- and why is the problem so common?
Lack of vitamin B12 can cause pernicious anemia, which WHO considers a global threat. Vitamin B12 is primarily known for its role in red blood cell formation, whereas its role in the brain and nervous system is often overlooked. A vitamin B12 deficiency can easily lead to disabling damage if it goes unnoticed. Pernicious anemia is an autoimmune disease that prevents people from absorbing vitamin B12 from food. The condition is potentially life-threatening but is difficult to diagnose and many people go untreated, according to Associate Professor Heidi Seage, who is affiliated with the Pernicious Anaemia Society. A worsening factor is the climate debate that has inspired an increasing number of people to turn to vegetarianism and veganism. Plant-based diets are known to cause vitamin B12 deficiency, and the problem is insidious and therefore not easy to detect. The use of diabetes medication (such as metformin) can also deplete the body’s levels of vitamin B12