The benefit and risk of calcium supplements in the treatment of osteoporosis in the elderly population

Osteoporosis is prevalent in old people particularly in postmenopausal women, and osteoporotic fracture is an important cause of disability and morbidity in the elderly population. Treatment of high risk individuals can decrease the risk of fracture and improve life quality. Although calcium is the mainstay of treatment for osteoporosis, but recent studies have found that Its benefits are negligible against its side effects.This study aims to review the effect of calcium supplementations in the prevention of bone mineral density (BMD) loss and fractures by review of PubMed with keywords such as calcium supplements,vitamin D, osteoporosis, BMD, fracture, prevention, complicaltions. Recent findings A dietary intake of 1200 mg elemental calcium in split daily dosing with 800–1000 IU vitamin D per day has been recommended by the National Osteoporosis Foundation for treatnent of postmenopausal osteoporosis. This can provide necessary calcium for optimal effects of antiosteoporotic drugs in the treatment of osteoporosis. Furthermore, calcium alone or in combination with vitamin D is recommended for primary prevention of bone loss or bone fractures in the elderly population, particularly postmenopausal women.Efficacy of calcium supplement for prevention of bone loss and bone fractures has been investigated in several studies comprised elderly women and men, but the results are conflicting. At present there is no evidence to suggest calcium supplements or vitamin D alone or in combination for prevention of BMD loss or reducing the risk of fractures in older people. However, a few studies have shown a small increase in BMD by calcium supplementation in early stage of postmenpausal period, but this benefit decreased to pretreatment level after withdrawal of calcium supplements. On the other hand recents studies have raised concerns about the safety of using calcium supplements in regard to increased cardiovascular events, kidney stones, gastrointestinal symptoms, and hospital admissions. For these reasons several studies have attempted to investigate the effects of increasing dietary calcium on BMD and bone fractures, because low calcium intake is prevalent particularly in men and women older than 70 years of age and increasing dietary calcium has not been shown to be associated with increased risk of cardiovascular events. Nonetheless, a systematic review of RCTs revealed no evidence for increasing calcium intake from dietary sources to prevent fractures. However in institutionalised women and men in whom intake of calcium is inadequate,increasing dietary calcium has shown some benefits in prevention of fractures. Nonethelss, based on a meta-analysis of 19 RCTs and 28 observational studies, there is insufficient evidence in respect to benefits or harms of daily supplemental calcium vitamin D in noninstitutionalized postmenopausal women or primary prevention of fractures in premenopaussl women or men. Conclusion It is hypothesized that, the serum calcium is tightly controlled by the parathyroid-vitamin D -kidney system and bone remodeling as an active process maintains BMD. Therefore, increasing serum calcium by supplementation in subjects with adequate dietary intake is not expected to increase bone formation.Based on the existing data, the risk- benefit ratio of calcium supplements in preventing osteporosis or bone fractures is unfavorable. Regarding an association of calcium supplementation with cardiovascular and cerebrovascular complications, routine administration of calcium supplements in perimenopausal or postmenopausal women to prevent occurence of osteoporosis or fractures seems to be unreasonable.However, in subjects with insufficient dietary calcium intake, in particular osteoporotic patients, calcium supplement or increasing dietary calcium should be recommended.

کلیدواژه ها:

Calcium supplements ، osteoporosis ، fractures ، benefits ، complications