Table 1

Basic characteristics of included studies
Study Participant characteristics Short description of intervention Total folate intake*(μg/day) Mean duration of intervention** Health outcomes
Country Age No. in intervention and control groups
Baumslag 1970 [25] South Africa N/A 65; 63a and 62; 52b 200 mg iron + 5 mg FA/day 8620a; 8747b 16 wka and 12 wkb birth weight
200 mg iron/day 120a; 247b
Iyengar 1971 [26] India N/A 23; 26 60 mg iron + 300 μg FA/day 757 18 wk birth weight
60 mg iron/day 247
Iyengar 1975 [27] India N/A 98; 91 60 mg iron + 500 μg FA/day 1097 16 wk birth weight; placental weight
60 mg iron/day 247
Klingler 2006 [24] Spain 18-40 y 16; 12 400 μg 5-MTHF/day 647 20 wk birth weight; placental weight; length of gestation
11; 16 placebo/day 247
fish oil + 400 μg 5- MTHF/day 647
fish oil/day 247
Lira 1989 [19] Chile 26.8±4.3 y 26.6±5.3 y 75; 78 105 mg iron + 350 μg FA/day 842 24 wk length of gestation
105 mg iron/day 247
Nogueira 2002 [23] Brasil 13-18 y 15; 13 120 mg iron sulphate + 250 μg FA/day 545 22 wk birth weight; length of gestation
120 mg iron sulphate/day 120
Rolschau 1979 [33] Denmark N/A 20; 16 250 mg ferrofumarate + 5 mg FA/day 8747 17 wk birth weight; placental weight; length of gestation
250 mg ferrofumarate/day 247
Tchernia 1982 [28] France N/A 54; 54 iron + μg FA/day 842 12 wk birth weight; placental weight; length of gestation
iron/day 247

Abbreviations: a, data of Bantu women; b, data of White women; FA, folic acid; 5-MTHF, 5-methyltetrahydrofolate; N/A, data not available; *, expressed as Dietary Folate Equivalents; **, supplements were administered from the second trimester to delivery in each study.

Fekete et al.

Fekete et al. Nutrition Journal 2012 11:75   doi:10.1186/1475-2891-11-75

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