(Abstracted from BMJ 2018;361:k2167)
Observational studies have found that women with lower levels of 25-hydroxyvitamin D are at greater risk of preeclampsia. Although some small trials of vitamin D supplementation in pregnancy have suggested a potential benefit of supplementation, a recent meta-analysis found no impact on preeclampsia from vitamin D supplementation.
Medical Research Council Integrative Epidemiology Unit, University of Bristol (M.C.M., D.A.L., C.B., A.F.); Department of Population Health Sciences, Bristol Medical School (M.C.M., D.A.L., C.B., A.F.), Bristol, United Kingdom; Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway (M.C.M., P.M.); Generation R Study Group (K.M., J.F.F., V.W.V.J., F.R.), Department of Pediatrics (K.M., J.F.F., V.W.V.J.), and Department of Epidemiology (K.M., J.F.F., V.W.V.J., F.R.), Erasmus MC, University Medical Centre Rotterdam, Rotterdam, the Netherlands; Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC (A.B., S.M.E.); National Institute for Health Research Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust, and University of Bristol, Bristol, United Kingdom (D.A.L., A.F.); Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC (S.J.L.); Sanger Institute, University of Cambridge, Cambridge, United Kingdom (R.M., N.W.); Division for Mental and Physical Health, Norwegian Institute of Public Health (W.N., C.M.P., L.C.S., G.T.); Oslo Centre for Biostatistics and Epidemiology, Oslo University Hospital (C.M.P.), Oslo, Norway; Department of Internal Medicine, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, the Netherlands (F.R.); and Departamento de Medicina Preventiva, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil (C.B.)