Background <p>Knee osteoarthritis (OA) is a prevalent condition influenced by various biochemical, anatomical, and lifestyle factors. Vitamin D deficiency has been implicated in OA, but its role in disease severity and associated symptoms remains unclear. We aimed to investigate the prevalence of vitamin D deficiency in knee OA patients and its relationship with inflammatory markers and clinical symptoms.</p> Methods <p>This retrospective study analyzed 986 patients with knee OA over a 3.5-year period. Vitamin D levels, ESR, and platelet counts were assessed, along with demographic and clinical data. Statistical analyses were conducted to explore associations.</p> Result <p>This study involved 986 patients with knee OA, majority of them (85% ) were female with mean age 52.95 ± 12.44 years. More than half of patients 59.7% had unilateral knee OA and 40.3% had bilateral knee OA. The mean value of Vitamin D3 was 25.35 ± 14.125. Vitamin D deficiency was observed in 70.9% of patients, with moderate deficiency being most prevalent (36.94%). No significant association was found between vitamin D levels and inflammatory markers. However, a strong association was observed between vitamin D deficiency and symptoms like polyarthralgia (<i>p</i> &lt; .05)., Bilateral OA was associated with higher vitamin D deficiency levels compared to unilateral OA (<i>P</i> &lt; .001).</p> Conclusion <p>OA more prevalence among female .As well as, vitamin D deficiency is highly prevalent in knee OA patients and its severity associated with Bilateral OA and polyarthralgia but not with inflammatory markers. Future research should focus on the long-term impact of vitamin D supplementation and the molecular mechanisms underlying these disparities.</p>