What are the health benefits of Vitamin B12?
Vitamin B12 is an essential vitamin with many scientifically proven health benefits.
It plays a central role in supporting the nervous system and promotes cardiovascular health by lowering homocysteine levels. Additionally, it is important for the production of red blood cells, supports the immune system, and aids in energy metabolism, contributing to higher energy levels. Vitamin B12 is also vital for mental health and is associated with the prevention of birth defects. Furthermore, studies show that Vitamin B12 influences bone health as well as the health of hair, skin, and nails. This article explains what Vitamin B12 is, why it is so important for our health, and how much of it we should consume. It also covers how to detect a deficiency and who is particularly at risk.
Table of Contents
- What should I know about Vitamin B12?
- Health benefits of Vitamin B12
- How much Vitamin B12 do I need per day?
- How do I recognize a Vitamin B12 deficiency?
- Risk groups for Vitamin B12 deficiency
- Summary
What should I know about Vitamin B12?
Vitamin B12, also known as cobalamin, plays a crucial role in many essential bodily functions. This vitamin is particularly notable for being water-soluble while also being storable. Unlike many other water-soluble vitamins, Vitamin B12 can be stored in the liver for a long time—often several years. The risk of overdosing on Vitamin B12 is relatively low, as excess amounts are efficiently excreted via the kidneys and urine (Harvard T.H. Chan, 2023).
The human body cannot produce Vitamin B12 on its own, so it must be obtained through food. Naturally, Vitamin B12 is primarily found in animal-based products. Meat, fish, and seafood are especially rich sources of this vitamin. Eggs and dairy products such as milk, cheese, and yogurt also contain valuable amounts of Vitamin B12. Additionally, Vitamin B12 can be found in fortified foods (foods that have been enhanced with specific vitamins and nutrients), such as certain cereals, breads, and nutritional yeast (Cleveland Clinic, 2024).
Health benefits of Vitamin B12
Vitamin B12 offers numerous health benefits that are well documented by scientific studies. Here are some of the most important:
1. Supports the nervous system and protects against neurological diseases like Alzheimer’s
Vitamin B12 plays an essential role in maintaining the health of the nervous system. A deficiency in this vital micronutrient—which is crucial for neurological structures in children, adolescents, and the elderly—is primarily caused by insufficient dietary intake. Deficiency can lead to neurological symptoms ranging from numbness and memory problems to irritability and developmental delays (NHS, 2023). For example, a lack of B12 can delay the formation of the protective sheath around nerve fibers or cause its breakdown. This is problematic because the sheath is critical for the rapid transmission of nerve signals (Nawaz, A. et al. 2020). Furthermore, studies have shown that a Vitamin B12 deficiency is linked to neurodegenerative diseases such as Alzheimer’s, although the exact mechanisms still require further research (Lauer, A. et al., 2022).
2. Promotes cardiovascular health by lowering homocysteine levels
Homocysteine is an amino acid that can be detected in the blood. Under normal conditions, its concentration is low, but elevated levels are associated with conditions such as heart disease and stroke. Vitamin B12, along with Vitamin B6 and folate, helps break down homocysteine into other chemical substances the body needs (Harvard Health, 2014; Cleveland Clinic, 2021). Therefore, Vitamin B12 plays a key role in regulating homocysteine levels and can help reduce the risk of cardiovascular disease and stroke.
3. Supports red blood cell production, strengthens the immune system, and boosts energy levels
Vitamin B12 is essential for the production of red blood cells, which are responsible for transporting oxygen throughout the body (NHI, 2022). A Vitamin B12 deficiency can lead to anemia, a condition in which the body does not produce enough healthy red blood cells. This can cause a decrease in energy, resulting in fatigue and weakness (Gersten, T., 2022). Studies have also shown that Vitamin B12 plays an important role in regulating immune responses. Insufficient levels of folate and B12 can impair nucleic acid production and protein synthesis, hinder immune cell activity, and disrupt metabolic processes (Batista, K. S. et al., 2022; Mikkelsen, K. et al., 2022).
4. Improves mental health
There is evidence that Vitamin B12 may have a positive impact on mental health. Vitamin B12 and other B vitamins are involved in the production of brain chemicals that influence mood and cognitive function (Mayo Clinic, 2018). A deficiency in B12 may be linked to mood swings or depression (Cleveland Clinic, 2024). Studies suggest that early Vitamin B12 supplementation can delay the onset of depressive symptoms and enhance the effectiveness of antidepressants (Sangle, P. et al., 2020). However, the precise relationship between B12 and mental health requires further investigation.
5. Contributes to the prevention of birth defects
Vitamin B12 plays a crucial role in the healthy development of the fetus, especially during early pregnancy. Studies show that a deficiency in this important vitamin can significantly increase the risk of serious birth defects such as neural tube defects (spina bifida, anencephaly, encephalocele) (Molloy, A. M. et al., 2009). The neural tube is a narrow channel that later forms the brain and spinal cord. Additionally, a study of over 11,200 cases found that Vitamin B12 deficiency is associated with low birth weight and that there is a linear relationship between low B12 levels and increased risk of preterm birth (Rogne, T. et al., 2017).
