Vitamin B12: Benefits, Rich Foods, Deficiency & Treatment

Vitamin B12

Do you often find yourself feeling fatigued, lethargic, or experiencing tingling sensations? These could be signs of a silent yet crucial nutrient deficiency – vitamin B12.

This critical vitamin, overlooked but indispensable, plays a pivotal role in our well-being.

As we delve into the depths of Vitamin B12, you will discover how it contributes to everything from nerve function to DNA synthesis, making it a cornerstone for overall health.

Let’s begin and uncover the secrets of a nutrient that holds the key to a vibrant and energized life.

What is Vitamin B12?

Vitamin B12, also known as cobalamin, stands as a powerhouse among essential nutrients, playing a crucial role in various bodily functions.

This water-soluble vitamin is integral for nerve tissue health, DNA and red blood cell synthesis. Primarily found in animal products, B12 poses a particular challenge for vegetarians and vegans, necessitating a thoughtful approach to dietary choices.

Deficiency in this critical nutrient may lead to fatigue, anaemia, neurological issues, and potentially severe complications if left unaddressed 1.

While meat, fish, and dairy are traditional sources, fortified foods and supplements provide alternatives for those following plant-based diets.

Vitamin B12 Normal Range

In general, vitamin B12 levels in the blood are often reported in picograms per millilitre (pg/mL) or picomoles per litre (pmol/L). Typically, around 200 to 900 pg/mL is considered normal.

Vitamin B12 Benefits

The health benefits and reasons for maintaining healthy vitamin B12 levels are mentioned below.

Neurological Support

Vitamin B12 is important for optimal neurological function. It is essential for the synthesis of myelin, a protective coating around nerve fibres, promoting nerve signal transmission.

Adequate B12 levels contribute to cognitive health and may help prevent neurological disorders 2.

Red Blood Cell Formation

One of the major functions of vitamin B12 is to assist the formation of red blood cells 3.

It collaborates with folate in DNA synthesis within red blood cell precursors, preventing megaloblastic anaemia and ensuring the proper oxygen-carrying capacity of the blood.

Energy Metabolism

Vitamin B12 is a chief player in the conversion of food into energy. It aids in the metabolism of fats and carbohydrates, contributing to the production of ATP (adenosine triphosphate), the body’s primary energy currency.

Sufficient B12 levels help combat fatigue and promote overall vitality.

DNA Synthesis and Cell Division

Necessary for the synthesis of DNA and proper cell division, vitamin B12 is crucial for the growth and maintenance of tissues. It aids in the replication of genetic material, supporting the body’s ability to repair and regenerate cells.

Heart Health

Vitamin B12 works in concert with other B vitamins to regulate homocysteine levels. High homocysteine increases the risk for cardiovascular diseases. Maintaining adequate B12 levels supports heart health by keeping homocysteine within a healthy range.

Mood Regulation

Studies have linked vitamin B12 deficiency to mood disorders, including depression and anxiety 4.

It is involved in the synthesis of neurotransmitters like serotonin and dopamine, which influence mood regulation.

Eye Health

Vitamin B12 contributes to optic nerve health and may prevent age-related macular degeneration (AMD). Adequate B12 levels support vision and protect against certain eye conditions.

Bone Health

While the direct link between vitamin B12 and bone health is not fully understood, B12 deficiency has been associated with an increased risk of osteoporosis. Maintaining sufficient B12 levels may contribute to overall bone health.

Immune System Support

Vitamin B12 is involved in the production and maturation of immune cells. A well-functioning immune system relies on proper B12 levels to defend against infections and illnesses.

Prenatal Health

Adequate vitamin B12 is crucial during pregnancy for the proper development of the baby’s nervous system.

It helps minimize the occurrence of neural tube defects and supports the overall health of both the mother and the developing foetus 5.

Vitamin B12 Rich Foods

As per ICMR 2020, the daily requirement of vitamin b12 is 2.5mcg for adult men and women. It may go up during pregnancy and lactation.

These are some vitamin B12 foods.

  • Organ meat like liver & kidney
  • Sardine fish
  • Salmon fish
  • Eggs
  • Dairy products like milk, cheese and curd
  • Fortified foods like juices, breakfast cereals and non-dairy milk
  • Chicken
  • Shitake Mushroom
  • Fortified Nutritional Yeast
Image Source: Freepik

Top Reasons for Vitamin B12 Deficiency

Here are some common reasons for vitamin B12 deficiency.

  1. Dietary Insufficiency: Despite being crucial for health, vitamin B12 is naturally found in significant amounts only in animal products. Strict vegetarians and vegans may face challenges in obtaining adequate B12 through their diet, putting them at a higher risk of deficiency.
  2. Malabsorption Issues: Disorders affecting the gastrointestinal tract, such as celiac disease, gastritis, or Crohn’s disease, may impair the body’s ability to absorb vitamin B12 from food, leading to deficiency even with an adequate dietary intake.
  3. Pernicious Anaemia: In this autoimmune condition, the body attacks its intrinsic factor, a protein necessary for B12 absorption. Without intrinsic factors, the absorption of B12 is severely compromised, resulting in deficiency.
  4. Ageing and Reduced Stomach Acid: As individuals age, the production of stomach acid tends to decline. Since stomach acid is essential for releasing B12 from food, older adults may experience reduced absorption, making them more susceptible to deficiency.
  5. Medications: Certain medications, like antagonists used to treat acid reflux and ulcers, can interfere with B12 absorption.
  6. Gastric Bypass Surgery: Individuals with a history of gastric bypass surgery may experience reduced absorption of B12.
  7. Alcoholism: Chronic alcohol consumption can contribute to vitamin B12 deficiency through multiple mechanisms, including poor dietary intake, impaired absorption, and liver dysfunction, which affects the storage of B12.

