الفهرس 
Etiology and pathophysiologyOnly 14 pages are availabe for public view
 |  | from | 170 |  |  |
| | | from | 170 | | |
Abstract
Letrozole is an essential drug in the treatment of breast cancer. Arthralgia and musculoskeletal problems are the most significant adverse effect. There is no standard agent for the treatment or prevention of letrozole induced arthralgia. In this randomized controlled parallel study, forty postmenopausal estrogen receptor positive women with breast cancer were randomized into 2 groups; the control group (n=20) which received letrozole 2.5 mg daily for 6 months, and the vitamin D3/calcium supplementation group (n=20) which received letrozole 2.5 mg daily in addition to 2000 IU vitamin D3 and 1000 mg of calcium daily for 6 months. The efficacy of vitamin D and calcium supplement was evaluated biologically through measuring the change in the serum levels of vitamin D3, total and ionized calcium, phosphorous, osteocalcin, alkaline phosphatase (ALP), phosphorous, and intact parathyroid hormone (I-PTH). Bone mineral density was also measured. Also, the effect vitamin D and calcium supplement was assessed clinically through health assessment questionnaire- II (HAQ-II) and pain scores. Patients received vitamin D3/calcium supplementation showed significant elevation in the serum concentrations of vitamin D3, calcium and phosphorus and significant decline in the serum levels of parathyroid hormone and osteocalcin. In addition vitamin D3/calcium supplementation resulted in an improvement in bone mineral density which was associated with less pain and musculoskeletal symptoms.