What Causes Vitamin B Deficiencies?

Vitamin B is a group of nine water-soluble vitamins that play an important role in the functioning of various organ systems, including the digestive, circulatory and immune systems, and reduce risk of pancreatic cancer. Deficiency of the B vitamins can lead to a variety of conditions, ranging from nervous system disorders such as beriberi due to vitamin B-1 deficiency and skin disorders due to B-2 and B-5 deficiencies to severe anemia and memory loss due to B-9 and B-12 deficiencies. Several factors can contribute to deficiencies of B vitamins.

Diet

Whole grains, such as wheat and oats, and fish, meat, eggs, dairy products and green leafy vegetables are major sources of various types of vitamin B. Certain people, such as vegans, the elderly and chronic alcoholics, are at a higher risk of developing vitamin B deficiencies due to poor diet. Consumption of overcooked foods and processed foods, which are heated to a very high temperature to achieve long shelf life, may lead to vitamin B deficiencies because heat destroys vitamins present in the food.

Malabsorption

Malabsorption or reduced absorption of vitamin B can cause deficiencies even in individuals who eat a balanced diet. Certain autoimmune disorders such as pernicious anemia affect cells in the digestive tract and prevent the absorption of vitamin B, especially vitamin B-12. A March 2003 article in "American Family Physician" says antibodies are produced against the gastric parietal cells, and the destruction of these cells limits the absorption of vitamin B-12 by the body. Stress is another factor that effects the digestive system and may cause malabsorption of B vitamins.

Drugs

Antibiotics such as tetracycline and cephalosporins may interfere with the absorption of B vitamins, especially B-6 and B112. Antibiotics also eradicate healthy, resident bacteria present in the intestines that have the ability to produce some B vitamins. The University of Maryland Medical Center states long-term use of antibiotics can deplete the levels of B vitamins such as B-2, B-9 and B-12. Tricyclic antidepressants and antipsychotic medications called phenothiazines may reduce levels of B-2 in the body.

The University of Maryland Medical Center also states certain heart medications such as digoxin may reduce the ability of heart cells to absorb and use vitamin B-1.