Vitamin B12: Occurrence, Dosage, and Benefits

Vitamin B12: Occurrence, Dosage, and Benefits

Vitamin B12 plays a crucial role in maintaining the proper functioning of the human body. Not only is it responsible for the normal development of nerve cells, but it also influences cell division, nucleic acid synthesis of DNA and RNA, and protein production involved in their structure. Additionally, it impacts the hematopoietic, digestive, and nervous systems, with deficiencies potentially suggesting psychological disorders.

Vitamin B12 Sources

Vitamin B12 is predominantly found in animal-based products. It is almost entirely absent in plant-based foods, including vegetables and fruits. To provide the body with the highest amount of this vitamin, consume:

  • Meat (beef, poultry, pork)
  • Organ meats (e.g., kidneys)
  • Fish (sardines, salmon, herring, trout, tuna, mackerel, pike)
  • Seafood (crustaceans, lobsters, oysters)
  • Dairy (milk, yellow cheese, yogurts, blue cheese)
  • Eggs
  • Mushrooms (containing relatively small amounts of B12)

In plant-based foods, vitamin B12 is scarce, although trace amounts can also be found in yeast. External supplementation is therefore essential for vegetarian diets, as obtaining sufficient amounts of this vitamin from plant-based foods alone is not possible.

Dosage and Recommended Intake

Proper supplementation of vitamin B12 is crucial, as excessive consumption of animal-based products can lead to the formation of undesirable metabolic byproducts. Daily vitamin B12 intake recommendations are:

  • 2 micrograms for healthy adults
  • 2.2 micrograms for pregnant women
  • 2.6 micrograms for breastfeeding mothers

Although most people's diets are rich in meat products, many still suffer from vitamin B12 deficiency. Symptoms of this deficiency include pale skin, painful sores at the corners of the mouth, general weakness, headaches, dizziness, loss of taste and appetite, tongue inflammation, weight loss, nausea, diarrhea, or constipation. Vitamin B12 deficiency also has several negative effects on the nervous system, such as tingling in fingertips, loss of vibration and deep sensation, unstable gait, weakened vision, and seizures.

Mental Health and Vitamin B12 Deficiency

Vitamin B12 deficiency is rarely considered a cause of symptoms characteristic of mental disorders. Depressive disorders, psychomotor agitation, hypomanic syndromes, personality and behavioral changes, psychotic disorders, memory impairment, and varying degrees of cognitive disturbances may all result from a deficiency in vitamin B12. Before starting pharmacological treatment, it is essential to replenish any vitamin deficiencies in the body.

Vitamin B12 Overdose

Vitamin B12 overdose is a rare occurrence. Even daily intake of large doses, such as 1 mg, does not lead to overdosing. Excess vitamin B12 is either stored in the body or excreted through bile and feces. However, if taken with high doses of vitamin C, it may cause nosebleeds, ear bleeding, and dry lips.

Benefits: Supporting Vital Body Systems

Vitamin B12 plays a significant role in the proper functioning of the body's digestive, nervous, and circulatory systems. It aids in the creation of red blood cells, directly preventing anemia. Vitamin B12 also enables nucleic acid synthesis in cells, particularly in bone marrow, which is responsible for producing blood cells. In the nervous system, it strengthens the myelin sheath protecting nerve cells and contributes to neurotransmitter formation, thereby facilitating information transfer between cells. This improves memory retention, accelerates learning, and increases concentration. Vitamin B12 also participates in carbohydrate, protein, and lipid metabolism. It not only stimulates appetite but also 

activates metabolic processes. It directly affects muscle growth and performance and also enhances iron absorption.

Vitamin B12 is especially important for children during their growth period and for women during menopause. However, due to its wide range of actions, external supplementation is vital, as there can be many causes of deficiency - not necessarily limited to vegetarian or vegan diets.

Supplementation and Lifestyle Choices

To prevent vitamin B12 deficiency, consider incorporating vitamin B12-rich foods into your daily diet or taking supplements, especially if you follow a vegetarian or vegan diet. If you suspect that you may have a deficiency, consult a healthcare professional for proper diagnosis and treatment. They may recommend appropriate vitamin B12 supplements or other treatments based on your individual needs and medical history.

Additionally, maintaining a healthy lifestyle by engaging in regular physical activity, managing stress, and ensuring adequate sleep can contribute to overall health and well-being. These factors can also improve the absorption and utilization of vital nutrients, such as vitamin B12.


Vitamin B12 is an essential nutrient that plays a pivotal role in the proper functioning of the body's digestive, nervous, and circulatory systems. Obtaining adequate amounts of this vitamin is crucial for overall health, as deficiencies can lead to various physical and mental disorders. Incorporate vitamin B12-rich foods into your diet, and consider supplementation if necessary, to maintain optimal health and well-being.

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