Vitamin B12 Deficiency: Causes, Risks, and Prevention Tips

Vitamin B12 is one of the many B vitamins that are essential for healthy brain cells, nervous system function, red blood cells, heart health, and the formation and repair of genetic material – DNA and RNA- in the cells.

Vitamin B12 is also referred to as “cobalamin” and can be found in different forms including cyanocobalamin, hydrocobalamin, and methylcobalamin.

Vitamin B12 contains a central cobalt atom, making it unique and one of the most complex molecular structures in nature, able to support red blood cells and DNA health. It serves to support and activate many enzymes required for cellular processes, and gene regulation.

Multiple factors can lead to vitamin B12 deficiency such as genetic variants, alcohol intake, dietary deficiency, and intake of certain medications such as oral contraceptives and metformin which is prescribed for the treatment of high blood sugar and diabetes.

Vitamin B12 absorption can be affected by genetics, gastrointestinal disorders, infections, availability of the” intrinsic factor” (a protein produced in the stomach that helps the body absorb vitamin B12), and bacterial overgrowth such as H. Pylori.

Genes play a role in the metabolism of vitamin B12 including FUT2 which codes for an enzyme called fucosyltransferase.

This gene variant affects susceptibility to bacterial and viral infections in the gut which compormise vitamin B12 absorption. Genes that affect the transport of vitamin B12 such as transcobalamin (TCN2) may interfere with the cellular availability of vitamin B12.

Vitamin B12 participates in reactions that impact carbon metabolism in the cells important for DNA repair, energy production, and toxin removal. Gene variants including MTR and MTRR can be associated with an increased demand for vitamin B12.

Symptoms of vitamin B12 deficiency include fatigue, anemia, memory trouble, numbness or tingling in hands and feet, anxiety, and depression.

Deficiency tests include blood tests to measure vitamin B12 plasma levels, increased levels of homocysteine, or elevated methylmalonic acid (MMA).

Red blood cell tests associated with vitamin B12 deficiency are increased (MCV) mean corpuscular volume (MCV), and increased red blood cell distribution width (RDW).

People who are at higher risk for vitamin B12 deficiency include:

·       Elderly patients older than 60 years as they may have poorer absorption.

·       Having gastrointestinal disorders such as celiac or Crohn’s disease.

·       Having had gastric surgery as it may impact absorption.

·       Having Sjogren’s Syndrome- an autoimmune disease that affects absorption of vitamin B12.

·       Vegans and vegetarians due to dietary deficiencies.

·       Taking medication that affects B12 levels such as metformin, proton pump inhibitors, and oral birth control pills.

·       Excessive alcohol intake.

To prevent vitamin B12 deficiency ensure the regular intake of red meat, fish, poultry egg, or dairy products which are rich sources of vitamin B12.  Dietary supplements can be taken to prevent or treat deficiencies. It is important to be aware that high levels of vitamin B12 can be harmful. Supplemental dosages should not exceed 400mcg without the supervision of a medical advisor.