Vitamin B12 deficiency – why your body needs support now
Do you often feel tired even though you get enough sleep? Then you’re not alone. Many people suffer from vitamin B12 deficiency without knowing it. The tricky thing is that the symptoms are often nonspecific—but your body is sending you signals that you should take seriously.
What causes vitamin B12 deficiency?
A deficiency does not automatically mean that you are eating poorly. Often the problem lies deeper—in the body itself.
Did you know?
The proportion of people with vitamin B12 deficiency is estimated to be around 5–10 percent in young and middle-aged adults, while it rises to around 20–30 percent or more in older people (aged 65 and above). 1,2
If your body cannot absorb vitamin B12 properly
In order for vitamin B12 to be absorbed at all, your body needs what is known as intrinsic factor—a protein that is produced in the stomach. If this is lacking, the vitamin cannot be adequately utilized from food.
Why your body sometimes struggles to absorb vitamin B12:4
- Stomach or intestinal disorders, e.g., gastritis, Crohn’s disease
- Stomach surgeries that alter the points of absorption
- Medications such as gastric acid blockers or metformin
When your needs increase
Sometimes your body simply needs more:
- during pregnancy and breastfeeding5
- during growth phases6
- with high alcohol consumption7
with age
As we age, our bodies produce less stomach acid, which reduces our ability to absorb vitamin B12. This is why deficiency is particularly common in people over the age of 60.1
How to recognize a vitamin B12 deficiency
If you notice several of these symptoms of vitamin B12 deficiency, have your blood values checked.
Did you know?
It is often said that joint pain and weight gain are signs of vitamin B12 deficiency. However, there is no scientific evidence to support this.
A vitamin B12 deficiency can cause fatigue, concentration problems, or nerve damage, but not joint pain or weight gain. These symptoms usually have other causes, such as hormonal changes, metabolic problems, or lack of exercise.
How is vitamin B12 deficiency diagnosed?
Only a blood test can reliably show whether you are affected by vitamin B12 deficiency.
Important values are: 10
- Total vitamin B12
- Holotranscobalamin (Holo-TC) – the active B12
- Methylmalonic acid (MMA) – indicates whether your cells are getting enough B12
Doctors can use these values to determine precisely whether and to what extent a deficiency exists.
What happens if you ignore the deficiency?
If vitamin B12 deficiency remains untreated, it can impair nerve function and blood formation in the long term. This can have the following consequences:8
- permanent nerve damage
- Anemia
- Concentration problems, memory loss, or depressive moods
The good news:
If the deficiency is detected early, your body can recover completely.
The good news:
If the deficiency is detected early, your body can recover completely.
When it is better to see a doctor
Vitamin B12 deficiency often goes unnoticed for a long time—the symptoms are easy to overlook. But your body sends you signals that you should take seriously. A visit to the doctor can quickly clarify the situation—and is the most important step toward feeling completely well again.
Play it safe if you:
- constantly feel tired despite getting enough sleep
- notice tingling or numbness, especially in your hands and feet
- are vegetarian or vegan
- regularly take acid blockers or metformin
- are over 60 years old
Your doctor can determine whether you are affected with a simple blood test—and advise you on the appropriate forms of therapy.
Vibe®—the bonus for vegans and vegetarians*
- Highly concentrated vitamin B12 for your daily needs
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How long does it take to correct a vitamin B12 deficiency?
That depends on why the deficiency arose and how depleted your reserves are. The body stores vitamin B12 in the liver and muscles—it takes some time for the reserves to be replenished.
Typical course:
- Injections: initial effects often noticeable after 1–2 weeks
- tablets or drops: slightly slower, but just as effective with correct intake
- complete recovery: usually after a few weeks to months
Keep at it—your body will thank you with renewed energy and mental clarity.
Frequently asked questions about vitamin B12 deficiency
What are the most common causes of vitamin B12 deficiency?
Absorption disorders in the gastrointestinal tract, certain medications, or increased requirements.
Can a vitamin B12 deficiency cause joint pain?
No, vitamin B12 deficiency does not cause joint pain. Typical symptoms are more likely to include fatigue, concentration problems, or nerve damage. Joint problems usually have other causes, such as hormonal changes or overexertion.
Does vitamin B12 deficiency lead to weight gain?
No, there is no scientific evidence of a link between vitamin B12 deficiency and weight gain. Weight gain is usually related to diet, exercise, or hormonal factors—not vitamin B12 levels.
How quickly do vitamin B12 supplements work?
Depending on the form of intake, between a few days and several weeks – patience pays off.
Can I just take vitamin B12?
Have your levels tested at the doctor’s office beforehand – then you can take targeted and safe action.
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Vibe® 1 mg tablets provide your body with a targeted high dose of vitamin B12 – certified vegan, scientifically proven, and developed in Germany.
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1 Conzade, Romy, u. a. „Prevalence and Predictors of Subclinical Micronutrient Deficiency in German Older Adults: Results from the Population-Based KORA-Age Study“. Nutrients, Bd. 9, Nr. 12, 2017, https://doi.org/10.3390/nu9121276.
2 „Vitamin B12“. Nih.gov, ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/. Zugegriffen 21. Oktober 2025.
3 Al-Awami, Hashim M., u. a. „Physiology, Gastric Intrinsic Factor“. StatPearls, StatPearls Publishing, 2025.
4 Ankar, Alex, und Anil Kumar. „Vitamin B12 Deficiency“. StatPearls, StatPearls Publishing, 2025.
5 Ströhle, Alexander, u. a. „The Revised D-A-CH-Reference Values for the Intake of Vitamin B12 : Prevention of Deficiency and Beyond“. Molecular Nutrition & Food Research, Bd. 63, Nr. 6, 2019, S. e1801178, https://doi.org/10.1002/mnfr.201801178.
6 „Children“. Linus Pauling Institute, 29. April 2014, lpi.oregonstate.edu/mic/life-stages/children.
7 Gibson, A., u. a. „Alcohol Increases Homocysteine and Reduces B Vitamin Concentration in Healthy Male Volunteers–a Randomized, Crossover Intervention Study“. QJM: Monthly Journal of the Association of Physicians, Bd. 101, Nr. 11, 2008, S. 881–887, https://doi.org/10.1093/qjmed/hcn112.
8 N. H. S. „Vitamin B12 or Folate Deficiency Anaemia – Complications“. Nhs.uk, 4. April 2023, www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/complications/. „Health Risks of an Inactive Lifestyle“. Fitness and Exercise, 2017, medlineplus.gov/healthrisksofaninactivelifestyle.html.
10 Hannibal, Luciana, u. a. „Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency“. Frontiers in Molecular Biosciences, Bd. 3, 2016, S. 27, https://doi.org/10.3389/fmolb.2016.00027.
11 „Vitamin B12 Deficiency“. Cleveland Clinic, 27. April 2022, my.clevelandclinic.org/health/diseases/22831-vitamin-b12-deficiency.
12 Badar, Ahmed. „Neuropsychiatric Disorders Associated with Vitamin B12 Deficiency: An Autobiographical Case Report“. Cureus, Bd. 14, Nr. 1, 2022, S. e21476, https://doi.org/10.7759/cureus.21476.
