Vitamin B12 holds a special place in the B-complex: Not only is it the only B vitamin that can be stored in the body for long periods of time, but it is also the only B vitamin found in significant amounts exclusively in animal-based foods. We’ll show you how to recognize a vitamin B12 deficiency, who’s most likely to develop one, and what you can do about it. There are a few things to keep in mind when taking a vitamin B12 supplement. Not only does the dosage play an important role, but so does the chemical form in which the vitamin B12 is present. For optimal results, you should opt for a natural and metabolically active form of B12.
Everything You Need to Know About Vitamin B12
Vitamin B12 Deficiency
The causes of vitamin B12 deficiency can vary widely. Often, only a blood test can determine whether you have a vitamin B12 deficiency.
One of the main causes of vitamin B12 deficiency is an unbalanced diet, as is often the case with vegans (and vegetarians). Increased physical activity can also contribute to a vitamin B12 deficiency. Just like vegans and vegetarians, athletes should have their vitamin B12 levels checked at regular intervals and, if necessary, adjust their diet or consider taking a dietary supplement.
People with chronic intestinal diseases (such as ulcerative colitis or Crohn's disease) may also need to take a dietary supplement because they may have poor absorption or inadequate utilization of vitamin B12.
What is vitamin B12?
Vitamin B12 is a very complex molecule produced only by microorganisms such as bacteria and algae. Some strains of bacteria in the human gut also produce vitamin B12—but they do so for their own needs and mostly in the large intestine, where it is of little use to the human body. Humans absorb most of their vitamin B12 in the small intestine.
Vitamin B12 is one of a total of eight B vitamins that are essential for our bodies. “Essential” means that we depend on this vitamin to function normally. The fact that this B vitamin is water-soluble—meaning our bodies don’t store it and we must consume it daily—highlights its importance.
Vitamin B12 plays a role in many metabolic processes; it is also often blamed for chronic fatigue, difficulty concentrating, and low energy. People who eat a varied diet and choose wholesome, natural foods that are gently cooked or eaten raw usually do not need to worry about a vitamin B12 deficiency.
However, this does not apply to vegetarians and vegans, whose diets consist largely or entirely of plant-based foods. In these cases, it is recommended to take this B vitamin as a dietary supplement, since it is found almost exclusively in animal-based foods.
Vitamin B12 Deficiency — Symptoms
Because a vitamin B12 deficiency is often accompanied by nonspecific symptoms, it frequently goes unnoticed for a long time. Many people frequently complain of fatigue, but they do not immediately attribute their symptoms to a vitamin B12 deficiency. These symptoms are often linked to stress, seasonal changes, a disrupted day-night rhythm, or lack of sleep.
Nevertheless, it is not only vegans and vegetarians but also athletes and older adults who are affected by vitamin B12 deficiency.
These are the symptoms of vitamin B12 deficiency:
- Fatigue
- Difficulty concentrating
- Drive System Malfunctions
- increased need for sleep
- Sensory disturbances in the hands, feet, arms, and legs
- Weakness
- Dizziness
- Changes in the Mucous Membranes
- Impaired movement and coordination
Vitamin B12 — Daily Requirements & Food Sources
Daily Requirement
The DGE (German Nutrition Society) recommends that adolescents and adults consume 4 micrograms of vitamin B12 daily. For pregnant women and breastfeeding mothers, the recommended intake is 4.5 and 5.5 micrograms of vitamin B12, respectively.
For those who follow a mixed diet, there are many ways to meet their vitamin B12 needs through their diet. Below, we’ll show you which foods are particularly rich in vitamin B12.
Food
Fortunately, there are many foods that contain vitamin B12. As you already know, this vitamin is found primarily in animal-based foods, which is why vegans and vegetarians are often deficient and exhibit symptoms of deficiency. Although trace amounts of vitamin B12 are found in tubers and root vegetables as well as in some fermented products, such as tempeh and sauerkraut, these sources are not sufficient to meet the body’s vitamin B12 needs.
However, people who eat a varied diet should have no trouble meeting their daily requirement of four micrograms, thanks to the wide variety of foods available. Below, we’ll introduce you to the best foods that are particularly rich in vitamin B12.
