Calcinosis of joints and periarticular tissues associated with vitamin D intoxication.

We describe a patient with rheumatoid arthritis and widespread joint and periarticular calcinosis related to self-medication with vitamin D, which was aggravated by oral phosphate therapy prescribed for her hypercalcaemia. Hydroxyapatite was shown in the synovial fluid from affected joints. The role played by tissue injury in the pathogenesis of soft tissue calcification is discussed.