Bonemetabolism inrheumatoid arthritis compared withpostmenopausal osteoporosis

SUMMARY Calciumandbonemetabolism in29rheumatoid arthritis (RA)patients were compared withthose in27postmenopausal osteoporotic patients. Signs ofvitamin D deficiency were foundin20RA patients, including 12whotookrecommended amountsofvitamin D in their diets andwere exposed tosufficient sunlight, andinnone oftheosteoporotic patients. There were no signs ofmalabsorption. Insixoutof15patients we foundincreased liver enzyme activity, whichmay havea roleinvitamin D metabolism. We proposetheinfluence of non-steroidal anti-inflammatory drugs(NSAIDs) on vitamin D metabolism intheliver as a possible explanation.