Prickly Pears

Prickly Pears (Opuntia ficus-indica) aka: Nopal, Nopales, Barberry Figs, and Indian Figs, are cylindrical shaped fruits with a thorny outer skin, firm to mushy inner flesh, and many small seeds at their center. Prickly Pears come in a variety of colors and can be red, green, yellow, or purple.

Health Benefits of Prickly Pears

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How to choose Prickly Pears

Look for vibrantly colored prickly pears that yield lightly to pressure, avoid any pears that are too mushy, or wrinkled.

Climate and origin

Prickly Pears originated in the Americas and can now be found in almost every hot dry climate across the world.


Prickly pears have a subtle sweet taste that is lightly fragrant. They have a firm to mushy texture, and there are many seeds in the middle to contend with. It is important not to eat any of the skin of a prickly pear due to thorns and glochids which can cause a lot of discomfort.

Miscellaneous information

Prickly pears can be found distilled into the form of alcoholic beverages, most notably Bajtra Liqueur and Tungi Spirit.

Natural vitamins, minerals, and nutrients found in Prickly Pears + Complete Nutrition Facts

Vitamin C | Calcium | Dietary Fiber | Magnesium | Potassium |

Click here to compare these nutrition facts with other fruits.
Nutrition Facts
Prickly pears raw             
Serving Size 100g
Calories 41
% Daily Value*
Total Fat 0.51g1%
    Saturated Fat 0.067g0%
Cholesterol 0mg~%
Sodium 5mg0%
Total Carbohydrate 9.6g3%
    Dietary Fiber 3.6g14%
    Sugar ~g~
Protein 0.7g~
Vitamin A1%Vitamin C23%
*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Vitamins  %DV
Vitamin A 43IU1%
    Retinol equivalents 2μg~
    Retinol 0μg~
    Alpha-carotene 0μg~
    Beta-carotene 25μg~
    Beta-cryptoxanthin 3μg~
Vitamin C 14mg23%
Vitamin D ~IU (~μg)~%
    D2 Ergocalciferol ~IU (~μg)
    D3 Cholecalciferol ~IU (~μg)
Vitamin E ~mg~%
Vitamin K ~μg~%
    K1 - Dihydrophylloquinone ~μg~
    K2 - Menaquinone-4 ~μg~
Vitamin B12 0μg~%
Thiamin 0.014mg1%
Riboflavin 0.06mg4%
Niacin 0.46mg2%
Pantothenic acid ~mg~%
Vitamin B6 0.06mg3%
Folate 6μg2%
    Folic Acid 0μg~
    Food Folate 6μg~
    Dietary Folate Equivalents 6μg~
Choline ~mg~
Lycopene ~μg~
Lutein+Zeaxanthin ~μg~
Minerals  %DV
Calcium 56mg6%
Iron 0.3mg2%
Magnesium 85mg21%
Phosphorus 24mg2%
Sodium 5mg0%
Potassium 220mg6%
Zinc 0.12mg1%
Copper 0.08mg4%
Manganese ~mg~%
Selenium 0.6μg1%
Water 87.55g~
Ash 1.64g~
Fatty Acids
Omega 3 to Omega 6 Ratio0.12
Omega 6 to Omega 3 Ratio8.09
Total Omega 3s23mg
18D3 Linolenic23mg
18D3CN3 Alpha Linolenic(ALA)~mg
18D4 Stearidonic (SDA)0mg
20D3N3 Eicosatrienoic~mg
20D5 Eicosapentaenoic(EPA)0mg
22D5 Docosapentaenoic(DPA)0mg
22D6 Docosahexaenoic(DHA)0mg
Total Omega 6s186mg
18D2CN6 Linoleic(LA)~mg
18D2CLA Conjugated Linoleic(CLA)~mg
18D3CN6 Gamma-linolenic (GLA)~mg
20D2CN6 Eicosadienoic~mg
20D3N6 Di-homo-gamma-linolenic (DGLA)~mg
20D4N6 Arachidonic (AA)~mg
22D4 Adrenic (AA)~mg
Essential Amino Acids  %RDI
Histidine ~mg~%
Isoleucine ~mg~%
Leucine ~mg~%
Lysine ~mg~%
Methionine ~mg~%
Phenylalanine ~mg~%
Threonine ~mg~%
Tryptophan ~mg~%
Valine ~mg~%
Percent of Daily CalorieTarget
(2000 calories)
Percent Water Composition 87.6%
Protein to Carb Ratio (g/g) 0.07

