Serum zinc and its relation to bone mineral density in beta-thalassemic adolescents.

Trace elements have been considered to play critical roles in bone metabolism. This study aims at determining the serum zinc profile and its association with bone mineral density (BMD) abnormalities in thalassemic patients. In 131 transfusion-dependent beta-thalassemic patients, aged 10-20 yr, serum levels of zinc were measured by flame atomic absorption spectrophotometry (F-AAS). BMD values at the lumbar (L1-L4) and femoral neck were determined by dual X-ray absorptiometry (DXA). Dietary zinc intake and daily consumption of calcium were evaluated by a food-frequency questionnaire. Low serum zinc was found in 84.8% (in 44.7% severely low). Below -2 BMD Z-scores were observed in 68.7% and 17.6% of the patients at the lumbar and femoral regions, respectively. Female patients with severe zinc deficiency had lower lumbar BMD Z-scores in comparison to the other females (-3.26 vs -2.54). Serum zinc in females with femoral BMD Z-scores < - 2 was significantly lower by 16.4 microg/dL than other females. Our study suggests that serum levels of zinc can be lowered in the thalassemic patients and partly affect the BMD.