In this study, our aims were to identify vitamin D levels in rheumatoid arthritis (RA) individuals as compared to controls and the impact of vitamin D levels on both objective and subjective assessments in RA patients. Methods: The current study was a prospective case-control study conducted on 108 RA patients and 50 agegender matched healthy controls. We first compared the levels of vitamin D among the RA patients and controls. Demographic and clinical data, parameters of disease activity, inflammatory markers, rheumatoid factor and anti-cyclic citrullinated peptide seropositivity and radiological damage scores were recorded in RA patients. These patients were also demanded to complete RA Quality of Life Questionnaire (RAQoL), fatigue severity scale (FSS) and Health Assessment Questionnaire (HAQ). Results: D vitamin levels in RA patients were significantly lower than healthy controls (p=0.001). Vitamin D deficiency was determined in 73% of the RA patients and 52% of the controls. Vitamin D deficiency was not associated with disease activity (p=0.862). There was no significant relationship among vitamin D levels and all subjective and objective assessments (p>0.05 for all). Conclusion: Vitamin D deficiency was common in RA participants than normal population. However, it was not shown that there was a significant relationship between vitamin D levels and objective and subjective assessments of disease, including disease activity, inflammatory markers, rheumatoid factor and anti-cyclic citrullinated peptide seropositivity, radiological damage scores, RAQoL, FSS and HAQ.