Leprosy, a chronic granulomatous infection, presents with cutaneous and neurological manifestations. Musculoskeletal involvement, though the third most common manifestation, is underdiagnosed. 2 In its natural history, other immune manifestations besides articular manifestations may be present, such as the presence of autoantibodies. 4 There is evidence that vitamin D influences the activity of immune-mediated diseases, particularly autoimmune diseases. 6 Amazon is a state in the northern part of Brazil where the disease is endemic. It has a high level of sunshine, so a low prevalence of vitamin D insufficiency would be expected. In this study we looked at the serum vitamin D levels of such patients and demonstrate that manifestations such as arthritis and the presence of antinuclear antibodies (ANA) correlate with serum levels of vitamin D. Eighty-seven patients with leprosy were evaluated; 57 had lepromatous leprosy and 30 had borderline leprosy. Forty-four had a history of arthritis and 43 had no articular involvement. Forty-six healthy people living in the same region were selected as controls. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured by the Elecsys Roche automation. ANA were detected by conventional immunofluorescence using Hep-2 as substrate. Fifty-six patients had 25(OH)D levels above 30 ng/ml and 31 had lower values. Twenty-two were positive for ANAwhile only six of 46 controls were ANA positive (table 1). Patients with arthritis had lower mean 25(OH)D levels than those without arthritis (38.2 ng/ml vs 49.0 ng/ml, p<0.05) (figure 1A). The mean levels in patients positive for ANA were also lower compared with patients without ANA (p<0.001) (figure 1B and table 1). Statistical analysis was performed using the MannWhitney U test.