Effect of Zinc Supplementation on Bone Mineral Density in Osteoporotic Postmenopausal Women: A Double blind RCT

Aging is a cause of bone mass reduction and osteoporosis. Bone mass reduction is due to both decreased bone formation and increased bone resorption. Zinc, as an essential trace element, has been shown to have a stimulatory effect on osteoblastic bone formation and an inhibitory effect on osteoclastic bone resorption. The aim of this study was to investigate the effect of Zinc supplementation on bone mineral density (BMD). Methods and Materials: This double-blind RCT was conducted on 32 osteoporotic postmenopausal women referred to rheumatologic clinic. The patients were randomly divided into two groups: (1) Intervention group (n=14): who received 220 mg/day zinc sulfate containing 50 mg elemental zinc daily for 90 days and (2) Placebo group (n=19): who received a placebo for 90 days period. Demographic and clinical information were collected by filling in a questionnaire. Nutritional intake was assessed using a 3 day food recall at the baseline and at the final of trial and X-ray absorptiometry was used for BMD measurement at baseline and end of trial

Mean age and mean age of starting menopausal period was (57.96 and 48.61) years, respectively. There was no significant difference in age, level of education, anthropometric measures, and previous history of fracture between the groups at the baseline. BMD was improved up to 5.15% in intervention group compared with 2.8% in placebo group (P=0.08).

Zinc could improve BMD in postmenopausal osteoporotic women; however, further investigations are needed.