Bioavailability of Iodine for Natural Kelp and Iodized Salt in Young Adults

Summary

Iodine is an essential micronutrient for the production of thyroid hormones and its deficiecny remains a global problem impairing health. The primary source of iodine is the diet via consumption of foods, including cooked foods with iodized salt, dairy products, or naturally abundant seafood. Currently, the recommendation of dietary iodine intake is 150 μg per day in adults who are not pregnant or lactating. The ingestion of iodine or exposure above this threshold is well-tolerated and nearly no health problems are observed. The diets processed and cooked with iodized salt are generally important iodine sources, however, high iodine intake is a result of routine consumption of several kinds of edible algae in coastal regions, with varying contributions depending on the amount of seafood consumed.

Iodine absorption mainly depends on the iodine species in foods and possibly on the iodine status of the individual. Further, there was little available data on iodine absorption or bioavailability from different dietary sources, such as natutal kelp and fortified food with potassium iodide. To our knowledge, inorganic iodide is thought to be absorbed almost completely (over 90%). However, only about two-thirds of some forms of organically-bound iodine are absorbed. The different sources of iodine absorption have not been accurately quantified and compared in humans. Therefore, the purposes of this study were to quantify the iodine absorption of natural kelp in male and female adults and compare with the bioavailability from an iodine water solution (potassium iodide). This stduy will obtain the actual iodine bioavailability and the difference for different source of foods.

This study is a randomized, cross-over design and aims to evaluate the iodine bioavailability (measured using excretion in urine and fece) from different source and administered dose of iodine, such as natural kelp and potassium iodide delivering a dialy iodine intake about 600 µg and 1200 µg. This study will compare and measure to the ingestion of natural kelp and potassium iodide within one subject by three stages: (1) normal iodine intake stage (iodine intake \>150 µg/day); (2) intervention stage, a bowl of soup with an extrinsic iodine dose of about 600 µg; or a bowl of natural kelp with a certain iodine content of about 1200 µg potassium iodide.

Conditions

• Iodine Bioavailability

Interventions

DIETARY_SUPPLEMENT

iodine-containg spareribs soup

administrated a 150 ml - 200 ml of iodine-containg spareribs soup delivering ≈ 600 µg or 1200 µg iodine

DIETARY_SUPPLEMENT

intrinsic iodine in natural kelp

administrated 45 g or 80 g natural kelp delivering ≈ 600 µg or 1200 µg iodine (intrinsic iodine). The natural kelp will be approximately produced in an experimental barn feeding supplementary iodine to reach a final iodine intake of ≈ 600 µg or 1200 µg. The iodine intake of natural kelp will be adjusted to the required dose by determing iodine content in the natural kelp.

Sponsors & Collaborators

• Changzhi Medical College

  collaborator OTHER

• Shenzhen Center for Chronic Disease Control

  collaborator OTHER

• Liu Xiao Bing

  lead OTHER

Principal Investigators

• Xiaoguang Yang, Ph.D · National Institute of Nutrition and Health, China CDC

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

25 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-05-11

Primary Completion

2022-05-12

Completion

2024-05-12

Countries

• China

Study Locations