Location: Methods and Application of Food Composition Laboratory
Project Number: 8040-52000-068-047-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jul 29, 2019
End Date: Sep 30, 2021
Objective:
This project, Phase 2, focuses on major contributors of iodine in the current United States food supply. In the face of deficiency in many areas around the globe, the growing consumption of commercially prepared foods using non-iodized salt, and the potential risk to women of child-bearing age, pregnant women and most acutely, their growing fetuses, the need for iodine data to assess status, assess intakes, and develop interventions, is critical. The goal of the second phase of this project is extended collaboration to link iodine composition data with the Food and Nutrient Database for Dietary Studies (FNDDS)/What We Eat in America (WWEIA). This will allow estimation (within limits) of iodine intake in previous and future National Health and Nutrient Examination Survey (NHANES) surveys. This complements the MAFCL study of the iodine content of human dietary supplements to determine total intake and the iodine content of both food and human dietary supplements. This is especially important for maternal iodine intake where intakes that are either too low or too high can be detrimental.
Approach:
USDA and FDA will work together to map iodine values to WWEIA once final analyses are completed and the two datasets merged. The focus initially will be on the foods reported eaten by NHANES respondents from whom urinary iodine was determined. The first few months will be spent assessing remaining needs for analytical values. Sampling/analyzing these foods should be completed before mapping and the datasets merged from FDA and USDA (analytical data only, ~500 foods). Food scientists at USDA and FDA will map iodine to WWEIA foods using the FDA experience of mapping to NHANES. These studies will be presented at the 2019 International Food Data Conference and the composition data are being prepared for inclusion in the USDA FoodData Central as a Special Interest Database.
The following steps are in progress: development of NHANES 2014 iodine data field, using the subsamples of participants who took part in the 24 hour urine collection study (approximately 900 participants) and expand to all NHANES 2013-2014 foods, allowing estimation of intake in larger population. In some cases, an assumed “0” will be assigned when no iodine (based on similar foods and recipes/formulations) is expected. Identify extra foods for analysis and conduct needed assays (ongoing). As intake assessments are completed for 2013-2014, the data may be expanded to subsequent NHANES releases and to all participants.
As need demands, archived samples of foods may be analyzed for iodine if it is expected they are contributing to intake e.g., breads containing potassium iodide as a dough conditioner.
