Vitamin A (Beta-Carotene)
Description
Two main constituents of Vitamin A can be found in food: preformed retinol and carotenoids.
Carotenoids constitute a large class of antioxidants, which help protect the body against the effect of free radicals. Over 600 different carotenoids have been identified; among those, beta-carotene is probably the best known. In addition to its antioxidative properties, beta-carotene has pro-vitamin A activities, meaning that the body converts beta-carotene into vitamin A. Some other carotenoids of importance are lycopene, lutein and zeaxanthin.
Function
Vitamin A is essential for the normal function of the retina and vision, especially in dim light. It is also essential for maintaining the integrity of the epithelial tissues, the immune system, bone development and growth.
Additionally, epidemiological studies support long-term beneficial effects of beta-carotene intake on a number of degenerative diseases. Epidemiological evidence also suggests that long-term intake of dietary beta-carotene may reduce the risk of several types of cancer. Similar findings show that it also has positive effects on heart disease and immune health.
Deficiency
Vitamin A deficiency may lead to severe skin and eye lesions as well as reduced resistance to infection. Vitamin A deficiency is the leading cause of preventable blindness in the world.
Sources
Retinol is usually found in fish oils and liver. Beta- carotene and other provitamin A carotenoids are abundant in carrots, broccoli, yellow squash, corn, tomatoes, papayas, oranges, and dark green leafy vegetables like spinach and Chinese cabbage.
Toxicity
Although ingestion of too much preformed vitamin A (retinol) can be toxic, excessive intake of beta-carotene may lead to yellowing of the skin but is not known to induce vitamin A toxicity.
Excessive intake of preformed vitamin A has been associated with liver toxicity, hypercalcemia, headaches, “pseudotumor cerebri” (characterized by symptoms mimicking those of a brain tumour and caused by an increased of intracranial pressure), and foetal anomalies.
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Scientific References
Books
Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc, Institute of Medicine. Food and Nutrition Board, National Academy Press, Washington, DC, 2001.
Impact of vitamin A on immunity and infection in developing countries, Semba RD., In: Preventive Nutrition: The Comprehensive Guide for Health Professionals. 2nd ed., Bendich A, Decklebaum RJ, eds., Totowa: Humana Press Inc; 2001:329-346.
Preventive Nutrition: The Comprehensive Guide for Health Professionals. 2nd ed., Adrianne Bendich (Editor), Richard J., M.D. Deckelbaum (Editor), Joann E., M.D. Manson (Foreword), Frank B., Ph.D. Hu (Foreword), Totowa: Humana Press Inc; 2001:97-129.
Preventive nutrition and lung cancer, Comstock GW, Helzlsouer KJ., In: Preventive Nutrition: The Comprehensive Guide for Health Professionals, Adrianne Bendich and Richard J. Deckelbaum, Humana Press, Totowa, NJ, 1997, pp.109-134
Vitamin A and retinoids. 9th Edition, Ross AC., In: Modern Nutrition in Health and Disease, Shils ME, Olson J, Shike M, Ross AC, Lippincott Williams and Wilkins, New York, 1999, pp. 305-27.
Scientific Articles
A randomized controlled trial to assess sunscreen application and beta carotene supplementation in the prevention of solar keratoses, Steven Darlington, BSc; Gail Williams, PhD; Rachel Neale, PhD; Christine Frost, MB, BS, PhD; Adèle Green, MB, BS, PhD, Archives of Dermatology, 2003;139:451-455.
A randomized trial of beta carotene supplementation and cognitive function in men: the Physicians' Health Study II., Grodstein F, Kang JH, Glynn RJ, Cook NR, Gaziano JM., Archives of Internal Medicine, 2007 Nov 12;167(20):2184-90.
A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa, Eliot L. Berson, MD; Bernard Rosner, PhD; Michael A. Sandberg, PhD; K. C. Hayes, DVM, PhD; Britain W. Nicholson, MD; Carol Weigel-DiFranco; Walter Willett, MD, Archives of Ophthalmology, 1993;111(6):761-772.
[Abstract]
Alcohol, vitamin A, and beta-carotene: adverse interactions, including hepatotoxicity and carcinogenicity, Leo MA, Lieber CS., American Journal of Clinical Nutrition, 1999;69(6):1071-1085.
Antioxidants in health and disease: Overview, Olson JA, Kobayashi S., Proceedings of the Society for Experimental Biology and Medicine, 1992;200:245-7.
[Abstract]
Benefits and liabilities of vitamin A and carotenoids, Olson J A., Journal of Nutrition, 1996;126:1208S-12S.
Beta carotene supplementation and age-related maculopathy in a randomized trial of US physicians, Christen WG, Manson JE, Glynn RJ, et al., Archives of Ophthalmology, 2007 Mar;125(3):333-9.
Beta carotene: from biochemistry to clinical trials, Pryor WA, Stahl W, Rock CL., Nutrition Reviews, 2000;58:39-53.
