Data collection
Assessments for growth, development, and dietary intake were obtained from all participating children at baseline and at the six-month follow-up. Anthropometric measures were converted to z-scores per the World Health Organization (WHO) Growth StandardsBlood was then placed into a trace metal certified, S-Monovette® 5.5-ml plasma collection tube containing lithium heparin. No more than five milliliters were obtained from each child. The tubes were inverted 10 times and then placed on ice. Samples were centrifuged, and plasma was aliquoted into cryovials within one hour of the blood draw. Cryovials were stored in a − 20 °C freezer until the end of the day and then transferred on ice to a local laboratory, where they were placed in a − 80 °C freezer for long-term storage. The plasma aliquots were shipped on dry ice from Malawi to the University of California, Davis by international courier. Further aliquoting at University of California, Davis was performed to conduct various assays