Vitamin B12 in Foods: These Are the Best Sources of Vitamin B12
(Vitamin B12 content per 100 grams of food)
- Beef liver: 65 micrograms
- Caviar: 20 micrograms
- Mackerel: 19 micrograms
- Oyster: 15 micrograms
- Herring: 8.5 micrograms
- Beef: 5 micrograms
- Trout: 4.5 micrograms
- Tuna: 4.3 micrograms
- Sea bass: 3.7 micrograms
- Emmental: 3.1 micrograms
- Camembert: 3.1 micrograms
- Egg: 1.8 micrograms
- Plaice: 1.5 micrograms
- Cream cheese: 0.8 micrograms
- Grated cheese: 0.7 micrograms
When might a vitamin B12 supplement be necessary?
For vegans, it can generally be beneficial to take a vitamin B12 supplement, since they do not consume animal products and a vitamin B12 deficiency is inevitable in the long term. In addition, people who are physically active, under a great deal of stress, or chronically ill have a higher need for vitamin B12, which they often cannot meet through diet alone.
Anyone who wishes to take vitamin B12 as a dietary supplement should choose a product made from natural ingredients as much as possible. It is important to ensure that the supplement contains the so-called MHA formula. This refers to the bioactive forms of vitamin B12: methylcobalamin, hydroxocobalamin, and adenosylcobalamin (MHA). The body can use these natural, bioactive forms of vitamin B12 immediately, without having to convert them first.
Vitamin B12 — Effects
Vitamin B12 is very important for our bodies because it performs many important functions in our metabolism.
Below, we'll show you the most important functions of vitamin B12, which explain why this vitamin is so important for our bodies.
Vitamin B12
...is important for the normal functioning of the immune system
...supports the production of red blood cells
…promotes healthy energy metabolism
...promotes normal homocysteine metabolism
...contributes to the normal functioning of the nervous system
...supports mental functions
...helps reduce tiredness and fatigue
...is important for cell division
Cobalamin – The Form of Vitamin B12 Is Crucial
Like all vitamins, vitamin B12 exists in several chemically related forms. These are grouped under the umbrella term “cobalamins.” All of them contain the trace element cobalt as their central molecule.
The three natural forms—hydroxycobalamin, adenosylcobalamin, and methylcobalamin—are particularly important for humans. Hydroxycobalamin is a compound synthesized by microorganisms. It does not yet function as a vitamin, but it binds exceptionally well to transport molecules in the blood and is therefore the optimal storage form for vitamin B12.
The only two forms (coenzymes) that are immediately metabolically active are adenosylcobalamin and methylcobalamin. Hydroxycobalamin is converted into one of these two compounds as needed. The same applies to cyanocobalamin—a synthetic compound used to fortify foods and in dietary supplements.
Important Forms of Vitamin B12
| of course | active | ||
|---|---|---|---|
| Adenosylcobalamin | yes | yes | most common form in tissues and organs |
| Methylcobalamin | yes | yes | the most common form in the blood and brain |
| Hydroxycobalamin (Hydroxocobalamin) | yes | no | form synthesized by microorganisms, physiological form |
| Cyanocobalamin | no | no | synthetic form |
Vegans and Vitamin B12
Vegans often have a vitamin B12 deficiency because their diet consists exclusively of plant-based foods. It is simply nearly impossible for vegans to meet their daily vitamin B12 needs through diet alone.
What many people don’t know: Vegans are by no means the only group at risk of having trouble getting enough vitamin B12. A vitamin B12 deficiency often affects more people than you might think. Those affected include not only vegetarians, whose diets consist mainly of plant-based foods. Athletes, pregnant women, and people with chronic gastrointestinal disorders can also be affected by a vitamin B12 deficiency.
Athletes, in particular, have an increased need for vitamin B12, which is necessary for maintaining physical performance. Did you know that stress is one of the biggest nutrient depleters? On top of that, alcohol and nicotine can contribute to a faster depletion of vitamin B12.
Conclusion
Vitamin B12 is considered a critical vitamin because it is found almost exclusively in animal-based foods. Vegans therefore cannot obtain this vitamin through their diet, which is why taking a vitamin B12 supplement is recommended. In addition, athletes, pregnant women, and people with chronic illnesses have higher vitamin B12 requirements, which may necessitate the use of a dietary supplement.
Sources
- Dr. Udo Böhm, Dr. Dr. Claus Muss: Rational Therapy in Micronutrient Medicine, UNI-MED Verlag Aktiengesellschaft, Bremen, 2001, 1st edition, ISBN 978-3-8374-1275-8.
- Uwe Gröber: Micronutrients: Metabolic Tuning—Prevention—Therapy. Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart, 2012, 3rd edition, ISBN 978-3-8047-2615-4.
- https://www.ugb.de/ernaehrungsberatung/vitamin-b12-manchmal-wird-es-knapp/?cobalamin-vitamin-b12
