Figure 1From: Folic acid fortification and public health: Report on threshold doses above which unmetabolised folic acid appear in serum This flow diagram illustrates diagrammatically the interventions and sampling points. Schematic summary of intervention phases and sample collection. * = Folate and Folic Acid blood sample. RCF = Red cell folate blood sample. § = Day 7, trial of bread regimes (200 μg, 100 μg, 50 μg).Back to article page