condition in which the bones (bone) of an adult progressively soften because of inadequate mineralization of the bone. (In children the condition is called rickets.) Osteomalacia may occur after several pregnancies or in old age, resulting in increased susceptibility to fractures (fracture). Symptoms include bone pain, weakness, numbness of the extremities, and spasms of the hands or feet.

Depletion of the bone minerals may be caused by lack of dietary vitamin D (or its precursor, ergosterol), inadequate exposure to sunlight (necessary for the formation of vitamin D in the body), impaired function of one of the organs involved in the absorption or metabolism of the bone minerals or vitamin D, frequent ingestion of mineral oil (in which vitamin D dissolves but is not absorbed from the intestines), or abnormalities in the bone mineralization process.

Individuals with osteomalacia frequently have multiple nutrient deficiencies. Treatment includes a well-balanced diet high in protein and calcium and supplemented in moderation with vitamin D concentrates or fish-liver oils.