What Is The Difference Between 'Active Vitamin B12' and 'Total Vitamin B12'?

What Is The Difference Between 'Active Vitamin B12' and 'Total Vitamin B12'? - welzo

If you eat a balanced diet, even one of the many plant-based diets, you should have adequate vitamin b12 levels.

But, sometimes, you might have come across terms such as "Total Vitamin B12" or "Active Vitamin B12".

This article will cover the differences between the two and the impact of Vitamin B12 on your health.

In short, vitamin b12 is either active or inactive.

The effectiveness of vitamin B12 depends on the proteins it is bonded to.

What is Vitamin B12?

Before we get into the details about the differences between active and total vitamin B12, we first need to understand what Vitamin B12 is.

B12 is a water-soluble mineral and essential nutrient that helps in red blood cell formation. Mostly, we get it from the food we eat, but, in some cases, it can also be derived from supplements.

The Chemical Structure of vitamin b12

Usually, we describe the chemical structure when talking about what a vitamin is. But, in the case of vitamin B12, it's too complex to put into words.

What we will say, however, is that it's got a complex structure that contains cobalt ions.

Why do we need vitamin B12

You might now be wondering why we even need vitamin B12.

The formation of red blood cells

To start with, as we've just mentioned, B12 helps to form red blood cells. If you don't keep red blood cells healthy, oxygen will not be able to travel around the body and power all our cells.

Therefore, it's vital to have normal levels of vitamin B12; otherwise, issues such as pernicious anaemia can arise.

DNA synthesis and creation

Another function of B12 is that it forms a small part of our DNA's genetic material. When cells replicate, they will take small amounts of the B12 we eat and use it to create the DNA of their clones.

The nervous system

Additionally, vitamin B12 aids in the creation and functioning of brain and nerve cells.

Without it, our brains cannot function properly.

The benefits of having enough vitamin b12

There are many benefits of having a B12-rich diet. Your body can create macronutrients from B12. Your energy levels will increase due to a higher red blood cell count.

And, you will be less stressed because of the vitamin's impact on your nervous system.

What is active Vitamin B12?

The first category of vitamin B12 that we'll cover is active. We know it might sound a bit strange to describe a vitamin as "active". But, your body can't use all forms of vitamin B12.

Active B12 binds to a type of protein called Holotranscobalamin. Only when it has attached to this protein can it be used by the body.

So as long as vitamin B12 is bound to a protein, stomach acid cannot damage it.

However, only when it's bound to Holotranscobalamin can it be transported by and synthesised with your body's other cells.

When you see something advertised as "high in vitamin B12", you should double-check that it's high in active vitamin B12.

What is inactive Vitamin B12?

There is another type of vitamin B12, and that is inactive B12.

As you may be able to deduce, your body can't use inactive vitamin B12- cells won't take it up—neither red blood cells nor any of your body's other cells.

Because it is saturated with chemicals from the protein it's bonded to; it cannot bond to the substances in any cells.

Inactive vitamin B12 is bound to a type of protein called Haptocorrin. Therefore, it is still protected from stomach acid.

What is total vitamin B12?

Now we've covered both active and inactive vitamin B12. But, what is "total vitamin b12"?- in short, it's just the total amount of both forms of vitamin b12.

So, when food is advertised as high in "total vitamin B12", you don't automatically know whether it contains an active form of the vitamin. The body can only use active vitamin B12. Vitamin B12 is not absorbed by the body and you could face a deficiency even if blood test results show a normal range of vitamin b12.

Also, the total vitamin b12 levels that may show in a blood test do not always measure active vitamin b12. You can still have a vitamin b12 deficiency, even if your blood tests show high vitamin b12 levels.

Listen to your doctor's advice if they are concerned about any medical condition related to your vitamin b12 levels.

Foods high in Vitamin B12

If your doctor has recommended you try to have more vitamin B12 in your diet, here are some foods you could include:

  • Clams. A common type of shellfish that you can buy at most fishmongers. Although for some people, it is an acquired taste.

  • Liver. Usually, from a cow. The liver helps with digestion.

    Various types of fish.

  • Trout

  • Salmon

  • Tuna

  • Beef and dairy products

  • Yoghurt

  • Milk

  • Eggs

But, this does not mean that people on plant-based diets never have enough vitamin B12. Here are some great sources of B12 if you do not wish to eat meat.

  • Plant milk

  • Fortified Breakfast cereals

  • Margarine

  • Yeast

  • Tofu

  • Fruit Juice

What if you have a low vitamin B12?

If you eat a poor diet with low vitamin b12, you are at higher risk of having the symptoms listed below.

If you notice any of the following symptoms, a lack of Vitamin B12 could be the cause, although that's a possible explanation, not a fact.

  • Yellow skin.

  • Poor vision.

  • Increased depression or fatigue.

  • Mouth ulcers.

  • Changes in how you walk.

Types of Vitamin B12

Earlier, we said that there are two types of vitamin B12, active and inactive. Although that is true, there are also several types of active vitamin B12.

You can find Methylcobalamin in animal-based foods. It is the most active form of vitamin B12 and helps maintain our liver, brain, and nervous system.

Adenosylcobalamin works in conjunction with Methylcobalamin. Adenosylcobalamin protects our cell's mitochondria, helping them to burn energy more efficiently.

Gut bacteria makes Hydroxocobalamin.

Our body converts it into Methylcobalamin and Adenosylcobalamin.

Cyanocobalamin is the only artificially created form of vitamin B12.

The body also converts it into Methylcobalamin and Adenosylcobalamin.

Because Cyanocobalamin has trace amounts of cyanide, be careful not to overdose.


Even if you have a normal range of vitamin b12, you are still at an increased risk of conditions such as pernicious anaemia, if most of the said vitamin b12 is inactive.

You can still have an active vitamin b12 deficiency, even if blood tests show normal vitamin b12 levels.

The main difference between the two types is that your body can only use active vitamin b12, and not inactive.

Next time a blood test shows normal levels of vitamin b12, you might want to double-check with a healthcare professional to see if the blood samples show the difference between active and total vitamin b12.

At Welzo we offer the B12 Blood Test, for more details click here.

For a full range of medications, visit our Welzo Online Pharmacy Page.

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