1. Micronutrient Initiative; Ottawa Ontario Canada K2P 2K3
2. Division of Clinical Epidemiology; McGill University Health Centre; Montreal Quebec Canada H3A 1A1
3. Department of Epidemiology, Biostatistics and Occupational Health; McGill University; Montreal Quebec Canada H3A 1A1
4. Centre for Indigenous Peoples' Nutrition and Environment (CINE) and, School of Dietetics and Human Nutrition; McGill University; Ste-Anne-de-Bellevue Quebec Canada H9X 3 V9
5. World Vision Ecuador; Quito Ecuador