Vitamin D plays a pivotal role in Craniofacial growth by regulating calcium-phosphorus balance, bone mineralization, and gene expression via the vitamin D receptor (VDR) in bone, cartilage, and dental tissues. Chronic deficiency defined by 25(OH)D levels below 20-30 ng/mL can impair jaw development, leading to underdeveloped maxilla or mandible, crowding, narrow arches, high palates, and increased risk of crossbites. Thus, ensuring adequate vitamin D levels during growth through sun exposure, diet, or supplementation is essential not only for systemic bone health but also for optimal craniofacial and dental development. This Dissertation contains the metabolism of Vitamin D in detail with particular emphasis of its effect in growth and development of the Craniofacial skeleton.