[Abstract]
Beta-carotene and other carotenoids as antioxidants, Pavia SA, Russell RM., Journal of the American College of Nutrition, 1999;18:426-33.
Biological actions of carotenoids, Bendich A, Olson JA., FASEB Journal, 1989:3;1927-32
Bone resorption activity of all-trans retinoic acid is independent of vitamin D in rats, Rohde CM, DeLuca H., Journal of Nutrition, 2003;133(3):777-783.
Carotenoids and retinoids: A review of research, clinical, and public health applications, Hinds TS, West WL, Knight EM., The Journal of Clinical Pharmacology, 1997;37:551-8.
[Abstract]
Carotenoids, alpha-tocopherols, and retinol in plasma and breast cancer risk in northern Sweden, Hulten K, Van Kappel AL, Winkvist A, et al., Cancer Causes & Control, 2001;12(6):529-537.
[Abstract]
Dietary antioxidant vitamins, retinol, and breast cancer incidence in a cohort of Swedish women, Michels KB, Holmberg L, Bergkvist L, Ljung H, Bruce A, Wolk A., International Journal of Cancer, 2001;91(4):563-567.
Dietary carotenoids and their role in combating vitamin A deficiency: A review of the literature, de Pee S, West CE., European Journal of Clinical Nutrition, 1996 Jul;50 Suppl 3:S38-53.
[Abstract]
Dietary carotenoids and vitamins A, C, and E and risk of breast cancer, Zhang S, Hunter DJ, Forman MR, et al., Journal of the National Cancer Institute, 1999;91(6):547-556.
Dietary Intake of Macronutrients, Micronutrients, and Other Dietary Constituents: United States 1988-94, Bialostosky K, Wright JD, Kennedy-Stephenson J, McDowell M, Johnson CL., Vital and Health Statistics, 2002;11(245):6-99. US
[Abstract]
Effect of vitamin E and beta carotene on the incidence of angina pectoris. A randomized, double-blind, controlled trial, Rapola JM, Virtamo J, Haukka JK, et al., JAMA, 1996;275(9):693-698.
Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease, Omenn GS, Goodman GE, Thornquist MD, et al., The New England Journal of Medicine, 1996;334(18):1150-1155.
Intake of carrots, spinach, and supplements containing vitamin A in relation to risk of breast cancer, Longnecker MP, Newcomb PA, Mittendorf R, Greenberg ER, Willett WC., Cancer Epidemiology, Biomarkers & Prevention, 1997;6(11):887-892.
Interactions between zinc and vitamin A: an update, Christian P, West KP, Jr., American Journal of Clinical Nutrition, 1998;68(2 Suppl):435S-441S.
Maternal vitamin A deficiency and mother-to-child transmission of HIV-1, Ramasethu J. Semba RD, et al., Lancet, 1994 Jun 25;343(8913):1593-7.
[Abstract]
Measles severity and serum retinol (vitamin A) concentration among children in the United States, Butler JC, Havens PL, Sowell AL, Huff DL, Peterson DE, Day SE, Chusid MJ, Benning RA, Circo R, Davis JP., Pediatrics, 1993;91:1176-81.
[Abstract]
Micronutrients and breast cancer, Franceschi S., European Journal of Cancer Prevention, 1997;6(6):535-539.
[Abstract]
MRC/BHF Heart Protection Study of antioxidant vitamin supplementation in 20,536 high-risk individuals: a randomised placebo-controlled trial, Heart Protection Study Collaborative Group, Lancet, 2002;360(9326):23-33.
[Abstract]
Neoplastic and antineoplastic effects of beta-carotene on colorectal adenoma recurrence: results of a randomized trial, Baron JA, Cole BF, Mott L, et al., Journal of the National Cancer Institute, 2003;95(10):717-722.
No effect of vitamin A intake on bone mineral density and fracture risk in perimenopausal women, Rejnmark L, Vestergaard P, Charles P, et al., Osteoporosis International, 2004;15(11):872-880.
[Abstract]
Nutrients and their role in host resistance to infection, Field CJ, Johnson IR, Schley PD., Journal of Leukocyte Biology, 2002;71(1):16-32.
Nutrition and immunity with emphasis on infection and autoimmune disease, Harbige LS., Nutrition Journal, 1996;10:285-312.
[Abstract]
Optimal nutrition: vitamin A and the carotenoids, Thurnham DI, Northrop-Clewes CA, Proceedings of the Nutrition Society, 1999;58(2):449-457.
Osteoporosis prevention, diagnosis, and therapy, National Institutes of Health, USA, NIH Consensus Statement, 2000 March 27-29, 2000:1-36.
[Abstract]
Protective dietary factors and lung cancer, Fontham ETH., International Journal of Epidemiology, 1990;19:S32-S42.
[Abstract]
Relationships of serum carotenoids, retinol, alpha-tocopherol, and selenium with breast cancer risk: results from a prospective study in Columbia, Missouri (United States), Dorgan JF, Sowell A, Swanson CA, et al., Cancer Causes & Control, 1998;9(1):89-97.
