Table. Characteristics of Included Randomized Clinical Trials.
Source | Country | Total Sample Size | Participants | Initiation and Timing of Supplementation | Interventions | Outcomes |
---|---|---|---|---|---|---|
Brooke et al,12 1980 | United Kingdom | 126 | Pregnant Asian women | Third trimester | Ergocalciferol, 1000 IU/d, vs placebo | Cord blood 25(OH)D concentration, neonatal anthropometry, SGA, LBW, gestational age at birth, anthropometry at birth, 3, 6, 9, and 12 mo |
Chawes et al,13 2016 | Denmark | 623 | Pregnant women not after wk 26; without endocrine, cardiovascular, or nephrologic disorders; vitamin D3 intake no more than 600 IU/d | 24 wk of gestation to 1 wk postpartum | Cholecalciferol, 2800 IU/d, vs 400 IU/d | Fetal or neonatal death, congenital malformation, admission to a NICU, preterm birth, wheeze, asthma, upper and lower respiratory tract infections, eczema, allergy skin prick test, allergy-specific IgE at age 3 y |
Cooper et al,14 2016 | United Kingdom | 965 | Pregnant women >18 y, singleton pregnancy, gestation <17 weeks, serum 25(OHD) level 10-40 ng/mL at 10-17 wk of gestation | 14 wk of gestation or as soon as possible before 17 wk of gestation if recruited later until delivery | Cholecalciferol, 1000 IU/d, vs placebo | Fetal or neonatal death, congenital malformation, neonatal anthropometry, preterm birth |
Dawodu et al,15 2013 | United States | 126 | Arab expectant mothers, 12-16 wk of gestation, singleton pregnancy | 12-16 wk of gestation until delivery | Cholecalciferol, 2000 or 4000 IU/d, vs 400 IU/d | Cord blood 25(OH)D concentration, SGA |
Delvin et al,16 1986 | France | 30 | Pregnant women | Third trimester | Cholecalciferol, 1000 IU/d, vs no treatment | Cord blood 25(OH)D concentration |
Goldring et al,17 2013; Yu et al,36 2009 | United Kingdom | 179 | Pregnant women | 27 wk of gestation until delivery | Ergocalciferol, 800 IU/d, or cholecalciferol, 200 000 IU (1 dose), vs no treatment (control) | Fetal or neonatal death, cord blood 25(OH)D concentration, neonatal anthropometry, SGA, gestational age at birth, wheeze, eczema, upper and lower respiratory tract infections at age 3 y |
Grant et al,18 2014 | New Zealand | 258 | Pregnant women, 26-30 wk of gestation, singleton pregnancy, no vitamin D supplementation >200 IU/d, history of renal stones, hypercalcemia, or any serious pregnancy complication at enrollment | 27 wk of gestation until delivery | Cholecalciferol, 1000 or 2000 IU/d, vs placebo | Fetal or neonatal death, cord blood 25(OH)D concentration, preterm birth, asthma, upper and lower respiratory tract infections, allergy skin prick test, allergy-specific IgE at age 3 y |
Hashemipour et al,19 2014 | Iran | 110 | Iranian pregnant women with vitamin D deficiency | Start at 26-28 wk of gestation; duration, 8 wk | Cholecalciferol, 50 000 IU/wk, vs 400 IU/d | Fetal or neonatal death, cord blood 25(OH)D concentration, neonatal anthropometry, SGA, preterm birth |
Hollis et al,20 2011 | United States | 350 | Women with a singleton pregnancy | 12-16 wk of gestation until delivery | Cholecalciferol, 2000 or 4000 IU/d, vs 400 IU/d | Fetal or neonatal death, admission to a NICU, cord blood 25(OH)D concentration, neonatal anthropometry, gestational age at birth |
Hossain et al,21 2014 | Pakistan | 175 | Women with singleton pregnancy | 20 wk of gestation until delivery | Cholecalciferol, 4000 IU/d, vs routine care | Fetal or neonatal death, Apgar score, cord blood 25(OH)D concentration, neonatal anthropometry, SGA, gestational age at birth, preterm birth |
Kalra et al,22 2012 | Zimbabwe | 109 | Pregnant women | 12-24 wk of gestation until delivery | Cholecalciferol, 120 000 IU (1 dose) or 60 000 IU (2 doses), vs standard care | Neonatal anthropometry, infant anthropometry at 3, 6, and 9 mo |
Karamali et al,23 2015 | Iran | 60 | Pregnant women prima gravida, aged 18-40 y, at risk for preeclampsia, without abnormal fetal anomaly scan | 20-30 wk of gestation | Cholecalciferol, 50 000 IU/fortnight, vs placebo | Apgar score, neonatal anthropometry, LBW, gestational age at birth, preterm birth |
