Vitamin B12 deficiencies have been mainly related to blood deficiency diseases, such as macrocytosis and pernicious anaemia. Vitamin B12 deficiencies are followed by neurological and psychological disorders, such as a disturbed sense of coordination, loss of memory, abnormal reflexes, weakness, loss of muscle strength, exhaustion, confusion, low self-confidence, incontinence, impaired vision, frequent need to pass water, psychological deviances.
Methylcobalamin is a very effective treatment for B12 deficiencies commonly found in patients suffer from disease or have nutritional deficits (such as ultra low calorie or vegan diets).
Deficiencies can be caused by low intestinal B12 uptake (intestinal disorders), low intrinsic factor (a substance essential for its transport to the blood) in the stomach, deficiency of hydrochloric acid in the gastric juices (increasing with old age), regular use of laxatives or medicines like Losec (for treatment of peptic ulcer), low uptake in the central nervous system (CNS) or excessive B12 degradation. Lack of calcium in the food can also reduce the uptake and so can heavy metals.