Relation between circulating levels of 25(OH) vitamin D and parathyroid hormone in chronic kidney disease: quest for a threshold. Metzger, Marie; Houillier, Pascal; Gauci, Cédric; Haymann, Jean Philippe; Flamant, Martin; Thervet, Eric; Boffa, Jean-Jacques; Vrtovsnik, François; Froissart, Marc; Stengel, Bénédicte; Ureña-Torres, Pablo; NephroTest Study Group. The Journal of Clinical Endocrinology and Metabolism. 2013; 2922-2928: p.2922-2928. doi:10.1210/jc.2013-1294Article