Howe A M, Webster W S
Department of Anatomy, University of Sydney.
Aust Dent J. 1994 Apr;39(2):88-92. doi: 10.1111/j.1834-7819.1994.tb01379.x.
The normal vitamin K status of the human embryo appears to be close to deficiency. Maternal dietary deficiency or use of a number of therapeutic drugs during pregnancy, may result in frank vitamin K deficiency in the embryo. First trimester deficiency results in maxillonasal hypoplasia in the neonate with subsequent facial and orthodontic implications. A rat model of the vitamin K deficiency embryopathy shows that the facial dysmorphology is preceded by uncontrolled calcification in the normally uncalcified nasal septal cartilage, and decreased longitudinal growth of the cartilage, resulting in maxillonasal hypoplasia. The developing septal cartilage is normally rich in the vitamin K-dependent protein matrix gla protein (MGP). It is proposed that functional MGP is necessary to maintain growing cartilage in a non-calcified state. Developing teeth contain both MGP and a second vitamin K-dependent protein, bone gla protein (BGP). It has been postulated that these proteins have a functional role in tooth mineralization. As yet this function has not been established and abnormalities in tooth formation have not been observed under conditions where BGP and MGP should be formed in a non-functional form.
人类胚胎的正常维生素K状态似乎接近于缺乏。孕期母亲饮食缺乏或使用多种治疗药物，可能导致胚胎出现明显的维生素K缺乏。孕早期缺乏会导致新生儿上颌鼻发育不全，继而产生面部和正畸方面的问题。维生素K缺乏胚胎病的大鼠模型显示，面部畸形之前，正常情况下无钙化的鼻中隔软骨会出现不受控制的钙化，且软骨纵向生长减少，从而导致上颌鼻发育不全。发育中的鼻中隔软骨通常富含维生素K依赖蛋白基质Gla蛋白（MGP）。有人提出，功能性MGP对于使生长中的软骨维持非钙化状态是必要的。发育中的牙齿同时含有MGP和第二种维生素K依赖蛋白，骨钙素（BGP）。据推测，这些蛋白在牙齿矿化中起功能性作用。目前尚未证实这一功能，在BGP和MGP应以无功能形式形成的情况下，也未观察到牙齿形成异常。