[Abstract]
Retinitis pigmentosa: defined from a molecular point of view, van Soest S, Westerveld A, de Jong PT, Bleeker-Wagemakers EM, Bergen AA., Survey of Ophthalmology , 1999;43(4):321-334.
Retinoids and the skin, Futoryan T, Gilchrest BE., Nutrition Reviews, 1994;52:299-310.
[Abstract]
Retinoids, carotenoids, and human breast cancer cell cultures: a review of differential effects, Prakash P, Krinsky NI, Russell RM., Nutrition Reviews, 2000;58(6):170-176.
[Abstract]
Retinol intake and bone mineral density in the elderly: the Rancho Bernardo Study, Promislow JH, Goodman-Gruen D, Slymen DJ, Barrett-Connor E., Journal of Bone and Mineral Research, 2002;17(8):1349-1358.
Retinol, supplemental vitamin A and bone status, Sowers MF, Wallace RB., Journal of Clinical Epidemiology, 1990;43(7):693-699.
[Abstract]
The role of vitamin A and related retinoids in immune function, Semba RD., Nutrition Reviews, 1998;56:S38-48.
[Abstract]
Safety of <7500 RE (<25000 IU) vitamin A daily in adults with retinitis pigmentosa, Sibulesky L, Hayes KC, Pronczuk A, Weigel-DiFranco C, Rosner B, Berson EL., American Journal of Clinical Nutrition, 1999;69(4):656-663.
Serum levels of micronutrients, antioxidants and total antioxidant status predict risk of breast cancer in a case control study, Ching S, Ingram D, Hahnel R, Beilby J, Rossi E., Journal of Nutrition, 2002;132(2):303-306.
Serum retinol levels and the risk of fracture, Michaelsson K, Lithell H, Vessby B, Melhus H., New England Journal of Medicine, 2003;348(4):287-294.
Subclinical vitamin A deficiency: A potentially unrecognized problem in the United States, Stephens D, Jackson PL, Gutierrez Y., Pediatric Nursing, 1996;22:377-89.
[Abstract]
Supplementation with vitamin A and iron for nutritional anaemia in pregnant women in West Java, Indonesia, Suharno D, West CE, Muhilal, Karyadi D, Hautvast JG., Lancet, 1993;342(8883):1325-1328.
[Abstract]
The acute and chronic toxic effects of vitamin A, Penniston KL, Tanumihardjo SA., American Journal of Clinical Nutrition, 2006;83(2):191-201.
The contribution of vitamin A to public health, Underwood BA, Arthur P., FASEB Journal 1996;10(9):1040-1048.
The effect of vitamin A on epithelial integrity, McCullough, F. et al., Proceedings of the Nutrition Society, 1999; volume 58: pages 289-293.
The function of vitamin A in cellular growth and differentiation, and its roles during pregnancy and lactation, Ross AC, Gardner EM., Advances in Experimental Medicine and Biology, 1994;352:187-200.
[Abstract]
The role of vitamin A and related retinoids in immune function, Semba RD., Nutrition Reviews, 1998;56(1 Pt 2):S38-48.
The vitamin A spectrum: from deficiency to toxicity, Russell RM., American Journal of Clinical Nutrition, 2000;71(4):878-884.
Vitamin A and human immunodeficiency virus infection, Semba RD., Proceedings of the Nutrition Society, 1997;56(1B):459-469.
Vitamin A and public health: Challenges for the next decade, Ross DA., Proceedings of the Nutrition Society, 1998;57:159-65.
Vitamin A and retinoids in antiviral responses, Ross AC, Stephensen CB., FASEB Journal, 1996;10:979-85.
Vitamin A antagonizes calcium response to vitamin D in man, Johansson S, Melhus H., Journal of Bone and Mineral Research, 2001;16(10):1899-1905.
Vitamin A status: Relationship to immunity and the antibody, Ross AC., Proceedings of the Society for Experimental Biology and Medicine, 1992;200:303-20.
[Abstract]
Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection, Wiysonge CS, Shey MS, Sterne JA, Brocklehurst P., Cochrane Database Systematic Reviews, 2005;(4):CD003648.
[Abstract]
Vitamin A treatment of measles,Committee on Infectious Diseases, Pediatrics, 1993;91:1014-5.
[Abstract]
Vitamin A-functions, dietary requirements and safety in humans, Gerster H., International Journal for Vitamin and Nutrition Research, 1997;67:71-90.
[Abstract]
Vitamin and mineral supplements, Hamrick I, Counts SH., Primary Care, December 2008:35(4);729-747.
[Abstract]
Vitamin E and beta carotene supplementation in high risk for stroke: a subgroup analysis of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, Leppala JM, Virtamo J, Fogelholm R, et al., Archives of Neurology, 2000;57(10):1503-1509.
Vitamins A, C and E and the risk of breast cancer: results from a case-control study in Greece, Bohlke K, Spiegelman D, Trichopoulou A, Katsouyanni K, Trichopoulos D., British Journal of Cancer, 1999;79(1):23-29.
