Turn over a bottle of vitamins and you'll probably recognize many of the names on the label. Vitamin C. Vitamin D. Maybe zinc or biotin.

Then you get to vitamin B12 and see a much longer word in brackets: methylcobalamin or cyanocobalamin.

So, why are their different types of vitamin B12? And more importantly, does it matter which one is in your vitamin?

The short answer is that both forms can provide your body with vitamin B12, but they aren't exactly the same. One is a naturally occurring, active form of B12, while the other is a synthetic form that your body converts after you consume it.

Understanding that difference can make the vitamin aisle feel a little less confusing and help you understand why a brand might choose one form over another.

Vitamin B12 doesn't always get the attention of vitamins C and D, but your body relies on it for some very important jobs.

It helps your body make healthy red blood cells and DNA, and it plays an important role in the development and normal function of your central nervous system.

B12 is also frequently associated with energy, which can be a little misleading. Vitamin B12 is involved in processes your body uses to get energy from the food you eat, but that doesn't mean taking extra B12 works like drinking a cup of coffee. If you're already getting enough, more B12 isn't necessarily going to give you an instant energy boost.

Most naturally occurring B12 in our diets comes from animal foods such as fish, meat, poultry, eggs and dairy products. Plant foods generally don't naturally contain B12 unless they've been fortified, which is one reason people following vegan diets need to pay particular attention to where their B12 is coming from.

But when B12 is added to a multivitamin, there's another decision to make: which form of B12 should be used?

Methylcobalamin, sometimes shortened to methyl B12, is a naturally occurring and metabolically active form of vitamin B12. In other words, it's one of the forms of B12 your body actually uses in its normal biological processes.

You'll find methylcobalamin naturally in human physiology and in foods containing vitamin B12. That word active is important, but it's also easy to overinterpret.

It doesn't mean your body can only use methylcobalamin or that other forms of B12 don't work. It simply describes the form of the vitamin and what happens to it once it's in the body. And that's where cyanocobalamin is a little different.

Cyanocobalamin is a synthetic form of vitamin B12 and the most commonly used form of B12 in dietary supplements.

Unlike methylcobalamin, cyanocobalamin isn't itself one of the metabolically active forms of B12. After you consume it, your body converts it into active forms that it can use, including methylcobalamin and adenosylcobalamin.

That conversion isn't evidence that cyanocobalamin is bad for you. Our bodies convert nutrients and other compounds from one form to another all the time.

In fact, research using labelled cyanocobalamin has demonstrated that the body can absorb it and convert it into methylcobalamin.

So if cyanocobalamin works, why would someone choose methylcobalamin instead? That's where ingredient philosophy comes into the picture.

This is where vitamin marketing can get ahead of the science.

You'll sometimes see claims that methylcobalamin is dramatically better absorbed than cyanocobalamin simply because it's already an active form. Current evidence doesn't support making that blanket statement.

According to the National Institutes of Health, there is currently no evidence that the absorption rate of supplemental vitamin B12 differs based on its form. Its consumer guidance similarly notes that research hasn't established one supplemental form of B12 as universally better than the others.

So we're not going to tell you that cyanocobalamin doesn't work. It does.

But “does it work?” and “which ingredient would we prefer to use?” aren't necessarily the same question.

Methylcobalamin is naturally occurring and already one of the biologically active forms of B12. Cyanocobalamin is synthetic and requires conversion into active B12 forms after it's consumed.

For someone who prefers naturally occurring forms of nutrients when they're available, that's a meaningful distinction.

When we formulate Nutramin vitamins, the form of a nutrient matters to us too. Whenever possible, we look for naturally sourced ingredients that fit both the product we're creating and the people we're creating it for.

For vitamin B12, we chose methylcobalamin, a naturally occurring, metabolically active form of the vitamin, rather than simply defaulting to cyanocobalamin, the synthetic form most commonly used in vitamin products.

But that doesn't mean we believe there's one “right” form of every vitamin.

Take vitamin D, for example. Our Nutramin multivitamins contain vitamin D2, while Smart Sips uses vitamin D3. Both are forms of vitamin D, and each was chosen as part of the formulation of that particular product. If you've read our guide to [Vitamin D2 vs D3], you'll know there can be meaningful differences between different forms of the same nutrient, but that doesn't automatically make one appropriate choice for every formula.

The same balanced thinking applies to B12.

Research hasn't established that everyone needs methylcobalamin instead of cyanocobalamin. Our choice of methylcobalamin reflects something that's important to us when developing Nutramin: looking closely at the ingredients available to us and making deliberate choices rather than simply using something because it's the industry standard.

You may have come across some alarming information online about the name cyanocobalamin.

This is a good example of why context matters when you're researching ingredients.

Yes, the molecular structure of cyanocobalamin includes a cyanide group. But that fact is sometimes used online to make cyanocobalamin sound far more frightening than the evidence supports.

Vitamin B12 has a low potential for toxicity, and health authorities have not established an upper intake limit for B12 because of its low toxicity. Cyanocobalamin also continues to be widely used in fortified foods and vitamin products.

So we wouldn't tell you to avoid a vitamin because you've spotted cyanocobalamin on its label.

Our preference for methylcobalamin is about what we choose to put into Nutramin, not about frightening people away from another form.

It can matter, particularly if ingredient sourcing and naturally occurring forms are important to you. But it's also worth keeping the bigger picture in mind.

The form of B12 is only one part of a vitamin label. The amount you're getting, your diet, your ability to absorb B12 and whether you're getting enough in the first place can all matter too. Older adults and people following vegetarian or vegan diets are among the groups who may be at greater risk of inadequate B12 intake or status. Certain digestive conditions and medications can also interfere with B12 absorption.

If you're concerned that you may be deficient, particularly if you're experiencing symptoms or have a condition that affects nutrient absorption, that's a conversation worth having with your healthcare provider rather than simply choosing the bottle with the biggest B12 number on the label.

It's easy to turn over a vitamin bottle and focus on the familiar words and numbers.

Vitamin B12: check.

But that word beside it, methylcobalamin or cyanocobalamin, tells you something too. It tells you which form of the nutrient the company chose to use.

Both methylcobalamin and cyanocobalamin can provide vitamin B12. The science doesn't support telling everyone that they must choose one over the other.

At Nutramin, though, our choice is intentional.

We use methylcobalamin because it's a naturally occurring, active form of vitamin B12 and because choosing naturally sourced ingredients over synthetic alternatives whenever possible is part of how we approach formulation.

Sometimes understanding a vitamin label isn't about finding something to worry about. It's simply about knowing what you're looking at and being able to make a choice that feels right for you and your family.