Vitamin B12 deficiency

First appeared in the Norwalk Patch:

“Microbes maketh man”, the provocative byline on the cover of a 2012 (The) Economist issue, refers to the trillions of microbes (human microbiome) residing on and in our bodies and that contribute to our health and wellness. An infographic from the American Academy of Microbiology illustrates the point that “the microbiome helps us extract energy and nutrients from the food we eat, and crowds out or inhibits pathogens.” One of the nutrients that the body needs is Vitamin B12 ─ a class of chemically related cobalt-containing compounds produced by microbes and not found in plants. The physiological forms of B12 are important for growth and replication of all body cells and the functioning of the nervous system. Disruption of the microbiome can trigger a host of ailments, including diseases possibly caused or exacerbated by B12 malabsorption/deficiency.

While the details are still under investigation, it may be that microbes (at least in some cases) regulate the activities of human cells. Abnormal signaling as a result of a disturbed microbiome is associated with different illnesses, including inflammatory bowel disease, Clostridium difficile infections, obesity, diabetes, and pernicious anemia. The underlying cause of clinical symptoms such as neurological problems and gastrointestinal disturbances associated with pernicious anemia is a reduction in erythrocytes (red blood cells) or the oxygen-containing substance, hemoglobin. Impaired B12 uptake (due to the lack of intrinsic factor in the gastric mucosa) contributes to immature red blood cells or megaloblasts characteristic of the illness. Decreased levels of white blood cells (leukopenia) and platelets (thrombocytopenia) are also observed in the blood.

The adult form of pernicious anemia has typically been associated with people of Northern European descent. The incidence of pernicious anemia is also elevated in patients with other immune ailments, including Graves’ disease, myxedema (historically used to describe severe forms of hypothyroidism; also used to describe skin changes that can occur in hypothyroidism and some forms of hyperthyroidism), and thyroiditis. Moreover, an estimated 50% of the world’s population is infected with another etiologic agent, Helicobacter pylori. Infection with this bacterium increases with age and could contribute to one of the downstream risks associated with untreated pernicious anemia i.e., gastric cancers. Under B-vitamin-rich conditions, B12 (as well as B6 and B9) may help lower homocysteine levels. Conversely, elevated plasma homocysteine has been implicated as an important and independent risk factor for coronary artery disease and associated complications. Thus, B12 insufficiency/deficiency may be far more widespread and be a nutritional risk factor for a variety of chronic maladies affecting a graying global population.

Thanks to Nobel Laureate, George Richards Minot’s (working with William Murphy and George Whipple), seminal discovery of an effective liver-based treatment (liver is high in B12) in 1934, a once-fatal disease can now be managed with timely intervention. Treatment these days consists of intramuscular B12 injections or oral medications. According to the US Centers for Disease Control and Prevention, “once treated for a Vitamin B12 deficiency due to pernicious anemia or other irreversible severe problems with absorption, patients need to continue some form of cobalamin therapy for life.”