Vitamin B12 Deficiency and Cancer Connection
Know the connection between vitamin B12 and cancer. Why B12 is required for the body, how to manage and prevent cancer by consuming B12 and more.
Written by Dr. D Bhanu Prakash
Reviewed by Dr. Shaik Abdul Kalam MD (Physician)
Last updated on 31st Jul, 2025
Introduction
Vitamin B12 is an essential nutrient that plays a crucial role in keeping our bodies healthy. It helps in the formation of red blood cells, supports nerve function, and aids in DNA synthesis. However, a deficiency in this vitamin can lead to serious health problems, including anaemia, fatigue, and even neurological issues.
Recently, research has explored a possible link between Vitamin B12 deficiency and cancer. While the connection is still being studied, understanding how low B12 levels may impact cancer risk—or how cancer treatments can affect B12 absorption—is important for patients and caregivers.
In this article, we’ll explore:
The role of Vitamin B12 in the body
Symptoms of Vitamin B12 deficiency
How may deficiency relate to cancer?
Ways to manage and prevent deficiency
What is Vitamin B12, and why is it Important?
Vitamin B12 (also called cobalamin) is a water-soluble vitamin found in animal-based foods like meat, fish, eggs, and dairy. It is crucial for:
Red blood cell production – Prevents anaemia (low red blood cell count).
Nerve health – Protects the nervous system from damage.
DNA synthesis – Helps in cell growth and repair.
Since our bodies cannot produce Vitamin B12, we must get it from food or supplements. Some people, especially vegetarians, older adults, or those with digestive disorders, may struggle to absorb enough B12, leading to deficiency.
Symptoms of Vitamin B12 Deficiency
A deficiency can develop slowly, and symptoms may be mild at first. Common signs include:
Fatigue and weakness (due to anaemia)
Pale or yellowish skin
Tingling or numbness in hands and feet (nerve damage)
Memory problems or confusion
Mood changes (depression, irritability)
Balance issues
Sore tongue or mouth ulcers
If left untreated, long-term deficiency can lead to severe nerve damage and increased risk of certain health conditions, including potential links to cancer.
Consult Top Nutritionists
Can Vitamin B12 Deficiency Increase Cancer Risk?
Research on the connection between Vitamin B12 deficiency and cancer is still evolving. Some studies suggest:
1. Possible Link to Certain Cancers
Stomach and Colon Cancer – Low B12 levels may be linked to chronic inflammation, which can increase cancer risk.
Leukaemia and Lymphoma – Some blood cancers may affect B12 metabolism, leading to deficiency.
However, more research is needed to confirm whether deficiency directly causes cancer or if it is a side effect of cancer-related changes in the body.
2. Cancer Treatments and B12 Deficiency
Certain cancer treatments, such as chemotherapy or radiation, can interfere with nutrient absorption, leading to deficiencies. Patients undergoing these treatments may need B12 supplements to maintain healthy levels.
3. High B12 Levels and Cancer Risk
Interestingly, very high B12 levels (often due to supplements or injections) have also been studied for their possible link to certain cancers. However, this does not mean B12 causes cancer; rather, it may indicate an underlying condition affecting B12 metabolism.
How to Manage and Prevent Vitamin B12 Deficiency
If you suspect a deficiency, consult a doctor for a blood test. Treatment options include:
1. Dietary Changes
Eat more animal-based foods (meat, fish, eggs, dairy).
For vegetarians/vegans: fortified cereals, plant-based milk, or B12 supplements.
2. Supplements
Oral B12 tablets – Effective for mild deficiencies.
Injections – Needed for severe deficiency or absorption issues.
3. Regular Monitoring
If you have a history of cancer or digestive disorders, regular B12 checks are important.
When to See a Doctor?
If you experience:
Persistent fatigue, dizziness, or weakness
Numbness or tingling in hands/feet
Unexplained weight loss or digestive issues
It’s best to get tested. Early detection can prevent complications.
Final Thoughts
While Vitamin B12 deficiency does not necessarily cause cancer, maintaining healthy levels is crucial for overall well-being. If you have symptoms or risk factors, speak to a healthcare provider for personalised advice.
Consult Top Nutritionists
Consult Top Nutritionists
Dr. Bhukya Pavan Kalyan
General Physician
5 Years • MBBS DNB Paediatrics
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dr. Ramalinga Reddy
General Physician
5 Years • MBBS MD General medicine
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dt. Ila Sharma
Clinical Nutritionist
18 Years • Master in food & Nutrition
Gurugram
VIPUL GREENS - SOCIETY CLINIC, Gurugram
Dr Sumanth R
General Physician
2 Years • MBBS
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Ms. Lakshmi Tejasvi
Clinical Nutritionist
14 Years • M.Sc - Clinical Nutrition
Hyderabad
Vibgyor Nutri, Hyderabad
Consult Top Nutritionists
Dr. Bhukya Pavan Kalyan
General Physician
5 Years • MBBS DNB Paediatrics
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dr. Ramalinga Reddy
General Physician
5 Years • MBBS MD General medicine
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Dt. Ila Sharma
Clinical Nutritionist
18 Years • Master in food & Nutrition
Gurugram
VIPUL GREENS - SOCIETY CLINIC, Gurugram
Dr Sumanth R
General Physician
2 Years • MBBS
Bengaluru
PRESTIGE SHANTHINIKETAN - SOCIETY CLINIC, Bengaluru
Ms. Lakshmi Tejasvi
Clinical Nutritionist
14 Years • M.Sc - Clinical Nutrition
Hyderabad
Vibgyor Nutri, Hyderabad
