我国成人碘平衡研究

To establish iodine RNI for adults in China and prevent the damage of excessive and deficiency iodine intake , an iodine balance experiment in college students will be conducted.Different doses iodized diet and iodine supplements will be give to the twenty volunteers. Monitor the 24h iodine intake and 24h iodine output in the iodine balance experiment within 14 days, establish the regression curve model between iodine intake and iodine output, the iodine intake does when the “zero iodine balance” was reached is just the estimated average requirement(EAR); Then according to a relevant CV to calculate the iodine recommended nutrient intake(RNI).The experimental design has improved the regression model of iodine balance, remedied the technical conditions which limit the detection of the intake and output of breathing iodine. In addition, selected 20 volunteers to carry on the study of iodine metabolism within 14 days made the sample size reaches 280, which avoided the bias of iodine balance distribution.So, the results will not only provide data foundation to the formulatin of iodine RNI revision in domestic but also to revise the iodine DRIs in Chaina.

为研究我国成人碘的推荐摄入量，预防碘过量和碘缺乏对机体的危害，我们拟在大学生中开展随机分组的双盲碘平衡实验，通过给予20名志愿者不同剂量的含碘饮食及碘补充剂，研究其14天内24小时消化道、呼吸道的碘摄入量与24小时消化道、呼吸道及泌尿道的碘排出量之间的平衡关系，建立碘摄入量与碘平衡值的回归曲线模型，推算出受试者达到“零碘平衡”时的碘摄入量即为研究对象碘的平均需要量，从而根据相应的变异系数计算我国成人碘的推荐摄入量。该实验设计，由于完善了碘平衡回归模型、弥补了以往碘平衡实验中由于技术条件等限制未能检测的呼吸碘摄入及排出量，且对20人进行了14天的碘代谢研究，样本量达到了280例次，比以往研究样本量大大增加，避免了碘平衡的偏性分布；故本实验结果可为进一步研究制定我国成人碘推荐摄入量的制定提供实验数据，同时也将为我国DRIs的修订提供数据支持。

根据研究计划，我们在大学生中开展随机分组的双盲碘平衡实验，通过尿碘及甲状腺功能的检测，筛选了30名大学生志愿者，给予志愿者为期30天的规定的不同碘含量的膳食，并且采用双份饭法在实验期间四周中分别采集每周连续三天（包含周末（2天）和一个工作日）的膳食样品，同时收集连续三天的24h尿样和粪便样品，测定24h呼吸碘量。共计达到360例次。通过24小时消化道、呼吸道的碘摄入量与24小时消化道、呼吸道及泌尿道的碘排出量之间的平衡关系，建立碘摄入量与碘平衡值的回归曲线模型，推算出受试者达到“零碘平衡”时的碘摄入量即为研究对象碘的平均需要量，从而根据相应的变异系数计算我国成人碘的推荐摄入量。我们的实验结果表明，通过膳食每日碘摄入量达到199.97±63.96 μg/d时，每日尿碘排出约为108.81±38.13 μg/d，粪碘约为15.53（10.14,27.17） μg/d，呼吸碘约为0.62±0.30 μg/d；当膳食每日碘摄入量达到 494.94±179.52 μg/d时，每日尿碘排出约为234.28±67.00 μg/d，粪碘约为44.27（25.00,74.81） μg/d，呼吸碘约为0.62±0.30 μg/d，经计算，成人碘的适宜摄入量约为 70.5 μg/d。本研究是我国首次报道关于我国居民成人EAR的试验数据，将为我国居民碘的DRIs的修订提供重要参考数据。