This report assesses the health effects of mandatory folic acid and iodine fortification, introduced to help reduce the prevalence of neural tube defects and address the re emergence of iodine deficiency in the population. Mandatory fortification resulted in increased levels of folic acid and iodine in the food supply, increased folic acid and iodine intakes, a decreased rate of neural tube defects in Australia, and improved iodine status in the general populations in Australia and New Zealand.