1 2 Bjelakovic, G; Gluud, L. L.; Nikolova, D; Whitfield, K; Wetterslev, J; Simonetti, R. G.; Bjelakovic, M; Gluud, C (2014). "Vitamin D supplementation for prevention of mortality in adults". The Cochrane Database of Systematic Reviews (1): CD007470. doi:10.1002/14651858.CD007470.pub3.