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Disqus Comments
  1. Office Of Dietary Supplements Fact Sheet: Calcium
  2. National Osteoporosis Foundation. NOF osteoporosis prevention: risk factors for osteoporosis, 2003.
  3. U.S. Food and Drug Administration. Food labeling: health claims; calcium and osteoporosis, and calcium, vitamin D, and osteoporosis.
  4. Allender PS, Cutler JA, Follmann D, Cappuccio FP, Pryer J, Elliott P. Dietary calcium and blood pressure. Ann Intern Med 1996;124:825-31.
  5. Bucher HC, Cook RJ, Guyatt GH, Lang JD, Cook DJ, Hatala R, et al. Effects of dietary calcium supplementation on blood pressure. JAMA 1996;275:1016-22.
  6. McCarron D, Reusser M. Finding consensus in the dietary calcium-blood pressure debate. J Am Coll Nutr 1999;18:398S-405S.
  7. American Dietetic Association, Dietitians of Canada. Position of the American Dietetic Association and Dietitians of Canada: vegetarian diets. J Am Diet Assoc 2003;103:748-65.
  8. Rouse IL, Beilin LJ, Armstrong BK, Vandongen R. Blood-pressure-lowering effect of a vegetarian diet: controlled trial in normotensive subjects. Lancet 1983;1:5-10.
  9. Margetts BM, Beilin L, Armstrong BK, Vandongen R. Vegetarian diet in the treatment of mild hypertension: a randomized controlled trial. J Hypertens 1985:S429-31.
  10. Beilin LJ, Armstrong BK, Margetts BM, Rouse IL, Vandongen R. Vegetarian diet and blood pressure. Nephron 1987;47:37-41.
  11. Berkow SE, Barnard ND. Blood pressure regulation and vegetarian diets. Nutr Rev 2005;63:1-8.
  12. Slattery M, Edwards S, Boucher K, Anderson K, Caan B. Lifestyle and colon cancer: an assessment of factors associated with risk. Am J Epidemiol 1999;150:869-77.
  13. Kampman E, Slattery M, Bette C, Potter J. Calcium, vitamin D, sunshine exposure, dairy products, and colon cancer risk. Cancer Causes Control 2000;11:459-66.
  14. Holt P, Atillasoy E, Gilman J, Guss J, Moss SF, Newmark H, et al. Modulation of abnormal colonic epithelial cell proliferation and differentiation by low-fat dairy foods. JAMA 1998;280:1074-9.
  15. Biasco G, Paganelli M. European trials on dietary supplementation for cancer prevention. Ann N Y Acad Sci 1999;889:152-6.
  16. Cascinu S, Del Ferro E, Cioccolini P. Effects of calcium and vitamin supplementation on colon cancer cell proliferation in colorectal cancer. Cancer Invest 2000;18:411-6.
  17. Martinez ME, Willett WC. Calcium, vitamin D, and colorectal cancer: a review of epidemiologic evidence. Cancer Epidemiol Biomarkers Prev 1998;7:163-8.
  18. Chan JM, Stampfer MJ, Gann PH, Gaziano JM, Giovannucci EL. Dairy products, calcium, and prostate cancer risk in the Physicians Health Study. Am J Clin Nutr 2001;74:549-54.
  19. Giovannucci EL, Rimm EB, Wolk A, Ascherio A, Stampfer MJ, Colditz GA, et al. Calcium and fructose intake in relation to risk of prostate cancer. Cancer Res 1998;58:442-7.
  20. Chan JM, Giovannucci E, Andersson SO, Yuen J, Adami HO, Wok A. Dairy products, calcium, phosphorous, vitamin D, and risk of prostate cancer (Sweden). Cancer Causes Control 1998;9:559-66.
  21. Chan JM, Giovannucci EL. Dairy products, calcium, and vitamin D and risk of prostate cancer. Epidemiol Rev 2001;23:87-92.
