1. McCullough et al.: Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience. The Journal of Steroid Biochemistry and Molecular Biology. Volume 189, May 2019, Pages 228-239
2. Sheila M. O'Byrne and William S. Blaner: Retinol and retinyl esters: biochemistry and physiology. Thematic Review Series: Fat-Soluble Vitamins: Vitamin A. J Lipid Res. 2013 Jul; 54(7): 1731–1743.
3. Myhre et al.: Water-miscible, emulsified, and solid forms of retinol supplements are more toxic than oil-based preparations. The American Journal of Clinical Nutrition, Volume 78, Issue 6, December 2003, Pages 1152–1159
4. Feskanich D et al. Vitamin A intake and hip fractures among postmenopausal women. JAMA, The Journal of the American Medical Association 2002 Jan 2;287(1):47–54,
5. Spiesman IG. Massive doses of vitamins A and D in the prevention of the common cold. Archives of Otolaryngology—Head & Neck Surgery 1941(Oct);34(4):787–791
6. Fu X et al. 9-Cis retinoic acid reduces 1alpha,25-dihydroxycholecalciferol-induced renal calcification by altering vitamin K-dependent gamma-carboxylation of matrix gamma-carboxyglutamic acid protein in A/J male mice. Journal of Nutrition 2008 Dec;138(12):2337–41, https://pmid.us/19022954.
7. Vitamin A on Trial: Does Vitamin A Cause Osteoporosis link: https://www.westonaprice.org/health-topics/abcs-of-nutrition/vitamin-a-on-trial-does-vitamin-a-cause-osteoporosis/
8. Kadri A, Sjahrir H, Juwita Sembiring R, Ichwan M. Combination of vitamin A and D supplementation for ischemic stroke: effects on interleukin-1ß and clinical outcome. Med Glas (Zenica). 2020 Aug 1;17(2):425-432. doi: 10.17392/1137-20. PMID: 32567290. Link: https://pubmed.ncbi.nlm.nih.gov/32567290/
9. Anthony R. Mawson, “Role of Fat-Soluble Vitamins A and D in the Pathogenesis of Influenza: A New Perspective”, International Scholarly Research Notices, vol. 2013, Article ID 246737, 26 pages, 2013. https://doi.org/10.5402/2013/246737 link: Link: https://www.hindawi.com/journals/isrn/2013/246737/
10. Graciela Caire-Juvera, Cheryl Ritenbaugh, Jean Wactawski-Wende, Linda G Snetselaar, Zhao Chen, Vitamin A and retinol intakes and the risk of fractures among participants of the Women’s Health Initiative Observational Study, The American Journal of Clinical Nutrition, Volume 89, Issue 1, January 2009, Pages 323–330, https://doi.org/10.3945/ajcn.2008.26451 Link: https://academic.oup.com/ajcn/article/89/1/323/4598259
11. Ambrosini GL, Bremner AP, Reid A, Mackerras D, Alfonso H, Olsen NJ, Musk AW, de Klerk NH. No dose-dependent increase in fracture risk after long-term exposure to high doses of retinol or beta-carotene. Osteoporos Int. 2013 Apr;24(4):1285-93. doi: 10.1007/s00198-012-2131-6. Epub 2012 Sep 18. PMID: 22986930. Link: https://pubmed.ncbi.nlm.nih.gov/22986930/
12. Russell RM. The vitamin A spectrum: from deficiency to toxicity. Am J Clin Nutr. 2000 Apr;71(4):878-84. doi: 10.1093/ajcn/71.4.878. PMID: 10731492. Link: https://pubmed.ncbi.nlm.nih.gov/10731492/