Vitamin B12 deficiency: symptoms and risks of a lack of vitamin B12

Vitamins are precious allies of our health. Among them, vitamin B12 occupies a special place, playing an essential role in the functioning of our nervous system, the production of DNA, and the formation of red blood cells. 🔴

Yet despite its importance, you might be among the many people who face a vitamin B12 deficiency without even knowing it. The consequences of a lack of this key vitamin may be subtle at first, but they gradually get worse, profoundly affecting your quality of life.

You may be wondering how to ensure you get enough vitamin B12 and how to recognize the warning signs of a deficiency . Or maybe you're looking for advice on choosing the best forms of vitamin B12 to optimize its absorption and use by your body.

In this article, we tell you everything about vitamin B12 : from identifying the symptoms of a deficiency to understanding the importance of adequate intake , including the best forms of vitamin B12 to fill a gap potential.

Vitamin B12 deficiency: Causes and consequences

Vitamin B12 , or " cobalamin ", is a water-soluble vitamin vital for many processes in our body, including the functioning of the nervous system, the production of DNA (together with vitamin B9 or folic acid), and the formation of Red cells .

Vitamin B12 deficiency occurs when your body does not have enough of this essential vitamin to perform its normal functions. This deficiency can be insidious, developing slowly over several months or even years before symptoms appear.

The main causes of vitamin B12 deficiency include insufficient absorption due to stomach or intestinal disorders , a diet low in animal products 🥩 (main source of B12), prolonged use of certain medications, such as antacids and medications. against type 2 diabetes , and specific medical conditions that affect nutrient absorption (Biermer's disease) (1).

Vegetarians, vegans and the elderly are particularly at risk of developing vitamin B12 deficiency , due to these factors of reduced absorption or insufficient dietary intake.

Left untreated, a lack of vitamin B12 can cause so-called “megaloblastic anemia,” a condition where the body produces abnormally large and ineffective red blood cells (1–3).

Even more serious, prolonged deficiency can cause irreversible damage to the nervous system and brain . Indeed, B12 plays a crucial role in maintaining the myelin sheath, which surrounds and protects the nerves. Without enough B12, myelin deteriorates, leading to neurological problems .

Hence the importance of detecting a vitamin B12 deficiency early in order to intervene quickly to correct the problem!

Symptoms of vitamin B12 deficiency

Symptoms of vitamin B12 deficiency vary greatly from person to person, depending on the extent and duration of the deficiency. At first, signs may be subtle and easily confused with symptoms of other medical conditions.

Without correcting the deficiency, the situation worsens and symptoms appear . Here are some of the most commonly seen (1.3–5): 👇

• Fatigue : persistent, not improving with rest. This feeling of weariness is due to anemia, a lack of healthy red blood cells to carry oxygen around the body.
• Neurological symptoms : tingling, tingling sensation in the hands or feet (peripheral neuropathy), difficulty walking, loss of balance, and memory problems may occur, reflecting the impact of the deficiency on the nervous system.
• Mood Alterations : Depression, anxiety, and mood swings are sometimes the only signs of a vitamin B12 deficiency.
• Digestive problems : nausea, diarrhea or constipation, loss of appetite.
• Cardiovascular symptoms : Anemia associated with vitamin B12 deficiency (megaloblastic anemia) can cause shortness of breath, dizziness and heart palpitations.
• Problems during pregnancy : Vitamin B12 deficiency in pregnant women could increase the risk of certain adverse events such as spontaneous abortion (miscarriage), fetal growth retardation, neural tube defects (problems with the brain or spinal cord of the fetus).

If you experience one or more of these symptoms, see your doctor for a thorough evaluation (including measuring blood levels of vitamin B12) and, if necessary, treatment to correct the deficiency and restore vitamin B12 reserves. body.

Sources rich in vitamin B12

A sufficient intake of vitamin B12 is crucial to avoid deficiencies that can lead to severe symptoms, such as fatigue, neurological problems, memory problems… Since our body cannot produce this vitamin, we must 'obtain from our diet or supplements .

Animal sources of vitamin B12

Vitamin B12 is mainly found in the following animal sources:

• 🥩 Red meats and poultry: beef, pork, lamb, and poultry are good sources of B12. Organ meats, liver in particular, are exceptionally rich in this vitamin.
• 🐠 Fish and seafood: Oily fish like salmon, mackerel, herring, and tuna, as well as seafood, including oysters, mussels, and crabs, offer significant amounts of vitamin B12.
• 🥛Dairy: Milk, cheese, and yogurt also contain this vitamin, providing a valuable option for vegetarians.
• 🥚 Eggs: although their B12 content is lower than that of meat and fish, eggs are an interesting source of this vitamin, especially for vegetarians.

Plant sources of vitamin B12

As you can see, vitamin B12 is mainly found in foods of animal origin . Thus, vegetarians — who do not indulge in any animal products (including eggs and dairy) — are particularly at risk of developing a deficiency in this vitamin . Fortunately, there are other options: fortified foods and supplements .

Foods enriched with vitamin B12 are represented by plant milks (soy, almond), vegan dairy products (vegan yogurts and cheeses), vegan “meats”, cereals and certain types of nutritional yeast. These options can contribute significantly to the recommended daily B12 intake for vegans and people who have difficulty absorbing vitamin B12.

As for vitamin B12 supplements , whether in the form of tablets, capsules or injections, they are an excellent solution to prevent the risk of deficiency in people at risk (vegans, elderly people, people suffering from digestive malabsorption). , anorexics…).