  22. Rodriguez C, McCullough ML, Mondul AM, Jacobs EJ, Fakhrabadi-Shokoohi D, Giovannucci EL, et al. Calcium, dairy products, and risk of prostate cancer in a prospective cohort of United States men. Cancer Epidemiol Biomarkers Prev 2003;12:597-603.
  23. Kesse E, Bertrais S, Astorg P, Jaouen A, Arnault N, Galan P, et al. Dairy products, calcium and phosphorus intake, and the risk of prostate cancer: results of the French prospective SU.VI.MAX (Supplementation en Vitamines et Mineraux Antioxydants) study. Br J Nutr 2006;95:539-45.
  24. Mitrou PN, Albanes D, Weinstein SJ, Pietinen P, Taylor PR, Virtamo J, et al. A prospective study of dietary calcium, dairy products and prostate cancer risk (Finland). Int J Cancer 2007;120:2466-73.
  25. Chan JM, Pietinen P, Virtanen M, Chan JM, Pietinen P, Virtanen M, et al. Diet and prostate cancer risk in a cohort of smokers, with a specific focus on calcium and phosphorus (Finland). Cancer Causes Control 2000;11:859-67.
  26. Schuurman AG, Van den Brandt PA, Dorant E, Goldbohm RA. Animal products, calcium and protein and prostate cancer risk in the Netherlands Cohort Study. Br J Cancer 1999;80:1107-13.
  27. Kristal AR, Stanford JL, Cohen JH, Wicklund K, Patterson RE. Vitamin and mineral supplement use is associated with reduced risk of prostate cancer. Cancer Epidemiol Biomarkers Prev 1999;8:887-92.
  28. Vlajinac HD, Marinkovic JM, Ilic MD, Kocev NI. Diet and prostate cancer: a case-control study. Eur J Cancer 1997;33:101-7.
  29. Jackson RD, LaCroix AZ, Gass M, Wallace RB, Robbins J, Lewis CE, et al. Calcium plus vitamin D supplementation and the risk of fractures. N Engl J Med 2006;354:669-83.
  30. Curhan G, Willett WC, Rimm E, Stampher MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med 1993;328:833-8.
  31. Bihl G, Meyers A. Recurrent renal stone disease?advances in pathogenesis and clinical management. Lancet 2001;358:651-6.
  32. Hall WD, Pettinger M, Oberman A, Watts NB, Johnson KC, Paskett ED, et al. Risk factors for kidney stones in older women in the Southern United States. Am J Med Sci 2001;322:12-8.
  33. Borghi L, Schianchi T, Meschi T, Guerra A, Allegri F, Maggiore U, et al. Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria. N Engl J Med 2002;346:77-84.
  34. Shannon MT, Wilson BA, Stang CL. Health Professionals Drug Guide. Stamford, CT: Appleton and Lange, 2000.
  35. Jellin JM, Gregory P, Batz F, Hitchens K. Pharmacist's Letter/Prescriber's Letter Natural Medicines Comprehensive Database. 3rd ed. Stockton, CA: Therapeutic Research Facility, 2000.
  36. Peters ML, Leonard M, Licata AA. Role of alendronate and risedronate in preventing and treating osteoporosis. Cleve Clin J Med 2001;68:945-51.
  37. Gallagher JC, Goldgar D, Moy A. Total bone calcium in normal women: effect of age and menopause status. J Bone Min Res 1987;2:491-6.
  38. Dawson-Hughes B, Dallal GE, Krall EA, Sadowski L, Sahyoun N, Tannenbaum S. A controlled trial of the effect of calcium supplementation on bone density in postmenopausal women. N Engl J Med 1990;323:878-83.
  39. Elders PJ, Lips P, Netelenbos JC, van Ginkel FC, Khoe E, van der Vijgh WJ, et al. Long-term effect of calcium supplementation on bone loss in perimenopausal women. J Bone Min Res 1994;9:963-70.
