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 D deficiency the metabolism of vitamin D, causing a deficiency. Some types of liver diseases and kidney diseases can decrease vitamin D production leading to a deficiency. The liver is required to transform vitamin D into 25-hydroxyvitamin D. This is an inactive metabolite of vitamin D but is a necessary precursor (building block) to create the active form of vitamin D. In liver disease, the 25-hydroxyvitamin D may not be formed, leading to a vitamin D deficiency. The kidneys are responsible for converting 25-hydroxyvitamin D to 1,25-hydroxyvitamin D. This is the active form of vitamin D in the body. Kidney disease often