Vitamin B12 Deficiency; Symptoms, Prevention, and Treatment

Updated on 12 October 2022

Vitamin B12 is one of the important ingredients required by our body. It helps in making DNA and Red Blood Cells in the body. It is interesting to note that our body doesn’t make Vitamin B12. We have to get it from animal foods and supplements. This should be done on a regular basis. Vitamin B12 is stored in the liver for five years and eventually becomes deficient because of the reduced intake in our regular diets. This article covers the common signs and symptoms of Vitamin B12 deficiency along with treatments and other key pointers.

How Much Vitamin B12 is Required by the Body? 

The answer to this question depends upon several factors like age, medical conditions, eating habits, current intake of medications, etc. Here is an average recommendation of the amounts by age. Have a look!



Vitamin B12 Amounts (in micrograms/mcg)


Up to the age of 6 months



7-12 months



4-8 years



9-13 years



14-18 years



18+ years


Follow up with this table to know the appropriate amount of B12 required by the body. Now, you must be thinking about what the foods are that one must eat in order to have an ample amount. So, let us have a look at it.

Foods Rich in Vitamin B12

As told earlier, Vitamin B12 can be found in animal foods. This nutrient can be extracted naturally and from items that have been fortified with it. 

The animal sources include Dairy products, Eggs, Fish, Meat, and Poultry. One can also have supplements or shots if the foods aren’t sufficient enough.

Signs of Vitamin B12 Deficiency 

It is interesting to note that with age, it becomes harder for the body to absorb this Vitamin B12. The deficiency of this vitamin can also happen if one has had weight loss surgery or other operation, wherein some part of the stomach was removed in case of drinking heavily. 

Have a look at some signs of Vitamin B12 deficiency. 

  • One might develop Atrophic Gastritis, wherein the stomach lining has thinned. 
  • Development of Pernicious Anaemia that makes it hard for the body to absorb Vitamin B12. 
  • Development of conditions that affect the small intestine. The conditions include bacterial growth, celiac disease, parasitic infection, Crohn’s disease, etc. 
  • Heavily drinking makes it challenging for the body to absorb nutrients, thereby preventing you from eating enough calories. 
  • Immune system disorders like lupus. 
  • If you are taking several medications, then it might affect the absorption of B12. 

Vitamin B12 deficiency can also be caused by following a strict vegan diet or if you are a vegetarian. Egg and dairy products are necessary to have an ample amount of Vitamin B12. Thus, it is important to have some fortified foods or add supplements to your diet to meet the everyday need for Vitamin B12 as good foods for good health can significantly impact your body.

After signs, let us now discuss the symptoms of Vitamin B12 deficiency.

Symptoms of Vitamin B12 Deficiency 

Vitamin B12 deficiency means that a person is anaemic. A mild deficiency doesn’t cause any symptoms. But if the symptoms are not treated, then it might lead to the following vitamin B12 deficiency symptoms. Have a look! 

  • Weakness
  • Tiredness
  • Lightheadedness
  • Heart palpitations
  • Pale skin
  • Smoothness on the tongue
  • Constipation
  • Reduced appetite 
  • Gas in the body 
  • Diarrhoea 
  • Muscle weakness
  • Numbness
  • Depression
  • Behavioural changes 
  • Loss of vision 

To overcome these signs and symptoms, it is essential to get treated. There are numerous ways of treating the deficiency. Have a look at how Vitamin B12 deficiency can be easily treated.

Treatment of Vitamin B12 Deficiency 

If you have trouble absorbing Vitamin B12, then you need shots and supplements of the B12 vitamin. One can continue taking these shots and supplements until he/she feels that there has been an ample amount of vitamins in the body. 

If you don’t intake animal foods, then you can include Vitamin B12 fortified grains, injections, and supplements to cover up for the deficiency that you have. 

Older people who suffer from B12 deficiency must take multivitamin supplements including B12 as well. 

For most people, taking such supplements resolves the problem. But if you have any nerve damage due to the deficiency, then the damage could be permanent and cannot be treated with supplements or injections. There are some ways with which one can easily prevent vitamin B12 deficiency treatments.

So, let us now discuss it.

Prevention of Vitamin B12 deficiency 

Most people can easily prevent Vitamin B12 deficiency by consuming foods and drinks enriched with Vitamin B12. Here are some key points that might help you. 

  • Eat red meat, milk, fish, etc., that contain Vitamin B12. 
  • Having fortified foods that contain vitamins and nutrients. Fortified foods include breakfast cereals, nutrients, plant milk, bread, etc. Be sure to check the nutritional value.
  • Having Multivitamins. 
  • Avoiding alcohol can also cover up the B12 deficiency. Alcohol abuse damages your digestive system, thereby making it difficult for the body to absorb Vitamin B12. 
  • If you have Crohn’s disease, then be sure to follow the instructions told by the doctor regarding B12.

How is vitamin B12 deficiency diagnosed?

Vitamin B12 deficiency is diagnosed through a combination of clinical assessment, medical history, physical examination, and laboratory tests. Here's an overview of the process involved in diagnosing vitamin B12 deficiency:

  • Medical History and Symptoms: The healthcare provider will begin by conducting a thorough medical history interview, discussing any symptoms and risk factors associated with vitamin B12 deficiency. Common symptoms include fatigue, weakness, pale skin, shortness of breath, tingling or numbness in the hands and feet, difficulty in maintaining balance, and cognitive changes.

  • Physical Examination: A physical examination may be performed to assess signs related to vitamin B12 deficiency. These can include pale skin, glossitis (inflamed tongue), jaundice (yellowing of the skin or eyes), and neurological abnormalities.
  • Blood Tests:

a. Serum Vitamin B12 Levels: A blood test is typically conducted to measure the levels of vitamin B12 in the bloodstream. Low levels indicate potential deficiency.

b. Complete Blood Count (CBC): A CBC test helps assess red blood cell count, size, and morphology. Vitamin B12 deficiency often leads to anemia, and the CBC can reveal abnormal red blood cell characteristics.

c. Homocysteine and Methylmalonic Acid (MMA) Levels: Elevated levels of homocysteine and MMA in the blood can indicate vitamin B12 deficiency. These substances accumulate when B12 is insufficient, leading to potential nerve damage.

  • Imaging and Further Testing: In certain situations, additional tests such as bone marrow examination or imaging studies (e.g., MRI) may be required to assess for underlying conditions or causes of B12 deficiency.

So, this is all the information regarding Vitamin B12 deficiency. The deficiency can show mild as well as severe symptoms. If not treated on time, it can lead to certain abnormalities in the body. Thus, if you have a vitamin B12 deficiency, then it is best to take care of your system and ask your doctor for shots, supplements, etc., to cover up for the deficiency. Please consult your dietician from the best nutrition hospital in India before choosing a diet.

Ms. Vidhya Sri

Sr. Clinical Consultant Dietician

CARE Hospitals, HITEC City





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