Top & Best Vitamin B12 Review 2021 – How to Select Ultimate Buyer’s Guide

Vitamin B12: How to choose the best one for you in 2021

Today we are going to talk about an essential vitamin for your health: vitamin B12.

Fundamental to maintaining the healthy functioning of the body, vitamin B12 is not produced by the body and therefore needs to come from dietary sources or supplements.

In the midst of so many options, we will show in this article what you should take into account before purchasing Vitamin B12 to meet your expectations and needs.

First, the most important

  • Part of the B complex, vitamin B12 is essential for the health of the blood and nervous system.
  • Deficiency of this vitamin in the body leads to anemia, tiredness, depression, among other problems.
  • We will show you what are the characteristics that differentiate the types of Vitamin B12 and how to choose the ideal formula.

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Buying Guide

It may seem simple to choose the ideal vitamin B12. But it is necessary to take into account the real need, the correct dosage, among other factors so that there is the expected result.

Therefore, we have created this Buying Guide with all the information you will need to make the best decision when purchasing your vitamin B12 safely.


What is vitamin B12?

Vitamin B12 is one of the nutrients that help maintain your body’s health. But, as it is not produced by the organism, it must be acquired from external sources.


As it is not produced by the organism, it must be acquired from external sources.

Part of a group of eight vitamins, called the B complex, vitamin B12 is also known as cobalamin or cyanocobalamin.

But the fact is that there are other types of this nutrient, as we will see later, in Purchase Criteria .

In addition to acting in the formation of red blood cells and in the maintenance of the nervous system, B12 is essential for other nutrients to act correctly in the body.

In practice, adequate consumption of the vitamin helps to prevent heart disease and nervous system changes, in addition to participating in metabolic processes, ensuring energy and emotional stability.


Since vitamin B12 is a micronutrient, the amounts that the body needs are considerably small.

Still, it can become deficient in the body. And, therefore, it can cause diseases, such as anemia, for example.

The good news is that, in general, it is not difficult to find products source of vitamin B12, either through food or supplements.

That is, in case of deficiency, you can reinforce the meal through the most appropriate consumption of B12 or, if necessary, supplement it with vitamins.

What is vitamin B12 for?

As we have seen, B12 is essential for the proper functioning of cells, especially those in the nervous system, bone marrow and intestine.

But its reach is even greater. Among the main actions of vitamin B12 in the body are:

    • Formation of blood cells: Red blood cells (erythrocytes) are responsible for transporting oxygen. Any change in its structure can therefore compromise the oxygenation of body tissues. Vitamin B12 acts on the correct division of blood cells, preventing them from becoming too big and fragile.
    • DNA repair: B12 indirectly participates in DNA structuring, as it acts as a coenzyme. In pregnant women, for example, vitamin B12 is necessary for the correct production of nucleic acid, reducing the risks of future problems.
    • Vitamin absorption: B12 helps in better absorption of other vitamins. For example, without vitamin B12, the body begins to show folic acid deficiency, which is also important for various body functions.



  • Improves conditioning: For you to be able to perform your activities, from simple to more complex, it is necessary that the organism has energy. If B12 is being ingested properly, muscle cells and tissues will receive the necessary amount of oxygen, preventing exaggerated tiredness.
  • Metabolizes nutrients: Vitamin B12 also acts on the metabolism of nutrients such as carbohydrates, proteins and fats. For example, if you want to lose weight, cobalamin helps to give you more energy, allowing you to do more physical activities and, therefore, burn more calories.
  • Helps the circulatory system: As B12 helps to reduce cholesterol levels, the entire circulatory system benefits. This results in a reduced risk of hypertension and heart problems.


  • Raises good cholesterol (HDL): B vitamins can promote HDL production in the liver and small intestine, decreasing the chances of a heart attack or stroke.
  • Healthier nervous system: Studies have shown that vitamin B12 protects neurons and can reduce neuronal degeneration.

How is vitamin B12 synthesized?

Although the dietary sources of vitamin B12 are of animal origin, the nutrient is actually synthesized by bacteria.

Therefore, foods of plant origin do not have vitamin B12. The fact is that animals have these bacteria in the intestinal flora or obtain them when they eat “contaminated” foods, such as grass, for example.

Thus, the vitamin is processed by the animals’ intestines and deposited in the tissues. When we consume, for example, the meat of the animal, we end up ingesting the nutrient.