Vitamin B12 Deficiency Symptoms

Here are a few common signs and symptoms of vitamin B12 deficiency.

  • Megaloblastic Anaemia
  • Fatigue and Weakness
  • Tingling or Numbness in the Hands & Feet
  • Pins & Needles Feeling
  • Difficulty in Concentrating
  • Memory Issues
  • Mood Swings
  • Poor Vision Health
  • Mouth Ulcers
  • Pale Skin
  • Increased Heart Rate or Palpitations
  • Dizziness

Vitamin B12 Deficiency Treatment 

Image Source: Freepik

Vitamin B12 deficiency is common and can be treated using supplementation and dietary modifications.

Diet Changes

Increasing the intake of vitamin B12-rich foods is essential. Foods such as meat, dairy, fish, and eggs are good sources of B12.

For vegetarians or vegan people, fortified foods or B12 supplements may be necessary.

Oral Supplements

Oral supplementation is often prescribed in case of vitamin B12 deficiency. These can be in the form of powder, capsule, tablet, syrup or liquid spray as cyanocobalamin or methylcobalamin. The recommendations may vary based on the severity of the deficiency and the person’s specific needs.

Vitamin B12 Injections

For severe deficiencies or cases, healthcare providers may administer B12 injections. These injections are usually given intramuscularly.


In conclusion, vitamin B12 plays a crucial role in maintaining our nervous system, supporting red blood cell formation, and contributing to overall energy metabolism.

While the body requires only a small amount of this vitamin, its deficiency can lead to various health issues, ranging from fatigue and weakness to more severe neurological complications.

In the journey towards optimal health, understanding the importance of vitamin B12, being mindful of dietary choices, and seeking timely medical attention for any potential deficiency are key steps.

By doing so, individuals can proactively support their well-being and enjoy the numerous benefits that vitamin B12 brings to the body.

What are some vitamin B12 foods for vegetarians?

Vegetarians can consider yogurt, milk, fortified plant-based milk, cheese, nutritional yeast, mushrooms, and fortified cereals to meet their daily vitamin B12 requirement.

What are the benefits of vitamin B12 for hair?

Vitamin B12 is involved in the production of red blood cells, which carry oxygen and nutrients to hair follicles. This oxygen and nutrient supply is essential for promoting hair growth. Adequate levels of vitamin B12 can help prevent hair loss and keep the scalp healthy.

How to increase vitamin B12?

If you’re looking to increase your vitamin B12 levels, it is important to consume a diet rich in vitamin B12 sources. However, if you have dietary restrictions, you may consider including vitamin B12 supplements in your diet after a doctor’s consultation.

Can vitamin B12 deficiency be a sign of cancer?

Vitamin B12 deficiency itself is not typically considered a direct sign of cancer. However, certain conditions associated with cancer or cancer treatments may contribute to B12 deficiency. If you suspect a vitamin B12 deficiency or are experiencing symptoms associated with low B12 levels, it is crucial to consult with a healthcare professional before concluding any health issue.

How long can it take to recover from vitamin B12 deficiency?

The time it takes to recover from vitamin B12 deficiency can vary depending on the severity of the deficiency, the underlying cause, and the chosen treatment method. In cases of severe deficiency, it may take several weeks to months to normalize B12 levels. The choice of treatment can influence the recovery time. B12 supplementation through injections tends to be more rapid compared to oral supplementation.

  1. O’Leary, F., & Samman, S. (2010). Vitamin B12 in health and disease. Nutrients, 2(3), 299–316.[]
  2. Tangney, C., Aggarwal, N. T., Li, H., Wilson, R. S., DeCarli, C., Evans, D. A., & Morris, M. L. (2011). Vitamin B12, cognition, and brain MRI measures: A cross-sectional examination. Neurology, 77(13), 1276–1282.[]
  3. Krzywański, J., Mikulski, T., Pokrywka, A., Młyńczak, M., Krysztofiak, H., Frączek, B., & Ziemba, A. (2020). Vitamin B12 status and optimal range for hemoglobin formation in elite athletes. Nutrients, 12(4), 1038.[]
  4. Syed, E. U., Wasay, M., & Awan, S. (2013). Vitamin B12 supplementation in treating major depressive Disorder: a randomized controlled trial. The Open Neurology Journal, 7(1), 44–48.×01307010044[]
  5. Behere, R. V., Deshmukh, A. S., Otiv, S., Gupte, M. D., & Yajnik, C. S. (2021). Maternal Vitamin B12 status during pregnancy and its association with outcomes of pregnancy and health of the offspring: A Systematic Review and implications for Policy in India. Frontiers in Endocrinology, 12.[]
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