1. MRC Vitamin Study Research Group (1991) Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet 338, 131–137.
2. Gomes, S, Lopes, C & Pinto, E (2016) Folate and folic acid in the periconceptional period: recommendations from official health organizations in thirty-six countries worldwide and WHO. Public Health Nutr 19, 176–189.
3. Ray, JG, Singh, G & Burrows, RF (2004) Evidence for suboptimal use of periconceptional folic acid supplements globally. BJOG 111, 399–408.
4. Gebreamlak, B, Dadi, AF & Atnafu, A (2017) High adherence to iron/folic acid supplementation during pregnancy time among antenatal and postnatal care attendant mothers in governmental health centers in Akaki Kality Sub City, Addis Ababa, Ethiopia: hierarchical negative binomial Poisson regression. PLoS One 12, e0169415.
5. Nisar, Y Bin, Dibley, MJ & Mir, AM (2014) Factors associated with non-use of antenatal iron and folic acid supplements among Pakistani women: a cross sectional household survey. BMC Pregnancy Childbirth 14, 305.
6. Titaley, CR & Dibley, MJ (2015) Factors associated with not using antenatal iron/folic acid supplements in Indonesia: the 2002/2003 and 2007 Indonesia Demographic and Health Survey. Asia Pac J Clin Nutr 24, 162–176.
7. Stockley, L & Lund, V (2008) Use of folic acid supplements, particularly by low-income and young women: a series of systematic reviews to inform public health policy in the UK. Public Health Nutr 11, 807–821.
8. Morton, SMB, Grant, CC & Carr, PEA (2013) Too many left at risk by current folic acid supplementation use: evidence from Growing Up in New Zealand. Aust N Z J Public Health 37, 190–191.
9. Feng, Y, Wang, S, Chen, R et al. (2015) Maternal folic acid supplementation and the risk of congenital heart defects in offspring: a meta-analysis of epidemiological observational studies. Sci Rep 5, 8506.
10. Hodgetts, VA, Morris, RK, Francis, A et al. (2015) Effectiveness of folic acid supplementation in pregnancy on reducing the risk of small-for-gestational age neonates: a population study, systematic review and meta-analysis. BJOG 122, 478–490.
11. Roth, C, Magnus, P, Schjølberg, S et al. (2011) Folic acid supplements in pregnancy and severe language delay in children. JAMA 306, 1566–1573.
12. Roza, SJ, van Batenburg-Eddes, T, Steegers, EAP et al. (2010) Maternal folic acid supplement use in early pregnancy and child behavioural problems: the Generation R study. Br J Nutr 103, 445–452.
13. Barua, S, Kuizon, S, Brown, WT et al. (2016) DNA methylation profiling at single-base resolution reveals gestational folic acid supplementation influences the epigenome of mouse offspring cerebellum. Front Neurosci 10, 168.
14. Gao, Y, Sheng, C, Xie, R-H et al. (2016) New perspective on impact of folic acid supplementation during pregnancy on neurodevelopment/autism in the offspring children – a systematic review. PLoS One 11, e0165626.
15. Schmidt, RJ, Tancredi, DJ, Ozonoff, S et al. (2012) Maternal periconceptional folic acid intake and risk of autism spectrum disorders and developmental delay in the CHARGE (CHildhood Autism Risks from Genetics and Environment) case–control study. Am J Clin Nutr 96, 80–89.
16. Surén, P, Roth, C, Bresnahan, M et al. (2013) Association between maternal use of folic acid supplements and risk of autism spectrum disorders in children. JAMA 309, 570.
17. Choi, J, Yates, Z, Veysey, M et al. (2014) Contemporary issues surrounding folic acid fortification initiatives. Prev Nutr Food Sci 19, 247–260.
18. Patel, KR & Sobczyńska-Malefora, A (2017) The adverse effects of an excessive folic acid intake. Eur J Clin Nutr 71, 159–163.
19. Wang, S, Ge, X, Zhu, B et al. (2016) Maternal continuing folic acid supplementation after the first trimester of pregnancy increased the risk of large-for-gestational-age birth: a population-based birth cohort study. Nutrients 8, E493.
20. Keating, E, Correia-Branco, A, Araujo, JR et al. (2015) Excess perigestational folic acid exposure induces metabolic dysfunction in post-natal life. J Endocrinol 224, 245–259.
21. Krishnaveni, GV, Veena, SR, Karat, SC et al. (2014) Association between maternal folate concentrations during pregnancy and insulin resistance in Indian children. Diabetologia 57, 110–121.
22. Yajnik, CS, Deshpande, SS, Jackson, AA et al. (2007) Vitamin B12 and folate concentrations during pregnancy and insulin resistance in the offspring: the Pune Maternal Nutrition Study. Diabetologia 51, 29–38.
23. Valera-Gran, D, García de la Hera, M, Navarrete-Muñoz, EM et al. (2014) Folic acid supplements during pregnancy and child psychomotor development after the first year of life. JAMA Pediatr 168, e142611.
24. Whitrow, MJ, Moore, VM, Rumbold, AR et al. (2009) Effect of supplemental folic acid in pregnancy on childhood asthma: a prospective birth cohort study. Am J Epidemiol 170, 1486–1493.
25. Morton, SMB, Ramke, J, Kinloch, J et al. (2015) Growing Up in New Zealand cohort alignment with all New Zealand births. Aust N Z J Public Health 39, 82–87.
26. Morton, SMB, Atatoa Carr, PE, Grant, CCC et al. (2013) Cohort profile: Growing Up in New Zealand. Int J Epidemiol 42, 65–75.
