Effect on bones:
Kuftinec concluded bone develops in a manner similar to other soft tissues. First the soft tissue matrix is laid down followed by the formation of the hard tissue components. In animal studies, a high rate of bone growth can readily be demonstrated around the time of weaning when the animal changes from a relatively low protein to a high protein diet which is during the hyperplastic growth phase. Therefore it is the critical period in the development of bone. It is important to point out that growing bone is different to mature bone in its response to the environment. Any nutritional deficiency occurring during the active growth can be disastrous.
Vitamin A defieciency which frequently accompanies protein calorie malnutrition may result in inadequate bone growth patterns with concomitant malalignment and malocclusion of the teeth. An excess of vitamin A during the critical growth period markedly inhibits the neural crest cell development and upsets the normal balance between bone formation and resorption. Increased Vitamin A also causes softening of the skull due to decrease in the calcium deposition.
Calcium, Vitamin D and phosphorus are essential for the formation of bones and teeth. Deficiencies of these nutrients cause retarded jaw , teeth and condyle development.
Deficiency of Vitamin D causes rickets, maxillary dysplasia, succeptibility to muscular traction. Facial sutures close with difficulty leading to openbite, transverse hypodimension and misshapen palate.
Cleft lip and palate
Worlds most common birth defect is the cleft lip and cleft palate (1 in 900 births). A variety of nutrient deprivation or excess as well as terratogenic agents can produce a very high incidence of this congenital anomaly as palatal tissues are very succeptible to environmental changes.
During palatal development a number of macromolecules increase during the critical ctages of palatal fusion like glycoproteins, enzymes, actin and mucopolysaccharides. If these are not supplied in the required amounts due to nutritional deficiency then will lead to the anomaly. Studies suggest that an excess of vitamin A during this phase may lead to cleft palate formation.