学前儿童膳食植酸摄入量及对锌生物利用率的影响

用改良的离子交换法测定了学龄前儿童膳食植酸的摄入量,并用植酸/锌摩尔比值及人体代谢平衡实验评价和观察植酸抑制锌吸收利用的程度。 膳食植酸平均摄入499mg/d,植酸/锌摩尔比值平均为6.66。当摄取植酸含量高的食物时,植酸/锌摩尔比值也仅达到10.6。而抑制锌吸收的临界比值范围为10～20。代谢平衡实验未观察到锌的生物利用率受到抑制。 因此,在我国目前的膳食条件下,锌缺乏与植酸关系不大。

PHYTIC ACID INTAKE AND ITS EFFECT ON THE BIOAVAILABILITY OF ZINC IN PRESCHOOL CHILDREN

Phytic acid intake of preschool children was measured with modified ion exchange method. Zinc bioavailability was assessed by metabolic balance experiment and phytic acid/zinc molar ratio was calculated.The average intake of phytic acid in the diet was 499mg/day. The average of phytic acid/zinc molar ratio was 6.66. Even the subjects ingested foods rich in phytic acid, the phytic acid/zinc molar ratio (10.6) still remained at the lower limit of the critical value (10-20), that will inhibit zinc bioavailability. Metabolic balance study indicated that zinc bioavailability was not inhibited.Therefore, the phytic acid in present Chinese diet is unlikely a factor of zinc deficiency among children.