Litonjua et al,24 2016 | United States | 835 | Pregnant women aged 18-39 y; gestational age 10-18 wk; history of asthma, eczema, or allergic rhinitis; nonsmoker; English or Spanish speaking | 10-18 wk of gestation until delivery | Cholecalciferol, 4400 vs 400 IU/d | Fetal or neonatal death, congenital malformation, admission to a NICU, cord blood 25(OH)D concentration, neonatal anthropometry, preterm birth, asthma, lower respiratory tract infections, eczema, allergy skin prick test, allergy-specific IgE at age 3 y |
Mallet et al,25 1986 | France | 77 | White pregnant women | 7 mo of gestation | Ergocalciferol, 1000 IU/d or 200 000 IU (1 dose), vs control | Cord blood 25(OH)D concentration |
March et al,26 2015 | Canada | 105 | Pregnant women aged 18-45 y, healthy, 13-24 wk of gestation, exclusion of women receiving supplements >400 IU/d | 13-24 wk of gestation until delivery | Cholecalciferol, 1000 or 2000 IU/d, vs 400 IU/d | Cord blood 25(OH)D concentration |
Marya et al,27 1988 | India | 200 | Pregnant women aged 22-35 y | 7 mo of gestation | Cholecalciferol, 600 000 IU (2 doses), vs no supplementation | Neonatal anthropometry, LBW, gestational age at birth |
Mojibian et al,28 2015 | Iran | 389 | Pregnant women, 12-16 wk of gestation, serum 25(OH)D <30 ng/mL | 12 wk of gestation until delivery | Cholecalciferol, 50 000 IU/fortnight, vs 400 IU/d | Apgar score, cord blood 25(OH)D concentration, neonatal anthropometry, LBW, preterm birth |
Rodda et al,29 2015 | Australia | 45 | Pregnant women, singleton pregnancy, serum 25(OH)D <30 ng/mL | 12-16 wk of gestation until delivery | Cholecalciferol, 2000 IU/d (adjusted to 4000 IU/d if serum vitamin D level remains <75 nmol/L), vs standard care | Cord blood 25(OH)D concentration |
Roth et al,30 2013 | United States | 147 | Pregnant women | Third trimester | Cholecalciferol, 35 000 IU/wk, vs placebo | Fetal or neonatal death, 25(OH)D concentration, neonatal anthropometry, gestational age at birth, preterm birth, infant anthropometry at 12 mo, weight, length, and head circumference z scores in infants at age 1 y |
Sablok et al,31 2015 | India | 165 | Prima gravida with singleton pregnancy at 14-20 wk, without preexisting osteomalacia, known hyperparathyroidism, renal or liver dysfunction, tuberculosis, or sarcoidosis | 20 wk of gestation until delivery | Cholecalciferol, 60 000 IU (1 dose), 120 000 IU (2 doses), or 120 000 IU (4 doses), vs no supplementation | Cord blood 25(OH)D concentration, neonatal anthropometry, SGA, preterm birth |
Sahoo et al,32 2017 | India | 52 | Pregnant women aged >18 y, singleton pregnancy, <20 wk of gestation, no known bone diseases or complicated pregnancy, no vitamin D supplementation within previous 3 mo | 14-20 wk of gestation until delivery | Cholecalciferol, 60 000 IU/4 wk or 60 000 IU/8 wk, vs 400 IU/d | Cord blood 25(OH)D concentration, neonatal anthropometry, weight, length, and head circumference z scores in infants at age 1 y |
Yap et al,33 2014 | Australia | 179 | Women with singleton pregnancies, aged ≥18 y and gestational age <20 wk, no history of diabetes, calcium or vitamin D metabolism disorders, hypercalcemia, or significant renal impairment, no vitamin D supplements ≥1000 IU/d | 20 wk of gestation until delivery | Cholecalciferol, 5000 IU/d, vs 400 IU/d | Fetal or neonatal death, cord blood 25(OH)D concentration, neonatal anthropometry, gestational age at birth, preterm birth |
Yesiltepe Mutlu et al,34 2014 | Turkey | 51 | Pregnant women aged >16 y, singleton pregnancy, no previously known calcium metabolism or untreated thyroid disorders | 13-32 wk of gestation until delivery | Cholecalciferol, 1200 or 2000 IU/d, vs 600 IU/d | Neonatal anthropometry, neonatal 25(OH)D concentration |
Zerofsky et al,35 2016 | United States | 49 | Participants aged >18 y with a singleton pregnancy <20 wk | No later than 20 wk of gestation until delivery | Cholecalciferol, 2000 IU/d, vs 400 IU/d | Apgar score, neonatal anthropometry, gestational age at birth |
Abbreviations: IgE, immunoglobulin E; LBW, low birth weight; NICU, neonatal intensive care unit; RCT, randomized clinical trial; SGA, small for gestational age; 25(OH)D, 25-hydroxyvitamin D.
SI conversion factor: To convert 25(OH)D to nanomoles per liter, multiply by 2.496.