39.Bosomworth NJ. Mitigating epidemic vitamin D deficiency: The agony of evidence. Can Fam Physician. 2011 Jan;57(1):16-20. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024150/
40.Holick MF. Evidence-based D-bate on health benefits of vitamin D revisited. Dermatoendocrin. 2012;4(2):183-190. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427198/
41.Schönlau F, Rohdewald P. Pycnogenol for diabetic retinopathy. A review. Int Ophthalmol. 2001;24(3):161-71. http://www.ncbi.nlm.nih.gov/pubmed/12498513
42.Greco AV, Mingrone G, Bianchi M, et al. Effect of propionyl-L-carnitine in the treatment of diabetic angiopathy: Controlled double blind trial versus placebo. Drugs Exp Clin Res. 1992;18(2):69-80. http://www.ncbi.nlm.nih.gov/pubmed/1644013