Vitamin B12 Deficiency: Dietary Causes, Symptoms, and Treatment

March 26, 2026

Blogs, Dietetics and Nutrition, Hematology

Vitamin B12 Deficiency: Dietary Causes, Symptoms, and Treatment

Verified By
KIMS-SUNSHINE
Specialist,
26 March, 2026

Vitamin B12 Deficiency_ Dietary Causes Symptoms and Treatment

Vitamin B12 is a crucial water soluble vitamin from the B group, which is necessary for red blood cells to work properly, synthesise DNA and can impact all kinds of physiological functions- physical, neurological and psychological in nature. Vitamin B12 rich foods include products like meat, milk, dairy products and eggs. It is found in fortified foods, cereals and nutritional yeast, among a few other plant based sources. If you are not getting enough B12 from your diet or are not able to absorb this vitamin properly, you may observe several symptoms like neuropathy, fatigue and anemia. Call us today to learn how to get better, as KIMS Sunshine is the best hospital in Hyderabad, for dealing with nutritional deficiencies.

Causes for B12 deficiency-

The main low B12 levels causes include-

Your body is not making enough intrinsic factor- which B12 can bind to.
You have digestive diseases- like Crohn’s disease which can impact how nutrients are absorbed by the gut.
You have had surgery- like a gastric bypass surgery or removal of the gut due to ischemia- both of which can lead to vitamin B12 absorption issues. .
If you suffer from gastritis- where enough hydrochloric acid is not being made.
If you have a rare genetic disorder like an MTFHR deficiency, or if you drink too much alcohol.
Not eating Vitamin B12 rich foods- being vegan can limit your options.

Vitamin B12 Deficiency Symptoms-

These are some symptoms-

Some of the physical symptoms include you feeling really tired, not having an appetite, having ulcers on the tongue or sores in the mouth, pale skin and nausea or diarrhoea respectively. This is due to anemia or nerve damage.
Neurological symptoms include- neuropathy, vision problems, not being able to remember stuff, getting confused among other related symptoms.
You may also feel very irritable, depressed or realise that your behaviour is no longer normal.

If you have severe neuropathy, brain fog, fatigue and related symptoms,
call a specialist at KIMS Sunshine Hospital today!

Diagnosis of B12 deficiency-

Blood tests are normally done to check – a complete blood count (CBC) can help doctors understand how many blood cells you have and if there are any changes in their structure, due to megaloblastic anemia.

Vitamin B12 levels can be checked in serum.

An MMA and homocysteine test can also help diagnose vitamin B12 deficiency.

Treatment for Vitamin B12 Deficiency-

Treatment normally involves the use of B12 supplements and injections. Injections are also possible options. Nasal sprays and nasal gels have recently become available. You can also help this process by eating B12 rich foods.

If the reason for Vitamin B12 deficiency is acute, then you will need treatment till levels get restored. But, if you have a chronic condition which prevents absorption in the long term, you will need to take supplements for life.

Conclusion

Vitamin B12 is a very important water soluble vitamin that is needed for all cells to perform normally- especially blood. Vitamin B12 is easily available in animal derived foods. The body only stores what is necessary, while the rest is excreted. Adults need about 2.4 mg of Vitamin B12 every day while pregnant and breastfeeding women need much more. Vitamin B12 deficiency is very much treatable and preventable too- if you make the right dietary choices and use the right supplements. So, call us today if you face any issues with nutritional deficiencies or related problems.

Frequently Asked Questions

What is vitamin B12 deficiency?

Vitamin B12 Deficiency is a condition where the body lacks sufficient vitamin B12 needed for red blood cell formation, nerve function, and DNA synthesis. It can result from poor dietary intake, absorption problems, or certain medical conditions, leading to anemia and neurological complications if untreated.

What are the symptoms of vitamin B12 deficiency?

Symptoms include fatigue, weakness, pale or yellowish skin, and shortness of breath. Neurological signs such as numbness, tingling in the hands and feet, and difficulty walking may occur. Some individuals experience memory problems, mood changes, or confusion, reflecting the vitamin’s role in maintaining healthy nerve function.

How is vitamin B12 deficiency diagnosed?

Diagnosis involves blood tests that measure vitamin B12 levels, red blood cell count, and related markers such as methylmalonic acid or homocysteine. Doctors may also assess symptoms and medical history to identify underlying causes. Early detection allows timely treatment and helps prevent progression to severe anemia or nerve damage.

Can vitamin B12 deficiency cause nerve problems?

Yes, vitamin B12 deficiency can damage nerves by affecting the protective covering called myelin. This can lead to numbness, tingling, loss of coordination, and balance difficulties. If not treated, nerve damage may become long-lasting, making early diagnosis and appropriate treatment important for preserving neurological function.

How long does it take to recover from B12 deficiency?

Recovery time depends on severity and treatment method. Energy levels may improve within weeks after starting supplementation, while correction of anemia can take a few months. Neurological symptoms may take longer to resolve and may not fully reverse if deficiency has been prolonged, highlighting the importance of early treatment.