Iron and zinc deficiency remain a major worldwide public health problem, especially in developing countries such as India. In this randomized study, 700 children aged 12-18 months from Mumbai, Maharashtra, India will be fed either iron and zinc biofortified pearl millet or control pearl millet three times per day, six days per week, for nine months. The goal of this study is to examine the effects of iron and zinc biofortified millet on immune function, growth, and cognitive function in this age group. The key outcome measures are biomarkers of iron and zinc status, growth, and immune function. Serum concentrations of hemoglobin, ferritin, serum transferrin receptor, and zinc will be assessed at enrollment (baseline), at an intermediate time point (midline; random serial sampling) and after 9 months of follow-up (endline). Additionally, we will measure concentrations of C-reactive protein (CRP) and alpha 1-acid glycoprotein (AGP), as iron and zinc biomarkers can be influenced by inflammation. To assess cognitive function in a subset, multiple specific aspects of memory, attention, and processing speed will be assessed. Higher-level, integrative cognitive abilities that require the coordination of multiple specific functions, such as problem-solving and exploratory behavior and global aspects of attention during free play with toys, will also be assessed.