27. Horsburgh, SC, Malik, M, Pauline, N et al. (2009) Prescribing and Dispensing Data Sources in New Zealand: Their Usage and Future Directions. Dunedin: School of Pharmacy, University of Otago.
28. Ministry of Health (2006) Food and Nutrition Guidelines for Healthy Pregnant and Breastfeeding Women: A Background Paper. Wellington: Ministry of Health.
29. Statistics New Zealand (2009) Final Report of Review of the Official Ethnicity Statistical Standard. Wellington: Statistics New Zealand.
30. World Health Organization (2014) Obesity and Overweight. Fact Sheet no. 311. Geneva: WHO.
31. Brunner Huber, LR (2007) Validity of self-reported height and weight in women of reproductive age. Matern Child Health J 11, 137–144.
32. European Surveillance of Congenital Anomalies (2009) Special Report: Prevention of Neural Tube Defects by Periconceptional Folic Acid Supplementation in Europe. Belfast: EUROCAT.
33. de Walle, HEK & de Jong-van den Berg, LTW (2002) Insufficient folic acid intake in the Netherlands: what about the future? Teratology 66, 40–43.
34. Bartholomew, K, Morton, SMB, Atatoa Carr, PE et al. (2015) Early engagement with a lead maternity carer: results from Growing Up in New Zealand. Aust N Z J Obstet Gynaecol 55, 227–232.
35. Ibrahim, ZM, El-Hamid, SABD, Mikhail, H et al. (2011) Assessment of adherence to iron and folic acid supplementation and prevalence of anemia in pregnant women. Med J Cairo Univ 79, 115–121.
36. Manniën, J, de Jonge, A, Cornel, MC et al. (2014) Factors associated with not using folic acid supplements preconceptionally. Public Health Nutr 17, 2344–2350.
37. Yi, Y, Lindemann, M, Colligs, A et al. (2011) Economic burden of neural tube defects and impact of prevention with folic acid: a literature review. Eur J Pediatr 170, 1391–1400.
38. Girotto, F, Scott, L, Avchalumov, Y et al. (2013) High dose folic acid supplementation of rats alters synaptic transmission and seizure susceptibility in offspring. Sci Rep 3, 1465.
39. Phelan, S (2010) Pregnancy: a ‘teachable moment’ for weight control and obesity prevention. Am J Obstet Gynecol 202, 135.e1–e8.
40. Atkinson, L, Shaw, RL & French, DP (2016) Is pregnancy a teachable moment for diet and physical activity behaviour change? An interpretative phenomenological analysis of the experiences of women during their first pregnancy. Br J Health Psychol 21, 842–858.
41. New Zealand Government (1985) Dietary Supplements Regulations 1985 (SR 1985/208). http://www.legislation.govt.nz/regulation/public/1985/0208/latest/DLM102109.html (accessed May 2017).
44. Hoffman, DJ & Klein, DJ (2012) Growth in transitional countries: the long-term impact of under-nutrition on health. Ann Hum Biol 39, 395–401.
45. Organisation for Economic Co-operation and Development (2015) Health at a Glance 2015: OECD Indicators. Paris: OECD.
46. Williams, J, Mai, CT, Mulinare, J et al. (2015) Updated estimates of neural tube defects prevented by mandatory folic acid fortification – United States, 1995–2011. MMWR Morb Mortal Wkly Rep 64, 1–5.
47. Atta, CAM, Fiest, KM, Frolkis, AD et al. (2016) Global birth prevalence of spina bifida by folic acid fortification status: a systematic review and meta-analysis. Am J Public Health 106, e24–e34.
49. Australian Institute of Health and Welfare (2016) Monitoring the Health Impacts of Mandatory Folic Acid and Iodine Fortification. Canberra: Australian Institute of Health and Welfare.
50. Hilder, L (2016) Neural Tube Defects in Australia, 2007–2011: Before and after Implementation of the Mandatory Folic Acid Fortification Standard. Canberra: Department of Health, Commonwealth of Australia.
51. New Zealand Ministry of Health (2018) Folate Status of Women of Reproductive Age (15–49 Years). From the 2014/15 New Zealand Health Survey. Wellington: Ministry of Health (In the Press).
52. Althubaiti, A (2016) Information bias in health research: definition, pitfalls, and adjustment methods. J Multidiscip Healthc 9, 211–217.
53. Green, T, Newton, R & Bourn, D (2003) Estimated folic acid intakes from simulated fortification of the New Zealand food supply. N Z Med J 116, U294.
54. Evans, SE, Mygind, VL, Peddie, MC et al. (2014) Effect of increasing voluntary folic acid food fortification on dietary folate intakes and adequacy of reproductive-age women in New Zealand. Public Health Nutr 17, 1447–1453.
55. New Zealand Ministry of Health (2003) Improving Folate Intake in New Zealand: Policy Implications. Wellington: Ministry of Health.
56. Bradbury, KE, Williams, SM, Mann, JI et al. (2016) Serum and erythrocyte folate status of New Zealand women of childbearing age following a countrywide voluntary programme by the baking industry to fortify bread with folic acid. Public Health Nutr 19, 2897–2905.
57. Lawrence, M (2005) Assessing the case for mandatory folate fortification: policy-making in the face of scientific uncertainties. Aust N Z J Public Health 29, 328–330.
58. Lawrence, M & Riddell, L (2007) Mandatory fortification with folic acid – what would Hippocrates say? Aust Fam Physician 36, 69–70 72, 75.
59. Lawrence, M (2005) Challenges in translating scientific evidence into mandatory food fortification policy: an antipodean case study of the folate-neural tube defect relationship. Public Health Nutr 8, 1235–1241.