## 4 Discussion  
Despite extensive research, medication-related osteonecrosis of the jaw (MRONJ) remains a challenging condition to treat effectively. Numerous treatment approaches, both surgical and non-surgical, were proposed [33]. The selection of an appropriate treatment strategy must consider the advanced age of many patients and their complex medical histories, which often include malignancies with metastases [30]. The overall health situation of MRONJ patients may not always allow for surgical treatment, which is associated with the highest percentage of complete cures. Patients with numerous comorbidities or advanced-stage neoplastic disease may not always achieve a complete resolution of MRONJ. In such cases, treatment focuses on managing the chronic nature of the disease, alleviating negative symptoms such as severe pain or difficulties in eating. Success, in these instances, is often not defined by a complete cure but by reducing the disease to a form that does not interfere with daily functioning. This has led to an increased exploration of less invasive conservative treatments and alternative therapeutic options [30,33]. Furthermore, factors such as the route of administration of antiresorptive drug (ARD) therapies play a significant role in treatment outcomes. Patients receiving intravenous ARDS tend to experience a more severe disease course and a more advanced stage of MRONJ [32]. The duration of bisphosphonate use is also a crucial factor; according to [PERSON] et al. (2018), patients who used bisphosphonates for more than 12 months tend to respond poorly to treatment and present with more advanced disease at the time of diagnosis [34]. Thanks to the development of newer treatment regimens for MRONJ each year and greater awareness of the disease's progression, clinicians and researchers can now focus on a detailed examination of the role of various factors within the broader treatment protocol. However, there is a paucity of clinical studies addressing the specific relationship between vitamin D levels and the treatment and prevention of MRONJ [35]. Therefore, this clinical study aimed to investigate the effect of vitamin D at different stages of the disease, as well as its impact on the risk of developing MRONJ. A study published in 2020 by [PERSON] et al. found that vitamin D levels are associated with the risk of MRONJ [36]. The objective of our study was, among other things, to correlate vitamin D levels with the risk of MRONJ development, considering the disease's stage. Our findings revealed that patients with vitamin D levels above 30 ng/mL at the time of MRONJ diagnosis exhibited a lower stage of disease compared to those with levels below 30 ng/mL. Similar reports from 2018 also indicated a correlation between serum vitamin D levels, suggesting that appropriate dosing could potentially protect against the development of osteonecrosis [8,35]. Our statistical data further confirm that vitamin D deficiency, defined as levels below 30 ng/mL, is associated with a higher risk of developing severe osteonecrosis, particularly in stage III. These results partially align with the findings of [PERSON] et al. from 2017 [35]. It should also be noted that surgical procedures for MRONJ are complex, and the risk of complications, such as wound dehiscence or impaired healing, is high [37]. The study also aimed to evaluate the effect of vitamin D supplementation during surgical procedures in patients receiving antiresorptive drugs (ARDs), specifically in the context of tooth extraction and its potential role in preventing the occurrence of MRONJ. The findings clearly indicated that the absence of vitamin D supplementation during tooth extraction procedures significantly increased the risk of severe necrosis at stage III. Patients who did not receive vitamin D supplementation during oral surgery exhibited a more advanced degree of MRONJ, if the disease developed, compared to those who were supplemented with vitamin D during the extraction process.