Not enough vitamin B12? These groups are at risk

To be well, the human body needs substances that support its physiological functions These include so-called biofactors, that is, vitamins, minerals, amino acids, fatty acids and secondary plant substances. However, many of these can’t be produced by the body itself, or at least not in sufficient quantities, which is why nutrition is key.

By eating, people supplement nutrients they’d otherwise lack and, in doing so, avoid a deficiency that could lead to health problems. One of said nutrients is vitamin B12. Vitamin B12 is ingested via food only, making us all the more susceptible to deficiency.

What are the dangers of vitamin B12 deficiency?

The Society for Biofactors divides vitamin B12 deficiency into three categories: mild, severe and pregnancy-related. Each type leads to distinct symptoms:

• Mild deficiency: tiredness, exhaustion, poor performance and poor memory

• Severe deficiency: depression, dementia, cardiovascular diseases

• Pregnancy-related deficiency: developmental disorders and delayed foetal development of the child

Unfortunately, awareness of vitamin B12 isn’t quite as widespread as that of typical vitamins like A, B, C and D. As a result, a deficiency isn’t always recognised.

Who’s especially at risk?

As a rule of thumb, people who eat a standard diet shouldn’t have any deficiencies. So says German consumer magazine «Ökotest», which tested 29 vitamin B12 supplements (page in German). In this context, a «standard» diet is one that includes animal foods such as dairy products, meat, fish and eggs. This is key, as only foods of animal origin contain enough vitamin B12 to meet human requirements, even though they’re not very high, and our bodies can store the vitamin.

The German Nutrition Society (DGE) emphasises that those who follow a vegan diet require targeted supplementation, as their diet provides the body with too little or no vitamin B12. You can find the reference values on the DGE website (in German).

Further causes of vitamin B12 deficiency

There are also other causes of vitamin B12 deficiency requiring treatment:

• Frequent intake of medication (especially in older people; for example, gastric acid blockers, which also affect vitamin B12 absorption)

• Diabetes (studies have shown that taking metformin increases the risk of vitamin B12 deficiency up to threefold)

• Stomach diseases, irritable bowel syndrome and kidney problems (for example due to fish tapeworm infestation, intestinal parasites or gastritis)

Pregnant women not only have an increased need for protein, but also for vitamin B12 (page in German). Experts therefore strongly recommend regular blood tests, continuing into breastfeeding. According to the «Deutsche Apotheker-Zeitschrift» (German pharmacists’ journal), the general daily vitamin B12 requirement for pregnant and breastfeeding women increases from 4.0 µg (microgrammes, 1 millionth of a gramme) to 4.5–5.5 µg.

What is vitamin B12 and why do we need it?

Vitamin B12 is a collective term that refers to different compounds in the human body with the same basic chemical structure, also known as cobalamin. Cobalamin is indispensable. Together with folic acid, for example, it’s involved in all growth processes, ensuring that the body’s cells renew and multiply (page in German) during DNA synthesis. Cobalamin’s other functions include the formation of red blood cells (a deficiency may therefore lead to anaemia) as well as essential tasks within the central nervous system, for example in the regeneration of the insulating layer that encases nerve fibres.

Vitamin B12 deficiency: mild symptoms often fly under the radar

Determining that your body is lacking in important substances is easier said than done. In the case of vitamin B12 this is particularly difficult, as the onset of a deficiency often only becomes noticeable after years. Why’s that? Well, its mild symptoms (see above) are often ignored, misattributed or simply overlooked. Especially in stressful situations, people tend to dismiss tiredness, poor performance and memory or symptoms of exhaustion and take them lightly.

But as stated in a publication in the specialist journal CME, in the case of a chronic B12 deficiency that’s only diagnosed very late, the risk of irreversible consequential damage increases. All the more reason why you should take signs such as low blood pressure, cramps, tingling skin and trembling hands, blurred vision, tiredness, depressive moods, dizziness and poor concentration seriously and consult a doctor early on.

What can you do to avoid deficiency?

Supplementation is key, especially for anyone with a meat- and animal product-free diet. The reference values mentioned above were adjusted in 2019 and are now slightly higher than before. According to the German Nutrition Society, the recommended daily dose is now 4 μg for adults and 4.5–5.5 µg for pregnant and breastfeeding women. However, as «Ökotest» (page in German) points out in its analysis, many supplements that can be found in pharmacies or drugstores contain too high a dose. For most people, this isn’t dangerous, as the body can simply excrete any excess Vitamin B12. But there’s evidence that a very high B12 content in the body may promote lung cancer, especially in former smokers. Either way, there’s no benefit to overconsumption.

Want to know more about Vitamin B12 and other B vitamins? Check out this overview by science editor Anna Sandner:

Interested in other vitamins, minerals and fibre? Check out this article: