calcification

1. 1. Impregnation with calcium or calcium salts, as with calcium carbonate.
   2. Hardening, as of tissue, by such impregnation.
2. A calcified substance or part.
3. An inflexible, unchanging state: calcification of negotiations.

The process whereby calcium salts are deposited in an organic matrix. The condition may be normal, as in bone and tooth formation, or pathologic in nature.

The deposition of calcium salts in tissue. Calcification is important in bone formation.

The deposit of calcium salts in a tissue. The normal absorption of calcium is facilitated by parathyroid hormone and by vitamin D. In poisoning with calcinogenic glycosides and when there are increased amounts of parathyroid hormone in the blood (as in hyperparathyroidism), there is deposition of calcium in the soft tissue. (In hyperparathyroidism secondary to renal disease there is deposition in the alveoli of the lungs, the renal tubules, beneath the parietal pleura, the gastric mucosa, and the arterial walls.) Normally calcium is deposited in the bone matrix to insure stability and strength of the bone. In osteomalacia there is an excess of unmineralized osteoid because the aged well-mineralized bone is replaced by a matrix that is inadequately mineralized.

• dystrophic c. — the deposition of calcium in abnormal tissue without abnormalities of blood calcium.
• metastatic c. — deposition of calcium in tissues as a result of abnormalities of calcium and phosphorus levels in the blood and tissue fluids.
• nutritional c. — calcification in soft tissues as a result of an increased intake of calcium.
• soft tissue c. — see metastatic calcification (above), dystrophic calcification (above).