter when you need to take B12 every day.

Which Costs More?

Cyanocobalamin is cheaper. It costs less to make and stays fresh longer.

Methylcobalamin costs more. It breaks down faster, so it needs special packaging.

Where to Buy Them

You can find both forms at:

• Drug stores
• Grocery stores
• Health food stores
• Online

Look for supplements that have been tested by third parties. This makes sure they have what the label says.

Research Studies on B12 Absorption

Scientists continue to study how B12 gets into our bodies.

Study on Vegans

One study looked at 42 vegans. Half took cyanocobalamin and half took methylcobalamin.

After several months, the cyanocobalamin group had better B12 levels in their blood. The average level was 150 pcg/L for cyanocobalamin and only 78.5 pcg/L for methylcobalamin.

The researchers said taking B12 more often helps keep levels steady.

Study on Absorption Rates

A study from 2020 used special tracking to measure B12 absorption. They found:

• At 2.3 mcg dose: 46% absorbed
• At 18.3 mcg dose: only 7.6% absorbed

This shows that smaller, more frequent doses work better than one big dose.

Studies on Nerve Health

Research shows both forms help with nerve problems. One review of seven studies found that both methylcobalamin and cyanocobalamin helped reduce nerve pain in people with diabetes.

Making the Right Choice for You

So which type should you choose?

Choose Cyanocobalamin If You:

• Want the most affordable option
• Are vegan or vegetarian without MTHFR issues
• Have normal absorption
• Want a stable supplement that lasts long

Choose Methylcobalamin If You:

• Have MTHFR gene changes
• Have nerve damage or pain
• Are older with low stomach acid
• Want a natural form that stays longer in your body
• Have trouble absorbing regular B12

You Might Need Both

Some people take both forms. Some supplements mix them together. This gives you the benefits of both.

Talk to your doctor or a nutritionist. They can help you pick the best type and dose for your needs.

Special Groups Who Need More B12

Some people need extra B12 or special forms.

Seniors

People over 50 should take B12 supplements. Their stomachs make less acid, making it hard to absorb B12 from food.

Methylcobalamin may work better because it does not need as much stomach acid to absorb.

Pregnant and Nursing Women

B12 is very important during pregnancy. It helps your baby’s brain and nerves grow.

Pregnant women need 2.6 mcg daily. Nursing mothers need 2.8 mcg daily. Both forms work well during pregnancy.

People with Digestive Problems

If you have stomach or intestine problems, you may not absorb B12 well. Options include:

• Sublingual methylcobalamin (dissolves under tongue)
• B12 shots
• Very high doses (1,000+ mcg) to use passive diffusion

People Taking Certain Medicines

Metformin (diabetes medicine) and antacids block B12 absorption. If you take these medicines long-term, you need extra B12.

Most doctors recommend 500 to 1,000 mcg daily for people on these medicines.

Beyond Absorption: How Each Form Works in Your Body

Getting B12 into your blood is just the first step. Your cells need to use it too.

Inside Your Cells

Once B12 gets into your blood, it travels to your cells. Inside the cells, it must be converted again.

Methylcobalamin is used right away for one job: turning homocysteine into methionine. This helps with:

• Making DNA
• Producing energy
• Brain health
• Mood balance

Your body also makes adenosylcobalamin from B12. This form works in your mitochondria (the energy makers in your cells).

Which Form Converts Better?

Both cyanocobalamin and methylcobalamin can be turned into any form your body needs.

Some people with gene changes have trouble making these conversions. For them, taking methylcobalamin gives their body one less step to do.

Benefits Beyond Basic Needs

Research shows B12 helps with:

• Energy levels
• Brain function and memory
• Mood and mental health
• Nerve health and pain
• Red blood cell formation

Both forms can provide these benefits when absorbed properly.

Common Myths About B12 Absorption

Let’s clear up some confusion.

Myth 1: “You Can’t Absorb B12 Without Intrinsic Factor”

Not true. The passive diffusion pathway lets about 1% to 3% of B12 absorb without intrinsic factor. Large doses can get enough B12 into your body this way.

Myth 2: “More B12 Is Always Better”

Not really. Your body can only absorb so much at once. Taking 1,000 mcg does not give you 10 times more B12 than taking 100 mcg.

Smaller doses throughout the day work better than one huge dose.

Myth 3: “Methylcobalamin Is Always Better”

It depends on your situation. For many people, cyanocobalamin works just fine and costs less. Methylcobalamin has benefits for specific groups.

Myth 4: “You Can Get Enough B12 from Plants”

Sorry, but no. Plants do not make B12. Some have tiny amounts from soil or bacteria, but not enough to meet your needs.

Vegans and vegetarians must take B12 supplements or eat fortified foods. Learn more at why vegans should take methylated B12.

The Future of B12 Supplements

Science keeps finding new ways to help B12 absorb better.

New Delivery Methods

Researchers are testing:

• Patches that deliver B12 through your skin
• Nasal sprays
• Special nanoparticles that carry B12 better
• Improved sublingual forms

Better Testing

New tests can show exactly how much B12 your cells are using, not just what’s in your blood.

Personalized B12

In the future, doctors might test your genes and recommend the perfect type and dose of B12 just for you.

Final Thoughts

Both methylated B12 and cyanocobalamin can give your body the B12 it needs. The differences in absorption rates are small for most people.

Cyanocobalamin absorbs at about 49% and costs less. It works well for many people, especially vegans who need consistent B12 levels.

Methylcobalamin absorbs at about 44% but stays in your body longer. It may work better if you have MTHFR gene changes, nerve problems, or trouble absorbing vitamins.

The best choice depends on your unique situation. Consider your:

• Age and health
• Diet and lifestyle
• Genes and absorption ability
• Budget and preferences

Talk to your doctor about testing your B12 levels. They can help you choose the right form and dose.

Remember, taking some form of B12 is much better than taking none at all. Both forms can help you feel more energetic, think more clearly, and stay healthy.

If you’re ready to try a high-quality methylated B12 supplement, explore our products. We use methylcobalamin combined with methylfolate for maximum benefit. Each bottle is doctor-approved and tested for purity.

Start feeling your best today with the right B12 for your body.