Shenzhen Center for Chronic Disease Control, 2021 Bu Xin Road, Luo Hu District, Shenzhen, 518020, Guangdong, China.
Shenzhen Polytechnic, 7098 Liuxian Avenue, Nanshan District, Shenzhen, 518055, Guangdong, China.
Nutr J. 2022 May 30;21(1):35. doi: 10.1186/s12937-022-00775-z.
Appropriate iodine intake for adults is essential to reduce the prevalence of thyroid diseases, but there is little research data on iodine requirement of Chinese population. This study aimed to explore the iodine requirement of young adults to maintain a healthy status based on 'overflow theory'.
Iodine-balance experiment has been performed in this project. We conducted an 18-day study consisted of a 6-day acclimation period and 3 consecutive experimental stages in 37 Chinese healthy young adults (23 female and 14 male). Each stage was consumed for 4 days. Strictly-controlled low-iodine intake diets were provided for adults in the first period, an egg or 125mL milk was added in the second and third period, respectively. The dietary samples, 24-h urine specimens and faeces of volunteers were collected daily for assessment of iodine intake and excretion in volunteers.
Mean values of iodine intake (22.7±3.6, 35.1±3.7, and 52.2±3.8μg/d), excretion (64.7±13.9, 62.3±12.6, and 94.3±14.5μg/d) and iodine balance (-35.2±19.5, -21.0±19.8, and -33.5±26.9μg/d) were significantly different among three periods for male (P<0.001 for all); mean values of iodine intake (16.6±3.1, 29.7±2.7, and 48.0±2.7μg/d), and excretion (47.0±9.9, 55.5±8.1, and 75.7±12.4μg/d) were significantly different among three periods for female (P < 0.001 for all). No significant difference was observed among the 3 periods for female in the iodine balance (-30.5±9.3, -25.9±7.3, and -27.6±12.1μg/d). The linear regression equation of iodine excretion on iodine intake was Y=0.979X+37.04 (male) and Y=0.895X+31.48 (female). Compared with stage 2, iodine excretion increments in stage 3 had exceeded the iodine intake increment for men. The ratio of increment was 1.675 for male when the average iodine intake was 52.2μg/d in stage 3. When the iodine excretion increment equaled to the iodine intake increment, the daily iodine intake of men was 47.0μg.
We have evaluated the iodine requirement of young adults in southern China based on overflow theory. Our results indicate the lower limit of iodine requirement for Chinese young men is 47.0μg/d. The trial was registered at www.chictr.org.cn as ChiCTR1800014877.
成年人摄入适量的碘对于降低甲状腺疾病的发病率至关重要，但目前针对中国人群碘需求量的研究数据较少。本研究旨在基于“溢出理论”探讨年轻人维持健康所需的碘量。
本项目进行了碘平衡实验。我们对 37 名中国健康年轻成年人（23 名女性和 14 名男性）进行了为期 18 天的研究，包括 6 天的适应期和 3 个连续的实验阶段。每个阶段持续 4 天。在第一阶段，为成年人提供严格控制的低碘饮食，在第二和第三阶段分别添加一个鸡蛋或 125mL 牛奶。志愿者的膳食样本、24 小时尿液标本和粪便每天收集一次，以评估志愿者的碘摄入量和排泄量。
男性在三个阶段的碘摄入量（22.7±3.6、35.1±3.7 和 52.2±3.8μg/d）、排泄量（64.7±13.9、62.3±12.6 和 94.3±14.5μg/d）和碘平衡（-35.2±19.5、-21.0±19.8 和-33.5±26.9μg/d）差异均有统计学意义（P<0.001）；女性在三个阶段的碘摄入量（16.6±3.1、29.7±2.7 和 48.0±2.7μg/d）和排泄量（47.0±9.9、55.5±8.1 和 75.7±12.4μg/d）也存在显著差异（P<0.001）。女性在碘平衡（-30.5±9.3、-25.9±7.3 和-27.6±12.1μg/d）方面，三个阶段之间无差异。碘排泄量与碘摄入量的线性回归方程为 Y=0.979X+37.04（男性）和 Y=0.895X+31.48（女性）。与第二阶段相比，第三阶段的碘排泄量增加超过了男性的碘摄入量增加。当男性第三阶段平均碘摄入量为 52.2μg/d 时，碘摄入量增加的比例为 1.675。当碘排泄量增量等于碘摄入量增量时，男性的每日碘摄入量为 47.0μg。
我们根据溢出理论评估了中国南方年轻人的碘需求量。结果表明，中国年轻男性的碘需求量下限为 47.0μg/d。该试验在中国临床试验注册中心注册，注册号为 ChiCTR1800014877。
