Role of Vitamin D and Calcium in Epidermal Wound Repair

The study highlighted the essential roles of vitamin D and calcium in epidermal wound repair. It was found that deficiencies in vitamin D, calcium, or their receptors (VDR and Casr) led to delayed wound healing. This delay was attributed to a reduction in stem cell numbers and their activation in both the hair follicle and interfollicular epidermis. The formation of the E-cadherin/catenin complex, regulated by vitamin D and calcium, was crucial for epidermal differentiation, maintaining the stem cell niche, and enabling stem cell progeny to migrate and re-epithelialize the wound. Additionally, catenin b1 signaling, which was reduced in VDR null epidermis, was necessary for stem cell activation and proliferation in response to wounding. Therefore, vitamin D and calcium signaling were critical for stem cell maintenance, activation, migration, and differentiation during wound repair.