• Change in lumbar spine bone mineral density (BMD) and whole body bone mineral content (BMC) by dual-energy x-ray absorptiometry (DXA) [ Time Frame: Measured at Months 12 and 18 ] [ Designated as safety issue: No ]
  

• Changes in specific markers of bone turnover [ Time Frame: Measured at Months 3, 6, 12 and 18 ] [ Designated as safety issue: No ]
  
• Changes in growth parameters (for those who have not reached adult height) [ Time Frame: Measured at Months 3, 6, 12 and 18 ] [ Designated as safety issue: No ]
  
• Changes in body composition by whole body DXA scans [ Time Frame: Measured at Months 12 and 18 ] [ Designated as safety issue: No ]
  

Thalassemia is an inherited blood disorder that causes mild to severe anemia. In people with thalassemia, an abnormal or missing gene impairs the body's ability to make hemoglobin, a red blood cell protein that carries oxygen. Many individuals with this disease also have osteoporosis, which is likely caused by a combination of factors, including disease state, hormones, and nutrition. The nutrient zinc plays an important role in bone strength and is often deficient in people with thalassemia. The most effective way to prevent osteoporosis is to build strong, dense bones early in life. Correcting low zinc levels at an early age may prevent the onset of osteoporosis in people with thalassemia. The purpose of this study is to evaluate the effectiveness of zinc supplements in improving bone health in young individuals with thalassemia.

This 18-month study will enroll children and young adults with thalassemia and low bone mass. Participants will be randomly assigned to receive either 25 mg of zinc or placebo daily. Study visits will occur at baseline and Months 3, 6, 12, and 18. Each visit will include height, weight, and body fat measurements; blood and urine collection; and a health questionnaire. At baseline and Months 12 and 18, bone density will be measured with x-rays, and a food frequency questionnaire will be completed. At the baseline study visit, participants less than 21 years of age will have x-ray images taken of their hand to assess bone age, which is the degree of maturation of their bones. Study staff will monitor medication adherence through pill counts.