## 4 Discussion
Similar effects of vitamin D on the risk of developing MRONJ were demonstrated in animal studies conducted by [PERSON] et al. [38]. Moreover, in the current study, we also compared the impact of high-dose vitamin D supplementation on postoperative healing in patients who received supplementationversus those who did not during both the surgical treatment and healing phases. Healing was classified as difficult in cases of wound dehiscence, incomplete wound closure, bone exposure, or persistent local inflammation, including purulent drainage. No correlation was found between the lack of vitamin D supplementation and complications in postoperative healing. Furthermore, the same group of patients was assessed for the complete healing of MRONJ. The results suggest that active vitamin D supplementation during both the surgical treatment and healing phases did not significantly predict complete healing of MRONJ when compared to patients who did not receive vitamin D supplementation. It is important to note that these findings refer to two different clinical contexts. The beneficial effect of vitamin D we observed was primarily in its prophylactic role--when vitamin D supplementation occurred before or during tooth extraction, thus reducing the likelihood of developing an advanced stage of MRONJ later. In contrast, in patients who already had active MRONJ, vitamin D supplementation alone did not significantly alter surgical or postoperative complication rates. By clarifying this distinction, our study highlights that vitamin D may help prevent severe necrosis if administered early but may not substantially affect outcomes once MRONJ is fully established. This leads to the conclusion that the most important thing seems to be to continue supplementation during the entire oncological and osteoporosis treatment and to maintain continuous exogenous vitamin D supply, because the results indicate the importance of supplementation and vitamin D levels already during surgical procedures before the occurrence of MRONJ--in our case, tooth extraction in patients taking bisphosphonates and maintaining a moderate level of vitamin D in the serum to alleviate symptoms and prevent the development of advanced MRONJ. The influence of vitamin D levels as a risk factor for the development of MRONJ is still controversial, but our study argues for the importance of vitamin D supplementation in people at risk of developing osteonecrosis in order to prevent and prevent the development of this disease entity. The findings of the study lead to the conclusion that continuous supplementation of vitamin D throughout the course of oncological and osteoporosis treatment is crucial, as maintaining a steady exogenous supply of vitamin D appears to play a key role. The results suggest the importance of vitamin D levels during surgical procedures, particularly prior to the occurrence of MRONJ--such as tooth extraction in patients receiving bisphosphonates. Maintaining a moderate level of vitamin D in the serum may help alleviate symptoms and prevent the development of advanced MRONJ. While the role of vitamin D levels as a risk factor for MRONJ remains controversial, our findings support the significance of vitamin D supplementation for individuals at risk of developing osteonecrosis, both as a preventive measure and as a strategy to mitigate the progression of this disease. Recent evidence underscores the importance of not only vitamin D3 but also vitamin D2 in achieving adequate serum vitamin D levels. A meta-analysis by [PERSON] et al. (2024) examined the time and dose-response relationship of vitamin D2 supplementation in humans and demonstrated that optimal dosing regimens can significantly increase serum vitamin D concentrations. While most clinical recommendations for MRONJ prevention and management focus on vitamin D3, these findings suggest that appropriate vitamin D2 supplementation strategies could be equally relevant.