References
- Tilman Grune, Georg Lietz, Andreu Palou, A. Catharine Ross, Wilhelm Stahl, Guangweng Tang, David Thurnham, Shi-an Yin, Hans K. Biesalski: β-Carotene Is an Important Vitamin A Source for Humans; J Nutr. 2010 Dec; 140(12): 2268S–2285S.; Published online 2010 Oct 27.; doi: 10.3945/jn.109.119024; PMCID: PMC3139236
- Vitamin A and Carotenoids Fact Sheet for Health Professionals
- Colorado State University Extension, L. Bellows and R. Moore: Fat-Soluble Vitamins: A, D, E, and K – 9,315; accessed on July 11, 2016
- Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. 4, Vitamin A.