Vitamin B12 is synthesized by bacteria that “contaminate” foods of animal origin.

On the other hand, plants, vegetables and fruits will only present B12 if they are contaminated by bacteria. But, unlike animals, vegetables do not produce B12.

We also have the bacteria responsible for producing B12. However, the amount is very small and the absorption of the nutrient is not sufficient. Hence the need for supplementation.

What foods are rich in vitamin B12?

As we have seen, the main source of Vitamin B12 is in foods of animal origin.

According to experts, the recommendation for vitamin B12 intake in healthy adults ranges from 2.5mcg to 3mcg per day.

Therefore, as we will see below, it is possible to exceed this amount of nutrient absorbed in the body with the consumption of, for example, 100g of beef liver steak.

To give you an idea, we have put together a list of some of the foods with good concentrations of B12 below:


In addition to these foods, we can also mention enriched rice milk, which contains about 1mcg of vitamin B12 every 200mL; and skimmed milk, which has 0.75mcg every 200ml.

The fact is that there is a consensus among experts that milk, eggs and derived products have a better absorption of the nutrient in relation to other foods rich in B12.

However, we are not always able to ingest the total amount of B12 present in food. That’s because B12 is sensitive to heat.

Thus, if you consume these products made at high temperatures, such as roasts or fried foods, for example, the nutritional quantities will be greatly reduced.

What is the recommended intake of vitamin B12?

The body is able to store between 3mg and 5mg of vitamin B12. However, about 50% of what is consumed is not used by humans.

In general, at each meal, our body can only absorb up to 1.5mcg of B12. Therefore, to ensure the necessary B12 rate, you must receive a much larger amount of the vitamin.

Thus, if food does not meet the ideal dosages, nutrition should be supplemented with the use of vitamin B12 supplements. In general, it is recommended to supplement 10mcg per day or 2,000mcg per week.

But, in cases of severe disability, these numbers can be much higher. For healthy people the suggested values ​​of vitamin B12 intake vary, in general, according to age, as you can see below:

    • 0 to 6 months: 0.4mcg / day;
    • 6 to 12 months: 0.5mcg / day;
    • 1 to 3 years: 0.9mcg / day;
    • 4 to 8 years: 1.2mcg / day;
    • 9 to 13 years: 1.8mcg / day;
    • Above 14 years old: 2.4mcg / day;
    • Pregnant women: 2.6mcg / day;
    • Lactating: 2.8mcg / day.


It is worth remembering that these values ​​may be even higher in the case of people with difficulties ingesting or illnesses.

For this reason, it is essential that you consult a specialist before starting vitamin B12 supplementation. After all, as we will see later in this article, the excess of this nutrient in the body can also be harmful.

How to know the level of vitamin B12 in your body?

To find out how well the vitamin B12 is doing in your body you need to have a blood test.

The reference value considered normal for B12 may vary between laboratories, but in general it is between 300pg / mL and 900pg / mL. Therefore, the values ​​should be evaluated together with your doctor.

Thus, when performing blood tests, you should keep in mind the average reference values ​​that are generally applied by laboratories. Are they:

    • Severe deficiency: below 150 pg / mL
    • Deficiency: between 150pg / mL and 200pg / mL
    • Possibility of deficiency: 200pg / mL and 300 pg / mL
    • Normal levels: between 300pg / mL and 900pg / mL
    • Hypervitaminosis: above 1000pg / mL


What can cause a lack of vitamin B12?

B12 deficiency can occur, among other reasons, when there is difficulty in absorbing the vitamin or when food is not able to meet the needs.

As a result, the concentration of vitamin B12 in the body begins to be reduced. In this situation, the liver releases the nutrient that is stored to try to replace the substance and allow the body’s functions to remain unaffected.

However, if B12 is not replaced, this stock will also run out. And then, the problems start to occur, even though the manifestation of the lack of B12 varies from person to person.


The fact is that cobalamin deficiency is little associated with eating habits. The following are the factors that most trigger the reduction of vitamin B12 in the body:

  • Nutrient absorption problems: when there are gastrointestinal changes and / or inflammation of the stomach, intestine and pancreas.
  • Acquired immunodeficiency syndrome (AIDS): B12 is present in low levels in most of the carriers due to the possible failure in the absorption of the nutrient in the intestine.
  • Surgical procedures in the intestine and gastric surgeries.
  • Use of some medications: there are remedies capable of causing B12 deficiency through malabsorption, such as metformin and stomach acid reducers.
  • Age: although age itself does not cause a vitamin deficiency, it is estimated that about 60% of people over 60 have low levels of B12.
  • Pernicious anemia: these patients tend to have B12 deficiency due to the lack of intrinsic factor, essential for the transport of the nutrient to the intestine.

