Vitamin A

Vitamin A (Retinol, Retinoic Acid, Retinal) is an essential fat-soluble vitamin. Good animal food sources of vitamin A include: beef liver, cod liver oil, salmon, and dairy products or fortified milk. Vitamins A can also be found in orange, yellow, and green fruits and vegetables including: cantaloupe, apricots, broccoli, carrots, squash, and cereals.1  

The 100% Daily Value for Vitamin A (based on a 2,000 kcal diet) is 5,000 International Units (IU) (1,500 µg Retinol Activity Equivalent (RAE)),but it has been revised to 900 µg as of May 27, 2016.13 The 100% Daily Value for pregnant or lactating women is 1300 μg, effective as of July 26, 2018.13

Forms

  • Alpha-carotene/Palm Oil Carotenes: Palm carotene is a suspension of natural mixed carotenoids extracted and purified from the fruit of the red palm (Elaeis guineensis). It contains a naturally occurring mixture of carotenoids, predominantly alpha-carotene and beta-carotene, which are precursors of vitamin A. Palm oil from the fruit of the palm is physically and chemically different from palm kernel oil, which is derived from the seed, and from coconut oil. Carotenoids are extracted from the crude palm oil, and then concentrated, purified, standardized, and suspended in vegetable oil.
  • Beta-carotene: Beta-carotene (pro-vitamin A) is a natural yellow-orange pigment found in many plant foods. When needed, the body converts beta-carotene to vitamin A. When not needed, beta-carotene is safely stored in body tissues where it functions as an antioxidant.3, 4
  • Beta-Cryptoxanthin: Cryptoxanthin (pro-vitamin A) is a natural carotenoid pigment that can be found in oranges, papayas, butter, and egg yolk. Beta Cryptoxanthin is known to be a powerful antioxidant.5
  • Vitamin A Acetate/Vitamin A Palmitate: Vitamin A acetate and vitamin A palmitate are two bioavailable forms of vitamin A. Vitamin A acetate is constructed from beta-ionone and the organic acid, acetic acid. Vitamin A palmitate is made by combining vitamin A acetate with the fatty acid, palmitic acid.

Major Health Benefits

Vitamin A is required for healthy skin, skeletal development, normal vision, normal fetal development, and healthy mucous membranes. Vitamin A is important for the immune system to function normally because it plays an important role in white blood cell (e.g., lymphocytes) division (differentiation). Adequate intake of vitamin A has been found to help prevent night blindness and protect the cornea.6 Vitamin A also prevents the hardening (keratinization) of skin and may prevent the developing autoimmune disorders.7,8

Cautions

The recommended maximum amount of Vitamin A consumed in one day should not exceed 10,000 IU (3,000 µg RAE/day).9 Excessive chronic intake of Vitamin A can lead to nausea, vomiting, and headache, and chronic high levels of Vitamin A in the blood may cause dry itchy skin, flaky skin (desquamation), and joint pain.10,11 Excessive consumption of Vitamin A and Beta-carotene supplements may increase the risk of lung cancer, death from lung cancer, and cardiovascular disease in current or former smokers.12

References

  1. National Institutes of Health. Vitamin A. Office of Dietary Supplements. 2013 June. http://ods.od.nih.gov/factsheets/VitaminA-Consumer/ (Accessed Dec. 21, 2016)
  2. US Food and Drug Administration. Guidance for Industry: A Food Labeling Guide (14. Appendix F: Calculate the Percent Daily Value for the Appropriate Nutrients). US Department of Health and Human Services. 2013 January. http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/LabelingNutrition/ucm064928.htm
  3. Wassef L, Shete V, Costabile B, Rodas R, Quadro L. High Preformed Vitamin A Intake during Pregnancy Prevents Embryonic Accumulation of Intact β-Carotene from the Maternal Circulation in Mice. J Nutr. 2015 May 20. PMID: 25995275.
  4. Sommerburg O, De Spirt S, Mattern A, et al. Supplementation with red palm oil increases β-carotene and vitamin A blood levels in patients with cystic fibrosis. Mediators Inflamm. 2015;2015:817127. PMID: 25688177; PMCID: PMC4321850.
  5. ChEBI Ontology. Beta Cryptoxanthin. ChEBI. http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:10362
  6. Lanska DJ. Chapter 29: historical aspects of the major neurological vitamin deficiency disorders: overview and fat-soluble vitamin A. Handb Clin Neurol. 2010;95:435-44. PMID: 19892132.
  7. Green HN, Mellanby E. Vitamin A as an anti-infective agent. Br Med J. 1928:2 (3537): 691-696.
  8. Jafarirad S, Siassi F, Harirchian MH, Amani R, Bitarafan S, Saboor-Yaraghi A. The effect of vitamin a supplementation on biochemical parameters in multiple sclerosis patients. Iran Red Crescent Med J. 2013 Mar;15(3):194-8. doi: 10.5812/ircmj.3480. Epub 2013 Mar 5. PubMed PMID: 23983997; PubMed Central PMCID: PMC3745746.
  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. The National Academic Press. 2001. http://www.nap.edu/catalog/10026/dietary-reference-intakes-for-vitamin-a-vitamin-k-arsenic-boron-chromium-copper-iodine-iron-manganese-molybdenum-nickel-silicon-vanadium-and-zinc (pp. 82)
  10. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. The National Academic Press. 2001. (pp. 125)
  11. Higdon, J. Vitamin A. Linus Pauling Institute, Oregon State University. 2000. (Reviewed in 2015 by Tan, L.) (Safety)
  12. Goodman GE, Thornquist MD, Balmes J, Cullen MR, Meyskens FL Jr, Omenn GS, Valanis B, Williams JH Jr. The Beta-Carotene and Retinol Efficacy Trial: incidence of lung cancer and cardiovascular disease mortality during 6-year follow-up after stopping beta-carotene and retinol supplements. J Natl Cancer Inst. 2004 Dec 1;96(23):1743-50. PubMed PMID: 15572756.
  13. US Food and Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels. US Department of Health and Human Services. Federal Register / Vol. 81, No. 103, p. 33982 / May 27, 2016. https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf