The impact of mandatory fortification of flour with folic acid on the blood folate levels of an Australian population.

Objective: To determine the impact that mandatory fortification with folic acid of wheat flour used in breadmaking has had on the blood folate levels of an Australian population since it was introduced in September 2009.

Design, Setting And Patients: A retrospective analysis of serum and red blood cell (RBC) folate levels of 20,592 blood samples collected between April 2007 and April 2010 from a wide variety of inpatients and outpatients and analysed in a large public hospital diagnostic pathology laboratory.

Main Outcome Measures: Prevalences of low levels of serum and RBC folate and monthly mean levels before and after introduction of mandatory fortification.