Salt Iodization: Meeting the Needs of Pregnancy, Lactation and Infancy (SIMPLIFY)

Salt Iodization and the 1st 1000 Days: Does a USI Program Cover the Iodine Requirement of Pregnant and Lactating Women and Infants?

The purpose of this study is to determine whether universal salt iodization (USI) meets the iodine requirements of pregnant women, lactating women and infants.

Study Overview

• Status: Completed
• Conditions: Iodine Deficiency

Detailed Description

Because pregnant women, lactating women and infants are the groups most vulnerable to iodine deficiency and its irreversible consequences, programs should focus on these groups. But like other mass fortification strategies, it is uncertain whether USI can meet the increased dietary requirements of pregnant women, lactating women and infants. Objective of this study to test whether USI can meet the dietary requirements of iodine in women of reproductive age, pregnant women, lactating women and infants up to 2 years of age without causing excess iodine intake in school children and non-pregnant non-lactating women. The study hypothesis is that USI, when fortified at adequate levels and applied to all salt consumed, including both household salt and salt used for processed foods, provides adequate dietary iodine for all population groups, except for weaning infants; while not posing any risk of excessive iodine intakes in other age groups.

• Study Type: Observational
• Enrollment (Actual): 8000

Contacts and Locations

Study Locations

• China
  • Shanxi
    • Linfen, Shanxi, China, 041000
      • Shanxi Institute for Prevention and Treatment of Endemic Disease
• Croatia
  • Zagreb, Croatia, 10000
    • University of Zagreb
• Philippines
  • Manila, Philippines
    • University of Santo Tomas Hospital
• Switzerland
  • Zurich, Switzerland, 8092
    • ETH Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 2 weeks to 44 years (Child, Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

In each of the four study countries, six population groups will be studied:

• women of reproductive age
• pregnant women
• lactating women
• young infants
• toddlers
• school-aged children

Description

Inclusion Criteria:

• living at study area for at least 6 months
• generally healthy
• no chronic medication
• no history of thyroid disease in the family
• no use of iodine containing dietary supplements during the last 6 months
• no use of iodine containing disinfectants for the last 6 months
• no use of X-ray / CT contrast agent or iodine containing medication within the last year
• in addition for women of reproductive age, pregnant women and breastfeeding women: age between 18 and 44 years old
• in addition for pregnant women: healthy pregnancy, singleton pregnancy (no twins or multiple pregnancy)
• in addition for breastfeeding women and breastfed infants: healthy pregnancy, singleton pregnancy (no twins or multiple pregnancy), baby born at full-term (in pregnancy week 38 to 42), the baby had normal birth weight (≥ 2500 g), baby not older than 6 months, baby currently completely breastfed (except for water, tea and juices)
• in addition for toddlers: between 6 and 24 months old

Study Plan

How is the study designed?

Number of groups / cohorts

6

Cohorts and Interventions

Group / Cohort
Women of reproductive age; Age: 18-44 years
Pregnant women; Age: 18-44 years
Lactating women; Age: 18-44 years
Young infants; Age: younger than 6 months
Toddlers; Age: between 6 and 24 months
School-aged children; Age: 6-12 years

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urinary iodine concentration (µg/L)	Participants will be assessed only once. However, for 30% of the study participants urinary iodine concentration will be assessed in spot samples collected on two different days, spread over an expected average of 5 days.	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thyroglobulin (µg/L)	Thyroglobulin will be measured in all population groups	1 day
Breast milk iodine concentration (µg/L)	Breast milk iodine concentration will be measured in lactating women.	1 day

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thyroid function (TSH, T4)	Thyroid function (TSH, T4) will be measured where relevant.	1 day
Urinary sodium excretion (mg/day)	Urinary sodium excretion will be assessed in school age children and women of reproductive age. Participants will be assessed only once. However, for urinary sodium excretion 30% of the study participants will be assessed in spot samples collected on two different days, spread over an expected average of 5 days	1 day

Collaborators and Investigators

• Sponsor: Swiss Federal Institute of Technology
• Collaborators: University of Zagreb; Global Alliance for Improved Nutrition; UNICEF; St. Luke's Medical Center; Shanxi Institute for Prevention and Treatment of Endemic Disease
• Investigators: Principal Investigator: Maria Andersson, PhD, ETH Zurich

Publications and helpful links

General Publications

• Dold S, Zimmermann MB, Jukic T, Kusic Z, Jia Q, Sang Z, Quirino A, San Luis TOL, Fingerhut R, Kupka R, Timmer A, Garrett GS, Andersson M. Universal Salt Iodization Provides Sufficient Dietary Iodine to Achieve Adequate Iodine Nutrition during the First 1000 Days: A Cross-Sectional Multicenter Study. J Nutr. 2018 Apr 1;148(4):587-598. doi: 10.1093/jn/nxy015.
• Dold S, Zimmermann MB, Aboussad A, Cherkaoui M, Jia Q, Jukic T, Kusic Z, Quirino A, Sang Z, San Luis TO, Vandea E, Andersson M. Breast Milk Iodine Concentration Is a More Accurate Biomarker of Iodine Status Than Urinary Iodine Concentration in Exclusively Breastfeeding Women. J Nutr. 2017 Apr;147(4):528-537. doi: 10.3945/jn.116.242560. Epub 2017 Feb 22.

Study record dates

Study Major Dates

• Study Start: July 1, 2014
• Primary Completion (Actual): January 1, 2016
• Study Completion (Actual): January 1, 2016

Study Registration Dates

• First Submitted: June 2, 2014
• First Submitted That Met QC Criteria: July 18, 2014
• First Posted (Estimate): July 22, 2014

Study Record Updates

• Last Update Posted (Estimate): April 19, 2016
• Last Update Submitted That Met QC Criteria: April 18, 2016
• Last Verified: April 1, 2016

More Information

Terms related to this study

• Keywords: Iodine deficiency
• Other Study ID Numbers: EK 2013-N-82

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO