Quintuply-fortified salt for the improvement of micronutrient status among women of reproductive age and preschool-aged children in Punjab, India: protocol for a randomized, controlled, community-based trial

BACKGROUND: Multiple micronutrient (MN) deficiencies remain highly prevalent among women of reproductive age (WRA) and preschool-aged children (PSC) in many areas within India. Salt is an attractive vehicle for MN fortification in this context, as it is universally consumed in fairly consistent amounts and coverage of iodized salt (IS) is 94%. The overall objective of this trial is to evaluate the nutritional impact of quintuply-fortified salt with iron in the form of encapsulated ferrous fumarate, zinc, vitamin B12, folic acid, and iodine (eFF-Q5S) vs. quintuply-fortified salt with iron in the form of ferric pyrophosphate plus EDTA, zinc, vitamin B12, folic acid, and iodine (FePP-Q5S) vs. IS for the improvement of MN status among non-pregnant WRA and PSC. METHODS: The study is a community-based, randomized, controlled trial that will be conducted in Punjab, India. 780 non-pregnant WRA 18–49 years old and 468 PSC 12–59 months old will be enrolled and assigned to one of three intervention groups. Salt will be provided to participants monthly for 12 months. Primary outcomes include changes in mean concentration of biomarkers of iron, zinc, vitamin B12, folate and iodine. Secondary outcomes include changes in the composition of the gut microbiome, and discretionary salt intake of PSC. DISCUSSION: If proven efficacious, multiply-fortified salt (MFS) has the potential to drastically reduce the burden of MN deficiencies in India, and around the world. Although effectiveness research will be needed to examine the impact of MFS under programmatic conditions, salt fortification will piggy-back on existing platforms to produce IS and doubly-fortified salt (DFS), making it possible to scale-up the intervention quickly. TRIAL REGISTRATION: Clinicaltrials.gov: NCT05166980; date of registration: December 22, 2021. Clinical Trials Registry-India: CTRI/2022/040332 and CTRI/2022/02/040333; date of registration: February 15, 2022.