Prepregnancy and early pregnancy calcium supplementation among women at high risk of pre-eclampsia: a multicentre, double-blind, randomised, placebo-controlled trial

G Justus Hofmeyr, Ana Pilar Betrán, Mandisa Singata-Madliki, Gabriela Cormick, Stephen P Munjanja, Susan Fawcus, Simpiwe Mose, David Hall, Alvaro Ciganda, Armando H Seuc, Theresa A Lawrie, Eduardo Bergel, James M Roberts, Peter von Dadelszen, José M Belizán, and the Calcium and Pre-eclampsia Study Group. Lancet 2019; 393: 330–39