  40. Abrams SA, Silber TJ, Esteban NV, Vieira NE, Stuff JE, Meyers R, et al. Mineral balance and bone turnover in adolescents with anorexia nervosa. J Pediatr 1993;123:326-31.
  41. Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. Washington, DC: National Academy Press, 1997.
  42. Weaver CM, Heaney RP. Calcium. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Lippincott Williams & Wilkins, 2006:194-210.
  43. Mark J Bolland, senior research fellow,1 Alison Avenell, clinical senior lecturer,2 John A Baron, professor,3 Andrew Grey, associate professor,1 Graeme S MacLennan, senior research fellow,2 Greg D Gamble, research fellow,1 and Ian R Reid, professor1. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ. 2010; 341: c3691. Published online 2010 July 29. doi: 10.1136/bmj.c3691.
  44. Mark J Bolland, research fellow1, P Alan Barber, senior lecturer1, Robert N Doughty, associate professor1, Barbara Mason, research officer1, Anne Horne, research fellow1, Ruth Ames, research officer1, Gregory D Gamble, research fellow1, Andrew Grey, associate professor1, Ian R Reid, professor1. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial. BMJ 2008; 336 doi: 10.1136/bmj.39440.525752.BE (Published 31 January 2008).
  45. Office Of Dietary Supplements Fact Sheet
  46. Appel LJ. Nonpharmacologic therapies that reduce blood pressure: A fresh perspective. Clin Cardiol 1999;22:1111-5.
  47. Simopoulos AP. The nutritional aspects of hypertension. Compr Ther 1999;25:95-100.
  48. Appel LJ, Moore TJ, Obarzanek E, Vollmer WM, Svetkey LP, Sacks FM, Bray GA, Vogt TM, Cutler JA, Windhauser MM, Lin PH, Karanja N. A clinical trial of the effects of dietary patterns on blood pressure. N Engl J Med 1997;336:1117-24.
  49. Saris NE, Mervaala E, Karppanen H, Khawaja JA, Lewenstam A. Magnesium: an update on physiological, clinical, and analytical aspects. Clinica Chimica Acta 2000;294:1-26.
  50. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. National Academy Press. Washington, DC, 1999.
  51. Paolisso G, Sgambato S, Gambardella A, Pizza G, Tesauro P, Varricchio H, D'Onofrio F. Daily magnesium supplements improve glucose handling in elderly subjects. Am J Clin Nutr 1992;55:1161-7.
  52. Altura BM and Altura BT. Magnesium and cardiovascular biology: An important link between cardiovascular risk factors and atherogenesis. Cell Mol Biol Res 1995;41:347-59.
  53. Ford ES. Serum magnesium and ischaemic heart disease: Findings from a national sample of US adults. Intl J of Epidem 1999;28:645-51.
  54. Liao F, Folsom A, Brancati F. Is low magnesium concentration a risk factor for coronary heart disease? The Atherosclerosis Risk in Communities (ARIC) Study. Am Heart J 1998;136:480-90.
  55. Ascherio A, Rimm EB, Hernan MA, Giovannucci EL, Kawachi I, Stampfer MJ, Willett WC. Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men. Circulation 1998;98:1198-204.
  56. Elisaf M, Milionis H, Siamopoulos K. Hypomagnesemic hypokalemia and hypocalcemia: Clinical and laboratory characteristics. Mineral Electrolyte Metab 1997;23:105-12.
  57. Xing JH and Soffer EE. Adverse effects of laxatives. Dis Colon Rectum 2001;44:1201-9.
