Condition resulting from inadequate diet or from inability to absorb or metabolize nutrients.
Food intake may be insufficient to supply calorie s or protein (see kwashiorkor ) or deficient in one or more essential vitamin s or minerals. The latter case can lead to specific nutritional deficiency diseases (including beriberi , pellagra , rickets , and scurvy ). Metabolic defects, especially of the digestive system, liver , kidney s, or red blood cells, prevent proper digestion , absorption, and metabolism of nutrients. See also nutrition .