Changes in analytes over time. A. Haemoglobin. B. Serum total homocysteine. C. Serum folate. D. Red-cell folate. Severe dietary folate deficiency commenced on Day 0 (23 May 2011). The folate-replete diet, with folate supplementation, resumed on day 586 (29 December 2012), and recovery was complete on day 772 (3 July 2013). The dotted lines in panels A, C and D are the minimum normals, and the long-dashed line in panel A is the maximum normal, according to Bates and Lewis (2012). The dotted line in panel A is also the WHO (2011) haemoglobin concentration for mild anaemia; the short-dashed line is the WHO concentration for moderate anaemia and the dot-dashed line is the WHO concentration for severe anaemia. The short-dashed line in panel B is the upper limit for patients with high coronary risk factors (Stanger et al. 2004), and the long-dashed line is the upper limit in case of normal coronary risk factors (Brouwer et al. 1998). The short-dashed lines in panel D are the low end of the reference range, or a minimum cut-off value, as quoted by each testing laboratory.