The association between vitamin D and FEV1 in a general population is not explained by eNO
Willemien Thijs, Robert Prein, Frits R. Rosendaal, Saskia Middeldorp, Klaus F. Rabe, Martin den Heijer, Saskia le Cessie, Pieter S. Hiemstra, Renee de Mutsert
European Respiratory Journal Sep 2013, 42 (Suppl 57) P1559;