Constantly tired despite getting plenty of sleep: What do vitamin B12 and fatigue have in common?
Do you struggle to get out of bed in the morning—and feel tired all day long? Persistent fatigue could be caused by more than just a lack of sleep. Find out what the causes are and what you can do about it here.
Why fatigue isn't always caused by too little sleep
Had a short night? Barely slept? Or have you had a stressful day? Then it’s perfectly normal to feel tired and exhausted. Short-term exhaustion, for example after physical or mental strain, is part of everyday life for many people.
However, if you feel tired all the time—despite getting plenty of sleep and taking enough breaks—this could be a warning sign from your body. Persistently low energy levels may be an indication that your body needs support.
This is often caused by a nutrient deficiency, which noticeably limits your physical and mental performance. Fatigue can occur particularly in connection with a deficiency of the following nutrients:
- iron¹
- vitamin D²
- folic acid³
- vitamin B12⁴
Vitamin B12 deficiency in particular is suspected to cause profound, persistent exhaustion. Many sufferers therefore rely on vitamins to combat fatigue and get their energy metabolism back on track.
Feeling tired all the time? How vitamin B12 and energy are related
Vitamin B12 performs many tasks in the body—below are those that are particularly closely related to your energy levels:
- Normal energy metabolism: In order for your body to obtain energy from food, it must convert fats, carbohydrates, and proteins into usable energy. Vitamin B12 plays a crucial role in these conversion processes—without sufficient B12, your energy metabolism works less effectively.⁵
- Reduction of tiredness and fatigue: When your body has enough vitamin B12, it can provide energy more efficiently. This helps you feel more alert and productive and less prone to fatigue.⁵
- Normal red blood cell formation: Vitamin B12 is necessary for the formation of healthy red blood cells. These transport oxygen to all the cells in your body. A lack of B12 means that less oxygen reaches the cells, which can lead to fatigue, paleness, and concentration problems.⁶
What does fatigue feel like when you have a vitamin B12 deficiency?
Fatigue caused by vitamin B12 deficiency is characterized by its particular intensity: many of those affected experience it as a kind of chronic lack of energy that hardly improves even after a good night’s sleep. This is often accompanied by concentration problems, mood swings, and in some cases even depressive moods.
If the deficiency persists for a longer period of time, further symptoms may occur, such as:
- weakness
- pallor
- tingling in the limbs
- nerve damage
The causes of these symptoms lie in impaired energy production and blood formation, as well as weakened nervous system function.
Did you know?
Vitamin B12 deficiency often develops gradually. The body—especially the liver—can store the vitamin for several years.⁷ This is why the first signs of deficiency often only become apparent at a very late stage: fatigue gradually increases and performance declines—without it being immediately clear why.
Constantly tired: When is it advisable to see a doctor?
Fatigue is part of everyday life—but it shouldn’t be your default state. If you feel exhausted for weeks on end without any apparent cause, such as lack of sleep, it’s time to seek medical advice.
You should be particularly vigilant if the following signs appear:
- significantly reduced ability to concentrate
- constant lack of energy
- pale skin or muscle weakness
- tingling or numbness in the hands and feet
- mood swings or depressive moods
All of these can be signs of vitamin B12 deficiency or other physical causes that are easily treatable—provided they are detected in time.
All of these can be signs of vitamin B12 deficiency or other physical causes that are easily treatable—provided they are detected in time.
Vitamins and other remedies for fatigue: What you can do when you feel exhausted
If a vitamin B12 deficiency is detected, treatment should be tailored to your individual needs—for example, through a targeted diet or, in consultation with your doctor, through appropriate vitamin B12 supplements to combat fatigue.
Once vitamin B12 levels have stabilized, Vibe® 1 mg tablets (equivalent to 1,000 μg) can be used for long-term treatment of anemia caused by vitamin B12 deficiency (pernicious anemia).
For long-term treatment of anemia
Vibe® 1 mg tablets
(contains 1.000 μg)
- high-dose vitamin B12
- certified vegan
- easy intake
But even if you don’t have a medically proven deficiency, there are things you can do to boost your energy levels:
- Keep your diet healthy and balanced.
- Get plenty of sleep.
- Exercise regularly.
- Reduce stress.
Even small changes in your daily routine can make a noticeable difference in helping you feel fitter and more alert again.
Even small changes in your daily routine can make a noticeable difference in helping you feel fitter and more alert again.
Frequently asked questions about constant fatigue despite sufficient sleep
What deficiency is behind constant fatigue?
Constant fatigue can indicate a nutrient deficiency—especially iron, vitamin D, folic acid, or vitamin B12.1, 2, 3, 4
Vitamin B12, for example, is important for energy metabolism, reducing tiredness and fatigue, and the formation of red blood cells.5,6 A blood test by a doctor can clarify possible causes.
What helps combat fatigue caused by vitamin B12 deficiency?
If you have a proven vitamin B12 deficiency, treatment should be carried out in consultation with your doctor. In the case of anemia caused by vitamin B12 deficiency (pernicious anemia) – and after stabilization of the values – the high-dose Vibe® 1 mg tablets (equivalent to 1,000 μg) can be used for long-term treatment, for example. In addition to medication, it is important to ensure a balanced diet, sufficient sleep, and as little stress as possible.
You may also be interested in
Vibe® 1 mg tablets provide your body with a targeted high dose of vitamin B12 – certified vegan, scientifically proven, and developed in Germany.
When your body needs more
Learn how high doses of vitamin B12 work, when they are necessary, and how they can be administered.
Tingling in your hands or feet?
Polyneuropathy involves damage to multiple nerves, which manifests itself in symptoms such as tingling and numbness.
1 Świątczak, Michał, u. a. „Chronic Fatigue Syndrome in Patients with Deteriorated Iron Metabolism“. Diagnostics (Basel, Switzerland), Bd. 12, Nr. 9, 2022, S. 2057, doi:10.3390/diagnostics12092057.
2 Khan, R., u. a. „Frequency of Vitamin d Deficiency in Patients with Fatigue“. Journal of University Medical & Dental College, Bd. 5, Nr. 1, 2014, S. 26–31, jumdc.com/index.php/jumdc/article/view/268.
3 Singh, Jagdish. „Vitamin B9 in dark green vegetables: Deficiency disorders, bio-availability, and fortification issues“. B-Complex Vitamins – Sources, Intakes and Novel Applications, IntechOpen, 2022.
4 Pupić-Bakrač, Ana, u. a. „Extremely severe vitamin B12 deficiency: Case presentation and review of literature“. Medicina Fluminensis, Bd. 55, Nr. 3, 2019, S. 301–310, doi:10.21860/medflum2019_221625.
5 Lee, Mon-Chien, u. a. „A Functional Evaluation of Anti-Fatigue and Exercise Performance Improvement Following Vitamin B Complex Supplementation in Healthy Humans, a Randomized Double-Blind Trial“. International Journal of Medical Sciences, Bd. 20, Nr. 10, 2023, S. 1272–1281, doi:10.7150/ijms.86738.
6 Abdellatif, Karim, und Mohammed Al- Jubory. „Managing Vitamin B12 deficiency: A Comprehensive Guide“. Scholars journal of applied medical sciences, Bd. 11, Nr. 09, 2023, S. 1749–1755, doi:10.36347/sjams.2023.v11i09.026.
7 Temova Rakuša, Žane, u. a. „Vitamin B12 in Foods, Food Supplements, and Medicines-A Review of Its Role and Properties with a Focus on Its Stability“. Molecules (Basel, Switzerland), Bd. 28, Nr. 1, 2022, S. 240, doi:10.3390/molecules28010240.