What are the symptoms of lack of vitamin B12?

The symptoms of low levels of B12 in the body are many and can be difficult to detect.

But, in general, we can say that vitamin deficiency promotes changes in general disposition, in addition to neurological signs and anemia.

The most common is that the first signs of a lack of vitamin B12 appear through constant tiredness, mood swings, reduced immunity and inflammation of the mouth.

But if vitamin levels reach severely low levels, the body’s functions are affected, and there may even be a reduction in DNA synthesis.

For an overview, here are some other psychological symptoms that may occur with the low amount of vitamin B12 in your body:

    • Irritability
    • Difficulty concentrating
    • Memory changes
    • Depression and severe anxiety
    • Lethargy
    • Mental confusion
    • Hallucinations


In addition to these psychological symptoms, vitamin B12 deficiency in the body can also cause physical problems such as:

  • Drop in immunity
  • Frequent tiredness, even without great efforts
  • Weakening of nails and brittle hair
  • Pallor
  • Sore mouth and stomach pains
  • Megaloblastic anemia (increased red blood cell volume)
  • Pain and tingling in the arms and legs
  • Difficulty moving
  • Vertigo and dizziness
  • Heart attack
  • Stroke
  • Difficulty and reduced vision
  • Urinary and fecal incontinence
  • Fertility problems

What is the importance of B12 in pregnancy?

It is generally agreed that the nutrients ingested by the pregnant woman are fundamental for the baby to form properly and be born healthy.

Vitamin B12, along with folate and iron, plays a very important role in reducing the risks of miscarriage and premature birth, in addition to acting in the formation of baby’s tissues.

That is, in addition to improving the mother’s well-being, B12 favors the baby’s formation, avoiding health risks.



Lactating women also need to pay attention to what they eat. This is because it is through breast milk that the baby will receive nutrients and strengthen the immune system.

Therefore, the ideal is for women to monitor vitamin B12 levels even before they become pregnant.

During the nine months of pregnancy, it is also necessary to reinforce the intake of vitamin sources and carry out medical and nutritional monitoring, making supplementation or dietary adjustments. This, of course, always with medical supervision and guidance.

What is the relationship between vitamin B12 and vegetarianism and veganism?

The lack of nutrients in the body is also associated with dietary restrictions. Among them, vegetarian and vegan.

As vitamin B12 is present, especially in meat and foods of animal origin, the Society of Vegetarianism (SBV) recommends that, if necessary, people should carry out vitamin supplementation.

For vegetarians, it is possible to increase the intake of milk and eggs, especially products that are enriched with vitamins, such as B12.

Vegans, on the other hand, who do not use any animal products, supplementation must be accompanied by a doctor.

When and how to replace vitamin B12?

B12 supplementation can be adopted both to maintain the vitamin levels in your body and to increase the values ​​in case of nutrient deficiency.

Therefore, it is essential that you perform a blood test that will detect the levels of the vitamin in your body. Below, you can see when and how to replace them using supplements depending on your need and purpose:

To maintain rates: If B12 amounts are adequate, feeding should be planned to keep rates stable.

In this case, we recommend that you split the consumption, because, as we have seen, the body is able to absorb only 1.5mcg of B12, usually every 4 or 6 hours.

That is, consuming a meal rich in cobalamin at once will probably be ineffective.


To raise levels: If tests indicate a lack of vitamin B12, you need to raise rates through supplementation.

When the patient has very low levels of B12, the recommended dose can usually reach up to 2,000mcg per day.

What are the benefits of vitamin B12?

As we have seen, there are numerous benefits of vitamin B12 in our body. B12 strengthens the immune system as a whole, reducing the risk of diseases, including cancer.

In addition, this nutrient helps to improve sleep, stabilize the emotional state, reducing symptoms of depression and anxiety.

Another advantage of the correct supplementation of vitamin B12 is that it increases the disposition and helps in the absorption of other nutrients in the body.


Vitamin B12 also strengthens your muscles.

Vitamin B12 also strengthens your muscles. As this nutrient acts on the nervous system, it allows you to exercise more accurately, reducing the risk of injury.

