A group of diseases caused by the deficiency of one or more vitamins e.g. Beriberi (thiamine deficiency), rickets (Vitamin D deficiency), pellagra (niacin deficiency), pernicious anemia (Vitamin B12), bleeding (vitamin K deficiency) and night blindness (avitaminosis A). Symptoms depend on the type and degree of vitamin deficiency. Lack of various vitamins can affect just about every part of the body including the nervous system. See also Avitaminosis