Endogenous source of vitamin B12

Our intestinal microbiota is capable of producing vitamin B12. However, this synthesis occurs primarily in the colon , a region where absorption of vitamin B12 cannot occur efficiently because vitamin B12 is absorbed primarily in the terminal ileum of the small intestine (after forming a complex with the intrinsic factor secreted by the parietal cells).

Furthermore, although our own gut bacteria produce vitamin B12, the amount they synthesize is generally not available for use by our bodies .

Thus, the site of production (colon, therefore non-absorbable) and the small quantity produced are the two reasons why this endogenous source of vitamin B12 does not contribute significantly to our daily intake. This is why it is essential to obtain this vitamin through diet and, if necessary, through supplementation .

The different forms of vitamin B12 and their bioavailability

Vitamin B12 comes in several forms, each with a specific function in the body. The choice of the form of vitamin B12 can influence the effectiveness of its absorption and use by the body, especially with regard to preventing or correcting a deficiency:

Cyanocobalamin

It is the most stable form and most commonly used in supplements and fortified foods. Although its absorption is good, the body must first convert it to active forms (methylcobalamin or adenosylcobalamin) to use it, which requires additional enzymatic conversion.

Less expensive to produce, it is often present in most food supplements. However, it is considered the least effective for quickly correcting a deficiency due to the required conversion process.

According to the authors of this study published in 2017 :

Methylcobalamin

This form of vitamin B12 is already in an active condition , meaning it can be directly used by the body without conversion .

Methylcobalamin is particularly important for nervous system health and the production of brain chemicals that influence mood and sleep.

✨ It is considered one of the best forms to use in cases of vitamin B12 deficiency , due to its absorption and direct use by the body.

The authors of this study sum it all up in their conclusion:

Adenosylcobalamin

Also an active form of vitamin B12, adenosylcobalamin is essential for energy metabolism in cells. It plays a key role in converting fats and proteins into energy.

💪 This form is particularly effective in supporting cellular energy , making it a valuable option for correcting or preventing B12 deficiencies.

Hydroxocobalamin

Found naturally in foods, hydroxocobalamin is easily converted by the body into active forms of vitamin B12 . It has a longer half-life in the body , which may prolong its beneficial effect.

It is often used in injections to treat B12 deficiency , providing an effective solution for individuals with absorption issues.

Thus, to correct or prevent a vitamin B12 deficiency, the methylcobalamin , adenosylcobalamin , and hydroxocobalamin forms are particularly recommended. These forms are more directly usable by the body and may be more effective in quickly restoring healthy B12 levels, especially in individuals with absorption difficulties or increased needs.

Cyanocobalamin can be useful, especially as an affordable (cheaper) source of B12, but active forms are more effective.

Preventing and managing a lack of vitamin B12

Prevention and management of a lack of vitamin B12 are crucial aspects of maintaining good health, especially for certain populations at risk. Here are effective strategies to achieve this:

Identification of situations at risk of nutritional deficiency

Must be particularly vigilant regarding their vitamin B12 intake: 👇

• Old people ;
• Strict vegetarians or vegans ;
• Flexitarians (people who reduce their meat consumption without switching to a vegetarian or vegan diet);
• People in precarious situations [not consuming enough foods of animal origin for financial reasons];
• Individuals suffering from diseases affecting digestive absorption of nutrients [such as celiac disease or Crohn's disease].

If you are part of one of these populations at risk of vitamin B12 deficiency, you should consult your therapist to adopt appropriate preventive measures.

Increased dietary intake of vitamin B12

Include rich sources of vitamin B12 in your diet to protect yourself from deficiency. This mainly concerns animal products such as meat , fish , dairy products , and eggs .

👉 For vegans and those who prefer to avoid animal products, opting for foods enriched with vitamin B12 , such as certain plant-based milks , breakfast cereals , and meat substitutes , can be a good alternative, but preferably under the advice of a doctor or nutritionist.

Consider complements

Vitamin B12 supplements may be especially helpful for those who cannot get enough B12 through diet alone.

Active forms of B12, such as methylcobalamin, adenosylcobalamin, and hydroxocobalamin, are preferred for their better absorption and effectiveness.

Talk with a healthcare professional to determine the best form and dosage for your individual needs.

Regular monitoring of B12 levels

For people at risk, regular monitoring of vitamin B12 levels through blood tests can help detect a deficiency before it becomes symptomatic. This is especially important for older adults and those with medical conditions affecting nutrient absorption.

Conclusion

Here are the key points to remember about lacking vitamin B12: 👇

• Vitamin B12 is crucial for many bodily functions, from nervous system health to the formation of DNA and red blood cells.
• A B12 deficiency can lead to serious health problems and long-term complications.
• Our body is incapable of producing vitamin B12 [apart from a tiny synthesis by the digestive flora], which is why it is essential to provide it through food or supplementation.
• The main sources of vitamin B12 are animal foods such as meats, organ meats, seafood, dairy products and eggs.
• Elderly people or people who do not consume enough of these animal products, as well as those suffering from certain medical conditions that reduce digestive absorption [Crohn's, celiac disease, Biermer, etc.] are particularly at risk of vitamin B12 deficiency.
• Active forms of B12, such as methylcobalamin, adenosylcobalamin, and hydroxocobalamin, provide optimal absorption and are preferable for preventing or treating deficiency.

FAQs

References

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