National patterns of calcium use in osteoporosis in the United States.

OBJECTIVE: Although calcium intake is considered integral to appropriate management of osteoporosis, we hypothesized that the recent therapeutic dominance of bisphosphonates in osteoporosis treatment may have led calcium to be neglected as a component of effective management. STUDY DESIGN: Two national databases were used to assess the adequacy of calcium intake in patients with osteoporosis. Trends in reported supplemental calcium use among physician visits by patients with osteoporosis were assessed using nationally representative 1994-2004 IMS HEALTH National Disease and Therapeutic Index data. Quantity of calcium intake, from both supplements and food, among individuals with osteoporosis (n = 38 men and 376 women) was estimated using the 1999-2002 National Health and Nutrition Examination Survey (NHANES). RESULTS: Physician visits for osteoporosis in the United States increased 4.5-fold between 1994 (1.3 million visits) and 2004 (5.8 million visits). During this time the proportion of osteoporosis visits in which bisphosphonates were prescribed increased from 14% to 81%, while reported calcium use fell from 43% to 23% of visits. Among osteoporosis patients in NHANES, 64% reported using calcium-containing supplements. Reported median calcium intake was 433 (interquartile range: 295, 705) mg/d for calcium supplement nonusers and 1,319 (845, 1,874) mg for calcium supplement users. Overall, only 40% of osteoporosis patients had calcium intake exceeding 1,200 mg/d. CONCLUSION: While osteoporosis is increasingly identified and treated with effective medications, calcium is being neglected as a component of osteoporosis management. Despite the fact that the efficacy of new osteoporosis medications depends on adequate calcium intake, reported calcium intake in osteoporosis patients is far below recommended levels.