Imagine a day where fatigue disappears, your mind is clear, and every task seems effortless. This isn't just imagination; it's the potential power of vitamin B12, an essential nutrient that supports your body's most vital functions . From energy production to nerve health, vitamin B12 is a cornerstone of well-being.
What is vitamin B12?
Vitamin B12, also known as cobalamin , is a water-soluble vitamin that is essential for:
- Your cell division
- Your nervous health
- The production of your red blood cells is.
It also plays a major role in the breakdown of homocysteine, a process important for heart health . Unlike some nutrients, your body cannot produce vitamin B12 itself —it must be obtained from food or supplements and is stored primarily in the liver, albeit in limited quantities.
The small vitamin with a big impact
Vitamin B12 is like the electricity that illuminates your inner lamp . Whether you're following a vegan lifestyle, under stress, or experiencing hormonal changes, vitamin B12 is essential for stability and strength .
Where is vitamin B12 found?
You might rightly be asking yourself, " Where can I find vitamin B12? " The answer usually leads to animal products, which makes it an important and sometimes challenging topic, especially for vegetarians and vegans. The most important sources include:
- Fish & Seafood: Abundant options such as herring, salmon and mackerel.
- Meat & Offal: Liver is particularly rich.
- Dairy products & cheese: Your daily intake can increase your vitamin B12 intake.
- Eggs: An easily accessible option for many.
Plant foods generally do not contain active vitamin B12 unless they are fortified, such as some plant milks and specialty food products .
Detecting a vitamin B12 deficiency
A vitamin B12 deficiency is often not noticed until late , as the body has large reserves in the liver, and symptoms only appear when the deficiency is advanced. The most common symptoms include:
- Tiredness & exhaustion
- Concentration problems & brain fog
- Tingling or numbness in hands and feet
- Pale skin & shortness of breath
- Mood swings & depressive moods
- Burning tongue & loss of appetite
- Memory disorders
- Hair loss
- Depressive mood up to depression
- Unsteady gait & increased tendency to fall (in some cases paralysis may also occur)
- Headache
You should not ignore such symptoms, as a long-term deficiency can lead to irreversible nerve damage.
Causes of vitamin B12 deficiency
A deficiency can have various causes, including a lack of the protein intrinsic factor, which is important for transport within the body, and chronic inflammation of the stomach or intestines . Taking certain medications or regular alcohol consumption can also impair vitamin B12 absorption. Vegans and vegetarians are particularly at risk, as vitamin B12 is primarily found in animal products. And with age , the ability of the gastrointestinal tract to effectively absorb vitamins decreases.
Prevention through proper nutrition
A proper diet can prevent vitamin B12 deficiency. Older people should regularly include meat, milk, and eggs in their diet, while vegans should focus on ensuring adequate levels of vitamin B12 through fortified foods or supplements .
Treatment & diagnosis of the deficiency
If a vitamin B12 deficiency is suspected, it is important to seek medical advice . Blood tests can measure vitamin B12 levels in the body. Holotranscobalamin , which indicates the status of the active vitamin, is particularly valuable. Vitamin supplements should only be taken after a deficiency has been confirmed by a doctor to avoid a possible overdose , which could be associated with health risks such as an increased risk of lung cancer.
Correcting the deficiency: The road to recovery
The path to restoring vitamin B12 levels depends on the severity of the deficiency:
- Mild deficiency: Often corrected with oral supplements in 4–8 weeks.
- Advanced cases: High-dose oral or sublingual options may be required for 2–3 months.
- Severe cases (Neurological): Medical supervision with injections may take several months.
Daily requirements & supplementation
For adults, the German Nutrition Society (DGE) recommends a daily intake of 4 µg , with an increased need during pregnancy and breastfeeding. Dietary supplements often contain higher doses, as only a fraction is absorbed. Reassuringly, B12 supplements are well tolerated, and excess amounts are simply excreted in the urine.
Your most frequently asked questions about vitamin B12
- Where is vitamin B12 found? Mainly in animal products such as meat, fish, eggs, and dairy products.
- Why is a deficiency dangerous? It's the deficiency, not the vitamin, that poses health risks.
- How quickly do supplements work? Initial improvements can occur within 1–2 weeks, while neurological recovery may take longer.
- How much vitamin B12 should you take daily? 4 µg is recommended, although supplements often contain between 250 and 1,000 µg.
- How long does it take to correct a deficiency? Depending on the severity, this can take anywhere from four weeks to several months.
Science needs sources
- German Nutrition Society (DGE): Vitamin B12
- NIH Fact Sheet: Vitamin B12
- Allen, L.H. (2008). Causes of vitamin B12 and folate deficiency , Food and Nutrition Bulletin
- Stabler, S. P. (2013). Vitamin B12 deficiency , N Engl J Med