Osteomalacia is common in celiac disease. Osteomalacia can occur at any age. It children, it is called rickets.  It is a metabolic bone disorder that involves slow loss of minerals from bone tissue throughout the skeleton, stemming from inadequate absorption of vitamin D. As minerals are dissolved from bone tissue to provide for essential functions elsewhere in the body, bones gradually lose their hardness.

Consequently, pronounced softening of the bones characterizes osteomalacia. Soft bones become deformed, especially bones of the arms, legs, spine, thorax and pelvis. The softer bones have a normal amount of collagen, a strong fibrous protein in the bone matrix (osteoid) that gives bone its structure and tensile capacity, but there is not sufficient calcium and phosphate minerals available to properly mineralize or be deposited in the osteoid to give it necessary hardness.