Amelia Grant

Vitamin B12, also called cobalamin, is an essential water-soluble vitamin that’s involved in the production of red blood cells and DNA, as well as helps maintain the nervous system. Although B12 is contained in many foods like meats, dairy, bread, eggs, and fish, many people, especially older adults, are deficient in it. Some people may also lack this vitamin, as their bodies are unable to absorb it well. However, there are some other surprising causes of vitamin B12 deficiency, such as:

1. Common prescription drugs

Prescription medications like methotrexate (used to treat psoriasis, rheumatoid arthritis, and certain types of cancer), some antibiotics, and certain cholesterol-lowering pills can lead to vitamin B12 deficiency. 

2. Oral contraceptives 

According to a 2013 study published in the journal Nutrients, taking oral contraceptives is one of the most common reasons for vitamin B12 deficiency in women. Hormonal contraception does provoke B12 levels to decrease. 

3. Weight loss surgery 

Though bariatric surgery can be extremely helpful for people with severe obesity, it’s one of the common causes of low levels of vitamin B12. In those who have had weight loss surgery that involves removing part of the stomach, vitamin B12 levels can drop significantly. But these people are usually prescribed a form of vitamin B12 that bypasses the digestive tract and enters straight to the bloodstream. 

4. H.pylori infection 

1. H.pylori are the bacteria that provoke stomach ulcers and can be the culprit of vitamin B12 deficiency. About half of the entire world’s population might have H. pylori. 

5. Diabetes 

According to a study published in the Journal of Diabetes and Metabolic Disorders, people with type 1 and type 2 diabetes have a high risk of developing vitamin B12 deficiency. Taking metformin (a common treatment option for diabetes) can interfere with B12 absorption. 

6. Vegetarian or vegan diet 

Since vitamin B12 is mostly found in animal products, those who follow vegetarian or vegan diets often lack this essential nutrient. Remember that the body can’t produce vitamin B12 so you need to get it from foods. If you’re vegan or vegetarian, consider talking to your healthcare provider about taking vitamin B12 supplements. 

7. Age 

In fact, one in 33 adults over the age of 50 suffer from vitamin B12 deficiency. This is due to the fact that in older adults, production of stomach acid decreases as a normal part of aging. Therefore, doctors might prescribe a supplement to people as they get older. 

8. Pernicious anemia 

Pernicious anemia is an autoimmune disorder in which the immune system mistakenly attacks the healthy cells in the stomach that produce the protein we need to absorb vitamin B12. The National Heart, Lung, and Blood institute claims that without this protein the body isn’t able to move vitamin B12 through the small intestine, where it’s absorbed. 

9. Stress 

Stress can take a toll on any system in your body. It’s also able to trigger vitamin B12 deficiency by exacerbating ulcers and bumping up stomach acid production which is why people need to take antacids that lower the levels of this vitamin in the body. 

10. Gut problems 

People with Crohn's disease and celiac disease often suffer from vitamin B12 as well. In healthy people, vitamin B12 is absorbed through the intestines, but disorders that provoke inflammation and damage the small intestines can negatively affect the ability to absorb this nutrient. 

11. Atrophic gastritis 

Gastritis is a condition that’s characterized by an inflammation of the stomach lining. It’s usually caused by long-term use of pain relievers, bacterial infection, and stress. It’s also one of the reasons for vitamin B12 deficiency.