[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.


CONCLUSIONS
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.
Yin
Jing
J
Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Zhang
Qian
Q
Wang
Xiaoyan
X
Du
Weijing
W
D000293:Adolescent; D017195:Adolescent Nutritional Physiological Phenomena; D002118:Calcium / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D002648:Child; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007501:Iron / Q000493:pharmacokinetics*; D008297:Male; D015032:Zinc / Q000493:pharmacokinetics*
D007501:Iron; D015032:Zinc; D002118:Calcium