Study Population: We will recruit early RA patients (not more that 12 month duration of disease)with active joint inflammation cared for at this institution.Participants must be subjects with active RA at the time of inclusion, who are 18 years of age or older and have no history of other autoimmune disorders or other disorders such as cancer or osteoporosis which are also linked to vitamin D deficiency. The eligible patients with active RA should be on treatment for RA with Methotrexate at the time of inclusion. Patients taking anti-cytokine treatments (considered not standard) would be excluded. Other exclusions include hypercalcemia, and a history of renal failure or renal stones.