Vitamin deficiency and vitamin K deficiency. In the medical literature, any of these may also be called by names on the pattern of "hypovitaminosis" or "avitaminosis" + "[letter of vitamin]", for example, hypovitaminosis A, hypovitaminosis C, hypovitaminosis D. Conversely hypervitaminosis is the syndrome of symptoms caused by over-retention of fat-soluble vitamins in the body. Vitamin deficiency A vitamin deficiency can cause a disease or syndrome known as an avitaminosis or hypovitaminosis. This usually refers to a long-term deficiency of a vitamin. When caused by inadequate nutrition it can be classed as a "primary deficiency", and when due to an underlying disorder such
Vitamin B12 deficiency anemia specifically, from Imerslund-Grasbeck Syndrome (IGS), a vitamin B12-deficiency caused by mutations in cubilin the cobalamin receptor. The treatment of PA varies by country and area. Opinions vary over the efficacy of administration (parenteral/oral), the amount and time interval of the doses, or the forms of vitamin B (e.g. cyanocobalamin/hydroxocobalamin). More comprehensive studies are still needed in order to validate the feasibility of a particular therapeutic method for PA in clinical practices. A permanent cure for PA is lacking, although repletion of B should be expected to result in cessation of anemia-related symptoms, a halt in neurological deterioration, and in cases