Aim: To investigate the relation of vitamin D concentration and parathyroid hormone with insulin resistance in PCOS women. Methods: In the department of Obstetrics and Gynecology at Dr. Baba Saheb Ambedkar Medical College & Hospital, Rohini, Delhi, a one-year observational study was conducted. The levels of 25, hydroxyvitamin D and PTH, as well as the levels of fasting sugar and insulin in the blood, were tested. Results: There was a 91.0 percent prevalence of vitamin D insufficiency (<20 ng/ml) in the study, whereas 67.9 percent of participants had an elevated parathyroid hormone level. According to the study, vitamin D insufficiency (r=-0.64, p=0.01) had a significant negative connection with the HOMA-IR. Increased PTH levels were shown to have a positive correlation with HOMA-IR. Conclusion: Women with PCOS who have high parathyroid hormone levels or vitamin D insufficiency have a higher incidence of glucose intolerance. If vitamin D insufficiency and insulin resistance are strongly linked, it may be possible to treat insulin resistance by raising vitamin D levels.