The objective of this study is to evaluate the prevalence of vitamin D insufficiency in patients with rheumatoid arthritis (RA) and its association with disease activity, severity and physical disability. We included patients with rheumatoid arthritis followed in Rheumatology Department of Hassan II University Hospital, Fez, Morocco. Patients suffering from liver and kidney insufficiency and those who had received vitamin D in the previous 12 months have been excluded. Statistical analysis was done using SPSS v 18. A bivariate analysis and logistic regression were used to identify factors associated with vitamin D deficiency. One hundred seventy patients were included with a mean age of 50 ± 12.1 [17-83] years, and a female predominance (88.1%). All of our patients had hypovitaminosis D. The prevalence of 25(OH)-D insufficiency and deficiency was 64.5 and 35.5% successively. In unadjusted analysis, vitamin D concentration was inversely associated with pain visual analog scale VAS score (p < 0.001), asthenia VAS (p < 0.001), morning stiffness (p = 0.03), number of tender joints (p = 0.004), number of swollen joints (p < 0.001), inflammatory markers (p = 0,012), Disease Activity Score (p = 0.009), physical disability using Health Assessment Questionnaire (HAQ) (p = 0.001), and severity of the disease (p < 0.001). After logistic regression persisted association with female sex (OR = 4.3, CI = [0.94 to 20.976], p = 0.05), asthenia VAS (OR = 1.029, CI = [1.011 to 1.046], p = 0.001), and with the severity of the disease (OR = 2.910, CI = [1.314-6.441], p = 0.008). The vitamin D deficiency is common in our patients with RA. This deficiency is associated with female sex, severe asthenia, and the severity of the disease.