Vitamin D deficiency is a commonly observed health problem in the world. With a role in many chronic diseases and especially lung diseases, the importance of vitamin D deficiency in anesthesia management is increased. This research aims to investigate whether there is a correlation between the respiratory complications occurring in patients under general anesthesia and preoperative vitamin D levels.

This study included 95 adult cases aged from 18-65 years operated under general anesthesia. The cases had total 25-hydroxyvitamin D (25OHD) levels identified in blood samples before the operation. Patients given routine general anesthesia and postoperative monitoring procedures were assessed in terms of respiratory complications during anesthesia induction, extubation, anesthesia recovery and the first 24 hours postoperative.

This research observed that patients with low preoperative 25OHD vitamin levels encountered respiratory complications related to general anesthesia more often. Especially in the early postoperative period there is a very significant difference between complications and low 25OHD vitamin levels. Our study results show that low vitamin D levels may be a potential risk in terms of respiratory complications related to general anesthesia causing severe morbidity and mortality increase. The results lead to the consideration that optimizing vitamin D levels in the preoperative period for patients undergoing general anesthesia may aid in reducing complications.

Inclusion Criteria:

- American Society of Anesthesiologists I - II risk classification, healthy adult surgery cases

Exclusion Criteria:

• Thoracic surgery, those with severe respiratory, neuromuscular or endocrine system diseases, those with difficult intubation, morbid obesity, using vitamin D supplements and those who smoked