Vitamin B12 Deficiency and Vitamin B12 Supplements

Vitamin B12 is part of the group of 8 vitamin B family and is known as cobalamin. All B vitamins are essential for the body and they help convert carbohydrates to glucose from which energy is produced. Vitamin B12 works along with B6 and B9 to regulate blood levels of homocysteine – an amino acid. B12 is also needed for production of RNA, DNA and sustaining healthy nerve cells.

Causes of Vitamin B12 deficiency

There are certain groups who are more vulnerable to vitamin B12 deficiency.

Older people are more at risk of vitamin B12 deficiency than younger people are. 10 – 30% of senior citizens suffer from atrophic gastritis that reduces secretion of hydrochloric acid and therefore decreases absorption levels of vitamin B12 by the stomach. Low hydrochloric acid levels in the stomach can cause an increased presence of intestinal bacteria, which use vitamin B12. Since these bacteria use up the vitamin B12, there is less available for the rest of the body’s functions. 

Although those with atrophic gastritis cannot absorb vitamin B12 from foods, they can do so from dietary supplements or from fortified foods. Hence, it is recommended that senior citizens take vitamin B12 supplements and foods enriched with this vitamin. They must also take higher does than what is recommended for those without atrophic gastritis to prevent a sub-clinical deficiency of vitamin B12.

Pernicious anemia is one of the most common causes of vitamin B12 deficiency. The parietal cells in the stomach lining make a protein called intrinsic factor. Vitamin B12 joins with this intrinsic factor and forms a complex that the intestines absorb and use for the body. A person suffering from pernicious anemia does not produce intrinsic factor or very little of it. This prevents absorption of vitamin B12, therefore contributing to the deficiency. 

Gastrointestinal disorders such as Crohn’s disease and celiac disease affect the small intestine and stomach and block their ability to absorb sufficient quantities of vitamin B12 required by the body. If untreated, this deficiency can lead to dementia and megaloblastic anemia. Sometimes parasites present in intestines can cause bacterial overgrowth and a deficiency in B12. 

Gastrointestinal surgery to remove part of the stomach or intestine can prevent the ability of the stomach cells to produce intrinsic factor and hydrochloric acid. Food-bound vitamin B12 does not get absorbed or released efficiently. Surgically removing the distal ileum also causes a vitamin B12 deficiency. Patients undergoing such surgeries must be monitored carefully for all nutrient deficiencies.

Pregnant women and those who are breastfeeding babies are especially vulnerable if they follow a strict vegetarian diet. They have inadequate reserves of vitamin B12, as they do not eat animal products rich in this nutrient. Since vitamin B12 nourishes the fetus and it is found in breast milk, both mother and baby will become deficient. If this deficiency is undetected, babies can develop dangerous and irreversible neurological damage.

Vegetarians :  Vitamin B12 is found only in animal products. Hence, ovo-vegetarians and vegans may suffer from a deficiency. Such people can take fortified breakfast cereals that have a good dietary source of vitamin B12 for vegetarians. 

Other causes:

  • Chronic alcoholics suffer from folate or vitamin B12 deficiency since they do not eat a balanced diet.
  • Drugs such as omeprazole and metformin result in vitamin B12 malabsorption, gastric acids are reduced and food proteins release less amounts of B12 for use by the body.  
  • HIV/AIDS patients and those suffering from eating disorders can have vitamin B12 deficiency.

Symptoms of vitamin B12 deficiency

  • Megaloblastic anemia
  • Fatigue
  • Weaknessvitamin b12 rich foods
  • Loss of appetite
  • Weight loss
  • Constipation
  • Tingling and Numbness in hands and feet
  • Depression
  • Confusion
  • Inability to maintain balance
  • Dementia
  • Soreness in the tongue or around the mouth
  • Poor memory
  • Developmental and movement disorders in infants
  • Chronic pancreatitis

These are general symptoms and can occur due to various other deficiencies. Hence, proper tests are required to identify the cause of the symptoms before treatment is given. 

The doctor will check your symptoms and then run some blood tests to check the red blood cell count. This can reveal levels of vitamin B12 in the body. At the same time, levels of folic acid will also be checked since it works closely with B12 and the right balance needs to be maintained. Once the doctor pinpoints the problem, the proper treatment will be given.

Vitamin B12 supplements

Vitamin B12 supplements are usually available as individual supplements, complex vitamin supplements, multivitamins and supplements that are palatable for children like liquid drops or chewable tablets. These supplements are available as soft gels, intranasal form, oral capsules or tablets and lozenges. Other names for these supplements are cyanocobalamin and cobalamin. 

It has been recommended by the ‘American Dietetic Association’ that ovo-vegetarians and vegans who are pregnant and lactating must take sufficient vitamin B12 supplements so that there is no danger of a deficiency in both mother and baby. 

Precautions while taking Vitamin B12 supplements

It has been suggested that people take a combination of all vitamin B complex supplements together to avoid a possible imbalance of one over the other. Usually folic acid and B12 are taken together to prevent deficiency of either nutrient. Vitamin B12 is normally safe and does not produce any known toxicity. Those on the following medications must check their levels of B12 for it can reduce when interacting with them – chemotherapy and anti-seizure medication, H2 blockers, proton pump inhibitors, bile acid sequestrants and medications taken for diabetes.


Vitamin B12 deficiency while rare can cause nerve damage when it does occur. Along with vitamin B12 levels, folate levels must also be checked. High levels of folic acid masks a deficiency in B12 therefore treating megaloblastic anemia but not correcting the attendant neurological problems. Those who are at risk of a deficiency or who are strict vegetarians must ensure they take fortified foods or vitamin B12 supplements with other vitamins to maintain the optimal balance required for good health.