补钙对12～17岁青少年锌、铁吸收率的影响

目的通过代谢平衡实验探讨补钙对中国青春期少年锌、铁吸收率的影响。方法从320名参加1年补钙实验的4组12~17岁少年中,每组随机抽取男、女生各10人,共80人。采用代谢平衡的方法,收集研究对象10天内摄入的食品、排出的粪便和尿液样品,用电感耦合等离子体发射光谱法测定样品中的钙、铁、锌含量。结果不同补钙组之间钙摄入量有差异,但铁、锌摄入量差异无显著性。不同补钙组之间钙、铁、锌的表观吸收率差异无显著性。男生钙、铁、锌的表观吸收率平均为69.4%、12.5%和29.9%,女生的分别为46.4%、20.9%和35.3%。铁的表观吸收率与青春发育水平有关。男生钙摄入量为600~800mg/d时,钙、铁、锌的表观吸收率均处于相对较高水平(75.3%、23.2%和36.4%)。结论钙摄入量低于1400mg/d时,不影响12~17岁少年锌、铁的吸收率。当男生钙摄入量为600~800mg/d时,更有助于钙、铁、锌的吸收。

Effect of calcium supplementation on absorption rates of zinc and iron in 12-17 years old adolescents

Objective To study the effect of calcium supplementation on absorption rate of zinc and iron by calcium metabolic balance study. Methods A total of 80 students (12-17 years old) were selected randomly from 320 subjects who had been supplemented with calcium supplementation for one year. 10 boys and 10 girls were randomly selected from each calcium supplementation group to attend a 10-day metabolic balance study. Samples of foods, feces and urine were collected. Calcium, zinc and iron in samples were measured with ICP-AES. Results There were significant differences of calcium intake, but were no differences of iron and zinc intake for 4 groups. The apparent absorption rate of calcium, iron and zinc in boys and girls were 69.4%, 12.5%, 29.9% and 46.4%, 20.9%, 35.3%, respectively. Absorption rates of iron were associated with pubertal stages. There were no significant differences of absorption of calcium, iron and zinc for 4 groups. Apparent absorption rates of calcium, iron and zinc seemed higher (75.3%, 23.2% and 36.4%) when the level of calcium intake were 600-800mg/d in boys.Conclusion There were no significant effects on absorption rate of iron and zinc when the level of calcium intake was 1400mg/d in 12-17 years old Chinese adolescents. Absorption rates of calcium, iron and zinc seemed higher when the level of calcium intake was 600-800mg/d in boys.