Now that we know that vegetarians should take a B12 supplement, we are left with the question of how to choose from the multitude of supplements that we find in the market.

Often there is also conflicting information about whether one form of vitamin B12 is absorbed more than anotherwhether it is better to inject it or not, whether it should come with more vitamins or alone…

What you should look for when choosing a B12 supplement

We are going to do a short review of the key points when choosing a suitable B12 supplement. Remembering that we are looking for a supplement and a dose for healthy adults without deficit, who want to support themselves.

If you have a diagnosed vitamin B12 deficiency, or if you have been a vegetarian for a long time without having supplemented, consult a professional first. You may need to take higher doses for a while.

In this video we explain the symptoms of a lack of vitamin B12.

Which form of vitamin B12 is best

When buying vitamin B12, we can find it in different chemical forms. A maintenance B12 supplement for a healthy person should be in the form of cyanocobalamin for the following reasons:

• It’s the way more studied as a supplement and we know the dosage that should be recommended.
• It has no toxic dose.
• Is very stable to heat, light and pH, which is important so that a supplement that we store for a long time does not lose effectiveness.
• It is the most economical way, a factor that is basic in a supplement that should be taken long term or even for life.

Other forms of B12like methylcobalamin, should not be used without professional supervision, since we do not know the necessary doses well (we do know that they should be much higher than those of cyanocobalamin), nor are we completely clear about its metabolism or effectiveness in replenishing the liver reserve.

Methylcobalamin is used in some severe cases of deficiency with symptoms, or in smokers (combined with cyano), or in people with some liver or kidney diseasesIf this is your case, consult first with a specialized dietician-nutritionist who can advise you.

The recommended dose: daily or weekly?

We must ensure that the supplement has a sufficient amount of vitamin B12, since among the products that are for sale in our country many offer doses that do not meet needs of a vegetarian person.

The recommended dose depends on the frequency with which the vitamin is to be taken:

• The preferred dose is weekly. since it is the one with the greatest security of absorption because it does not depend on intrinsic factor (this is the name given to a protein secreted in the stomach that helps absorb vitamin B12 in the intestine). In that case we will choose a supplement that contains 2,000 mcg to take once a week. We can also take 1,000 mcg twice a week.
• If we are going to opt for daily supplementation, we will choose a supplement that contains between 25 and 100 mcg. Now, let’s remember that, in addition to being a more uncomfortable and more expensive dose, its absorption depends on more factors and is easier to suffer.

This last daily dose is much higher than the RDI (Recommended Daily Intake), which is 4 mcg per day according to the European Food Safety Authority, because B12 absorption is indirectly proportional to dose size (that is, the higher the dose, the lower the percentage of absorption). That is why the doses are not proportional when going from daily to weekly. And the RDI is intended to be consumed several times a day, not just once.

We could look at the RDI if we were to eat fortified foods several times a day, but it does not seem very practical or highly recommended, given that in our country fortified foods are not very suitable for daily consumption (they are mostly cereals and vegetable drinks, often sugary).

The method of administration: Oral or injectable B12?

As a form of administration The oral route will be preferred. Although it is still common for injected B12 to be recommended, today we know that pharmacological doses (above 1,000 mcg) have the same effectiveness as injection, even in gastrectomized patients, since, as we said, they directly diffuse the intestinal wall without the need for intrinsic factor. In very few cases it will be necessary to use injections.

By the way, the b12 ampoules which are sold as injectables can be drunk.

Although it is often heard, It is not necessary that B12 be accompanied by other B vitamins. Of course, it is interesting in some pathologies, but in the case of a healthy vegetarian person, in maintenance, the rest of the B vitamins are already provided by the diet and the weekly megadose does not need to be accompanied by anything else (if it has any, it is okay, but it is not necessary).