An Iodine Balance Study to Investigate the Recommended Iodine Intake in an Elderly Population

An Iodine Balance Study in the Elderly

Current Chinese dietary iodine reference intake (DRIs) standards lack direct data on recommended iodine intake (RNI) in the elderly. The elderly have a high prevalence of thyroid diseases. The risk threshold of iodine intake in the elderly is unknown. Identifying the appropriate iodine intake for the elderly to maintain optimal thyroid function to reduce the burden on medical resources is a public health issue requiring high attention. The iodine balance study is an important method for exploring physiological iodine requirements. Few iodine balance studies have been conducted in the elderly. This study aimed to conduct an iodine balance study and provide information on the appropriate iodine intake level for elderly people.

The investigators measured subjects' food and water intake throughout the day using weighing methods, and collected all urine and fecal samples. Food, drinking water, fecal and urine samples were taken to determine iodine concentrations. Each subject was required to participate in two phases of iodine balance studies. Each stage lasts 4 to 10 days. There was no intervention in the first half of the experiment, and there was an intervention of iodized salt/non-iodized salt consumption in the second half of the experiment. The appropriate level of iodine intake for the elderly was explored by fitting and analyzing the dose change relationship between iodine intake and iodine excretion.

The target population of this study is elderly people over 60 years old. Adults living in the same household can also participate.

Inclusion Criteria:

1. aged 18 and above;
2. at least 5 years of local residence.

Exclusion Criteria:

1. family genetic diseases；
2. special dietary habits；
3. taking iodine-containing drugs or supplements；
4. metabolic diseases;
5. thyroid diseases.