5 minYou may have heard of it in the context of veganism or seen it listed on supplement bottles. But did you know that B12 plays an indispensable role in your body? This vitamin helps maintain your energy levels, supports your nervous system and is important for the production of red blood cells. So it's not a luxury! In this article, you can read about where to find vitamin B12, why it is so important and when it might be wise to take a supplement.
In this article, you can read about
- What vitamin B12 is and why it is important.
- The different forms of vitamin B12 and which ones are best absorbed.
- How a vitamin B12 deficiency develops and how to recognise it.
- The recommended daily amounts and when a supplement may be necessary.
What is vitamin B12?
Vitamin B12, also known as cobalamin, is one of the eight vitamins in the B complex and plays a crucial role in your health. This vitamin is known for its versatile functions in the body. Vitamin B12 is a water-soluble vitamin that is essential for the production of red blood cells, maintaining a healthy nervous system and the metabolism of fats and proteins.
It is also directly involved in the creation of DNA, the genetic material of your cells. It also helps in the formation of haemoglobin, the protein in your blood that transports oxygen to your tissues. A vitamin B12 deficiency can lead to anaemia and neurological problems, such as tingling or numbness in the hands and feet. So it's quite an important vitamin!
Forms of vitamin B12
Vitamin B12 comes in various forms. The most important are adenosylcobalamin and methylcobalamin, which are the active forms that your body can easily use. Fortified foods and many supplements often contain hydroxocobalamin or the synthetic form, cyanocobalamin.
- Methylcobalamin: is a natural form of B12 that is easily absorbed by your body. It helps your brain and nerves to function properly and plays a role in converting homocysteine into methionine, which is important for your immune system and proteins.
- Adenosylcobalamin: is another active form of B12 that is important for your energy levels and nervous system.
- Cyanocobalamin: is an artificial and stable form of B12 that is widely used in supplements. Your body must first convert this form into an active form, which can be less efficient, especially in older people or those with stomach problems.
- Hydroxocobalamin: is often used for injections because it stays in your body longer and helps to quickly correct a severe B12 deficiency.
Which form is best absorbed
The best forms of vitamin B12 that your body easily absorbs are methylcobalamin and adenosylcobalamin (also known as coenzyme B12). These active forms no longer need to be converted by your stomach and intestines, so your body can use them immediately!
Why is vitamin B12 important?
Vitamin B12 is essential for your blood and nerves. A deficiency can cause your blood values to drop and make you feel very tired. This vitamin helps your body convert carbohydrates, proteins and fats from your diet into energy. Vitamin B12 also supports many other processes in your body, such as:
- Reducing fatigue and tiredness
- Helping to produce red blood cells
- Contributing to fitness
- Activating your body's natural energy
- Helping the immune system to function normally
- The formation of red blood cells, helping to produce red blood cells
- Good for memory, concentration, learning performance and mood
- Mental resilience and clarity
- Contributes to the proper functioning of the nervous system
- Normal energy metabolism
- Normal homocysteine metabolism
- The process of cell renewal
- Contributes to good resistance
Vitamin B12 in food
People who follow a vegan or vegetarian diet often take a vitamin B12 supplement. This is not without reason, as vitamin B12 is obtained from animal products, including meat, fish, dairy products (milk) and eggs. Vitamin B12 is sometimes added to soya yoghurt and meat substitutes, but this is often not sufficient. Would you like to know exactly which products contain vitamin B12? Read our article on foods that contain B12!
Why vitamin B12 in supplements is always high
You may have noticed that vitamin B12 supplements often contain much higher doses than the recommended daily allowance. This is because the body absorbs less vitamin B12 from supplements than from food. In general, only 10-50% of the B12 from a supplement is actually absorbed.
The absorption rate varies depending on several factors, such as the dose of the supplement (higher doses are absorbed less efficiently), gut health, the form of the supplement (absorption through the oral mucosa may be more efficient than through the intestines), the combination of foods you are eating at the time, medication use and the overall health of the person. How often you take the supplement also plays a role.
- For people with a vitamin B12 deficiency, high and frequent doses are very useful for quickly replenishing the deficiency. Once the deficiency has been resolved and there are no longer any problems with absorption, they can switch to lower doses to maintain vitamin levels.
- For people who have problems absorbing vitamin B12 from food, for example due to a deficiency of intrinsic factor (a protein necessary for absorption in the intestines), high doses may still be necessary. This often occurs when using antacids or certain medical conditions.
Vitamin B12 deficiency
There are several reasons why you may develop a vitamin B12 deficiency. If you eat little or no animal products, you are at greater risk. But even if your body absorbs B12 poorly due to stomach problems, such as an infection with Helicobacter pylori or the use of antacids, this can also be a problem. Diseases such as Crohn's disease or coeliac disease can also interfere with absorption in the small intestine.
Older people often need more vitamin B12 because their absorption capacity decreases. In addition, certain medications, such as antibiotics, antidepressants and the contraceptive pill, can affect the absorption of B12. Even stress can play a role in reducing absorption. The dangerous thing about this is that you do not quickly notice a B12 deficiency.
Vitamin B12 is the only water-soluble vitamin that is stored in the body. However, if a deficiency develops because no animal products are included in the diet, blood levels will drop. A deficiency can be detected by a blood test. High doses of vitamin B12 may be necessary to treat deficiencies.
You can recognise a severe vitamin B12 deficiency by the following symptoms:
- Numb fingers and toes
- Tingling, movements become less precise
- Problems with your balance
- Psychological problems
- Anaemia
- Fatigue
Under-reported psychological complaints
Although the physical symptoms of vitamin B12 deficiency are often clear, the psychological effects sometimes receive less attention. However, there is a strong link between B12 deficiency and mental functions and health. If you have a B12 deficiency, you may experience an increased risk of depression. This is because low B12 levels increase the amount of homocysteine in your blood, which can cause DNA damage and cell death. A B12 deficiency can also lead to mental disorders such as psychosis, dementia or confusion (in the elderly), mood disorders and anxiety disorders.
Vitamin B12 excess
There is little chance of adverse effects if you consume too much vitamin B12. Your body ensures that excess amounts are not absorbed but are immediately excreted in your urine. Therefore, no upper limit has been set for vitamin B12 intake.
Recommended amount
Recommended daily amount for adults:
- Adult women: 2.8 mcg
- Pregnant women: 3.3 mcg
- Breastfeeding women: 3.8 mcg
- Adult men: 2.8 mcg
Recommended daily amount for babies, toddlers and children:
- From 0-6 months: 0.4 mcg
- From 6-11 months: 0.5 mcg
- From 1-3 years: 0.7 mcg
- From 4-8 years: 1.3 mcg
- From 9-13 years: 2.0 mcg
- From 14-17: 2.8 mcg
There is no acceptable upper limit for vitamin B12.
Do you need a vitamin B12 supplement?
Do you follow a vegetarian or vegan diet, or do you eat little meat? Then you need to take a vitamin B12 supplement to maintain the level in your blood. A vitamin B12 deficiency occurs when you do not eat animal products or when you have too little intrinsic factor. Intrinsic factor is a protein that is necessary for the absorption of vitamin B12 from food. If you have a deficiency of this intrinsic factor, your body will not be able to absorb sufficient B12.
Older people also often have a vitamin B12 deficiency because their stomach acid production decreases. This also reduces the absorption of vitamin B12. In rare cases, certain medications can also cause a vitamin B12 deficiency.
