An Iodine Balance Experiment

Study Overview
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Brief Summary
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A 4-week study was conducted in 25 Chinese euthyroid women. Unified diets with different iodine contents (cooked with non-iodized salt or iodized salt) were provided in two different periods. The total iodine intake from diet, water and air as well as the total iodine excretion by urine, faces and respiration were monitored and determined, and a total of 300 samples were collected. The sweat iodine loss was also considered. Moreover, the regression curve model between the 24-h iodine intake and 24-h iodine excretion was also established.

Detailed Description
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The experiment was conducted between November and December with a total duration of 1 month. Referring to the experience from Harrison and Dworkin, however, considering the negative iodine balance reported, during the first 3 weeks, the diet was provided with non-iodized salt, while the diet with iodized salt was only offered in the last week. The total daily iodine intake consisted of dietary iodine intake, water iodine intake and iodine from breathing, while iodine could be excreted out of human body by urine, faces, sweat and breathing. The 24-h iodine intake and 24-h iodine excretion were determined in each individual participant, and the iodine balance was calculated accordingly.

Official Title
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Exploration of the Appropriate Recommended Nutrient Intake of Iodine in Chinese Euthyroid Women: an Iodine Balance Experiment

Conditions
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Iodine Deficiency, Nutritional Requirements

Intervention / Treatment
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* Dietary Supplement: iodized table salt, non-iodized table salt


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The ones with normal thyroid function, urinary iodine concentration, agree with the experiment. Exclusion Criteria: The ones with abnormal thyroid hormone level, urinary iodine concentration (UIC) or autoantibody-positive were excluded from the study.

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Participants received a diet with iodized table salt or non-iodized table salt
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: experimental period<br>the first period was with non-iodized salt, the second period was with iodized salt. | Dietary Supplement: iodized table salt, non-iodized table salt<br>* During the first 3 weeks, the diet was provided with non-iodized salt, while the diet with iodized salt was only offered in the last week.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total iodine intake and total iodine excretion | Iodine intake includes iodine from food, water and air (μg/d). | 12 days | 
| Total iodine excretion | Iodine excretion includes iodine excreted by urine, feces, sweat and breath (μg/d). | 12 days | 
| urinary iodine concentration (UIC) | μg/L | At the beginning of the experiment | 
| Thyroid function | FT3 (pmol/L), FT4 (pmol/L),TSH (mIU/L), TG (ng/mL), TGAb (IU/mL), TPOAb (IU/mL) | At the beginning of the experiment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Iodine, Balance experiment, EAR, Chinese women, Euthyroid