6. Influences bone health and may affect osteoporosis risk
Studies show that people who avoid animal products experience more frequent bone fractures than those who follow other diets. One reason could be the widespread Vitamin B12 deficiency among vegans. A lack of B12 can weaken bones in various ways—for example, by reducing the number of bone-building cells and increasing bone-resorbing cells. Additionally, B12 deficiency may impair blood flow to bone tissue and hinder collagen cross-linking, which is essential for bone stability (Pawlak R., 2021). However, the use of Vitamin B12 as a marker for fracture risk is not yet fully understood and requires more scientific study.
7. Affects the health of hair, skin, and nails
Studies show that changes in Vitamin B12 levels can lead to alterations in skin, hair, and nails. Common skin-related symptoms of deficiency include pigmentation changes, vitiligo, mouth ulcers, dermatitis, and acne. Changes in hair and nail condition, as well as inflammation in the oral mucosa, may also be associated with B12 deficiency (Brescoll, J. et al., 2015). The exact role of micronutrients such as vitamins in maintaining the health of hair, skin, and nails is not yet fully understood, but future research is expected to provide valuable insights.
How much Vitamin B12 do I need per day?
The recommended daily intake of Vitamin B12 varies depending on age, gender, and life circumstances. The following table provides general guidelines for different age groups:
| Age | Men | Women | Pregnant Women |
|---|---|---|---|
| Birth – 6 months | 0.4 mcg | 0.4 mcg | – |
| 7–12 months | 0.5 mcg | 0.5 mcg | – |
| 1–3 years | 0.9 mcg | 0.9 mcg | – |
| 4–8 years | 1.2 mcg | 1.2 mcg | – |
| 9–13 years | 1.8 mcg | 1.8 mcg | – |
| 14–18 years | 2.4 mcg | 2.4 mcg | 2.6 mcg |
| 19+ years | 2.4 mcg | 2.4 mcg | 2.6 mcg |
Source: NHI, 2024
Please note that these recommendations apply to healthy adults and may vary based on individual needs. People with specific medical conditions or lifestyle factors may require different amounts.
How do I recognize a Vitamin B12 deficiency?
A deficiency in Vitamin B12 can lead to a range of symptoms that may seriously impact health. It is important to recognize these symptoms early and consult a doctor if a deficiency is suspected, so that any potential health issues can be treated promptly.
Common symptoms of a Vitamin B12 deficiency include:
- Unusual sensations, numbness, or tingling in the hands, legs, or feet
- Difficulty walking (staggering, balance problems)
- Vision problems
- Mouth or tongue sores
- Trouble thinking (cognitive difficulties) or memory loss
- Fatigue and weakness
- Nausea, vomiting, or diarrhea
- Yellowish skin
- Mood or behavior changes, depression, irritability
- Loss of appetite, weight loss
Sources: Cleveland Clinic, 2024, Harvard Health, 2022
Do you often feel tired, have you noticed any of the symptoms above, or do you simply want to monitor your overall health?
With Homed-IQ’s blood tests, you receive accurate information about whether your levels are within a healthy range—or whether it may be time to take steps to improve your health. The Active Vitamin B12 Blood Test (Holo-TC) allows you to conveniently test your vitamin status at home without having to schedule a doctor’s appointment. Simply collect a blood sample at home, mail it to our ISO-certified laboratory, and receive your results online in a clear and official lab report.
Risk groups for Vitamin B12 deficiency
A deficiency in Vitamin B12 can be problematic because the human body cannot produce this vitamin on its own—it must be obtained through diet or supplements. Certain groups are particularly vulnerable to deficiency, as they may have difficulty absorbing enough Vitamin B12. These include:
| Group | Description of increased Vitamin B12 deficiency risk |
|---|---|
| Older adults | People over the age of 75 have a higher risk of developing a B12 deficiency, as their bodies may no longer absorb Vitamin B12 efficiently. |
| People with gastrointestinal conditions | Conditions affecting the gastrointestinal tract, such as celiac disease or Crohn’s disease, can interfere with Vitamin B12 absorption. |
| Vegetarians and vegans (and their infants) | Plant-based foods typically do not contain natural sources of Vitamin B12, so vegetarians and especially vegans must monitor their levels carefully. Infants of mothers who avoid animal products also have limited B12 stores. |
| People taking certain medications | Certain medications can reduce Vitamin B12 levels. These include metformin (used for diabetes), proton pump inhibitors (for acid reflux and ulcers), H2 blockers (for reducing stomach acid), and oral contraceptives (birth control pills). If you take any of these medications, consult your doctor about how they might affect your B12 levels. |
Sources: NHI, 2024, Harvard Health, 2022, Cleveland Clinic, 2024
Summary
Vitamin B12 is an essential vitamin that supports the nervous system, promotes cardiovascular health, stimulates red blood cell production, strengthens the immune system, and improves energy metabolism. It also contributes to mental well-being, helps prevent birth defects, and has a positive effect on the health of bones, hair, skin, and nails. Although Vitamin B12 can be stored in the body, it must be obtained through diet. A deficiency can lead to health issues, and those at higher risk—such as vegetarians and vegans—should regularly monitor their Vitamin B12 levels to maintain optimal health.
