1. Vitamin D2 is much less effective than vitamin D3 in humans;Armas;J Clin Endocrinol Metab,2004
2. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers and cardiovascular disease;Holick;Am J Clin Nutr,2004
3. The mechanisms of vitamin D toxicity;Reinfold;Bone Miner,1990
4. Role in the calcium economy;Heaney,2005
5. Steinmeyer A, Kirsch G, Neef G, Schwarz K, Thieroff-Ekerdt R, Wiesinger H, et al. Vitamin D derivatives with carbo- or heterocyclic substituents at C-25, a process for their production, intermediate products and their use for producing medicaments. US Patent 6,600,058; 2003.