Another advantage is that this vitamin helps in memory and concentration.

B12 also strengthens hair, nails and skin, as it promotes cell reproduction and replacement.

The disadvantage is that those who have dietary restrictions cannot replace or maintain the vitamin levels with food alone, being necessary to use supplements.

The following are the main advantages and disadvantages of Vitamin B12:


  • Improves the immune system, preventing diseases, including cancer
  • Eases depression symptoms
  • Maintains the nervous system
  • Prevents anemia
  • Protects the heart
  • Strengthens nails, hair and skin
  • Gives energy and strengthens muscles


  • Vegetarians and Vegans do not benefit from food supplementation

How much does vitamin B12 cost?

The price of Vitamin B12 varies a lot depending on the manufacturer brand, the composition and the size of the package / number of doses.

In general, you will find Vitamin B12 costing between R $ 15 and R $ 300. Of course, you do not need to buy the most expensive of all. The main thing is that you make an evaluation with your doctor to define the dosage and the period of use that will influence the quantity to be purchased.

Where to buy vitamin B12?

You will find vitamin B12 for sale in pharmacies, supplement stores, department stores and hypermarkets.

But our recommendation is that you make your purchase in online stores like Amazon. So, not only do you guarantee more options to choose from, you also get vitamin B12 from the comfort of your home.



Did you know that the B complex is made up of eight vitamins?

They are: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9) and cyanocobalamin (B12).

In general, these vitamins participate in the breakdown of carbohydrates into glucose, help break down fats and proteins, act on gastric muscles and help absorb nutrients from the intestine.


Purchasing Criteria: What to consider before choosing the best vitamin B12

As we have seen, in order to supplement with vitamin B12, you need to be accompanied by your doctor.

After confirming the need to replace or maintain nutrient rates, you need to understand what differentiates one product from another so that you can make the best purchase.

Therefore, we have selected for you the main factors that must be taken into account before purchasing vitamin B12:

  • Form
  • Composition
  • Active principle
  • Dose
  • Size

In the following, we will explain each of these factors in detail so that you make the best decision and invest in the ideal vitamin B12.


Vitamin B12 can be found in the form of pills, solution, syrup, or injectable, however, the most common is to find B12 in tablets or in liquid form.

The choice here is very personal, as it will depend on practicality and also on ease of ingestion.

In general, the elderly benefit most from B12 in drops. This is because, in this age group it is common that there may be some difficulty in absorbing the vitamin in the stomach.

Vitamin injections are more restricted. In that case, you need a prescription to apply.


After choosing how to ingest the vitamin, we recommend that you consider the composition of the product.

You can choose to purchase the vitamin in its pure composition. In that case, there should be no other ingredients listed in the product’s nutritional table, other than B12.

But you will also find vitamin B12 sold as part of a multivitamin complex, in which other nutrients are included. This will depend on your nutritional needs and your goal.

In both cases, however, watch out for additives such as sweeteners, colors or artificial flavorings, which can have negative effects on your health.

Active principle

It is important that you also note the active ingredient of vitamin B12, which varies according to the manufacturer.

The most popular forms of B12 are methylcobalamin, hydroxocobalamin, adenosylcobalamin and cyanocobalamin.

Cyanocobalamin is a synthetic form of B12 and is one of the most active ingredients found in vitamin supplement formulas.

However, some people respond to it with allergic reactions. Anyone who has kidney problems or is a smoker should also avoid cyanocobalamin.

The World Health Organization, for example, recommends hydroxocobalamin. This is the form of vitamin B12 produced naturally by most microorganisms.

Its biggest advantage over cyanocobalamin is that it has high storage efficiency and does not release toxins.

Methylcobalamin and adenosylcobalamin are the two biologically active forms of vitamin B12 that have the advantage of being stored in the liver satisfactorily.

See below the main characteristics of each active ingredient of vitamin B12:


The dosage of supplements also varies widely, so it is important to take this information into account before purchasing vitamin B12.

The compounds can offer, at each dose, between 10mcg and 5000mcg of vitamin B12. This choice will depend on your doctor’s recommendation.


Also note the size of the package. This will reflect on the duration of use of the vitamin and also on the price of the product.

In general, you will find B12 in bottles that contain between 30 and 400 tablets. If you choose liquid B12 you will find bottles that vary between 60ml and 150ml.



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