  58. Mauskop A, Altura BM. Role of magnesium in the pathogenesis and treatment of migraines. Clin Neurosci. 1998;5(1):24-27.
  59. Peikert A, Wilimzig C, Kohne-Volland R. Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia. 1996;16(4):257-263.
  60. Pfaffenrath V, Wessely P, Meyer C, et al. Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study. Cephalalgia. 1996;16(6):436-440.
  61. Wang F, Van Den Eeden SK, Ackerson LM, Salk SE, Reince RH, Elin RJ. Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial. Headache. 2003;43(6):601-610.
  62. Bendich A. The potential for dietary supplements to reduce premenstrual syndrome (PMS) symptoms. J Am Coll Nutr. 2000;19(1):3-12.
  63. Rude RK. Magnesium deficiency: A cause of heterogeneous disease in humans. J Bone Miner Res 1998;13:749-58.
  64. Rude KR. Magnesium metabolism and deficiency. Endocrinol Metab Clin North Am 1993;22:377-95.
  65. Kelepouris E and Agus ZS. Hypomagnesemia: Renal magnesium handling. Semin Nephrol 1998;18:58-73.
  66. Ramsay LE, Yeo WW, Jackson PR. Metabolic effects of diuretics. Cardiology 1994;84 Suppl 2:48-56.
  67. Kobrin SM and Goldfarb S. Magnesium Deficiency. Semin Nephrol 1990;10:525-35.
  68. Lajer H and Daugaard G. Cisplatin and hypomagnesemia. Ca Treat Rev 1999;25:47-58.
  69. Tosiello L. Hypomagnesemia and diabetes mellitus. A review of clinical implications. Arch Intern Med 1996;156:1143-8.
  70. Paolisso G, Scheen A, D'Onofrio F, Lefebvre P. Magnesium and glucose homeostasis. Diabetologia 1990;33:511-4.
  71. Elisaf M, Bairaktari E, Kalaitzidis R, Siamopoulos K. Hypomagnesemia in alcoholic patients. Alcohol Clin Exp Res 1998;22:244-6.
  72. Abbott L, Nadler J, Rude RK. Magnesium deficiency in alcoholism: Possible contribution to osteoporosis and cardiovascular disease in alcoholics. Alcohol Clin Exp Res 1994;18:1076-82.
  73. Rude RK, Shils ME. Magnesium. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore: Lippincott Williams & Wilkins; 2006:223-247.
  74. Food and Nutrition Board, Institute of Medicine. Magnesium. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington D.C.: National Academy Press; 1997:190-249.
  75. Schwartz R, Walker G, Linz MD, MacKellar I. Metabolic responses of adolescent boys to two levels of dietary magnesium and protein. I. Magnesium and nitrogen retention. Am J Clin Nutr. 1973;26(5):510-518.
  76. Shils ME. Magnesium. In Modern Nutrition in Health and Disease, 9th Edition. (edited by Shils, ME, Olson, JA, Shike, M, and Ross, AC.) New York: Lippincott Williams and Wilkins, 1999, p. 169-92.
  77. Spencer H, Norris C, Williams D. Inhibitory effects of zinc on magnesium balance and magnesium absorption in man. J Am Coll Nutr. 1994;13(5):479-484.
  78. Torsten Bohn, Lena Davidsson*, Thomas Walczyk and Richard F. Hurrel Fractional magnesium absorption is signi?cantly lower in human subjects from a meal served with an oxalate-rich vegetable, spinach, as compared with a meal served with kale, a vegetable with a low oxalate content. Laboratory for Human Nutrition, Institute of Food Science and Nutrition, Swiss Federal Institute of Technology, Zurich, Switzerland (Received 27 May 2003 - Revised 7 November 2003 - Accepted 28 November 2003
  79. FDA Drug Safety Communication: Low magnesium levels can be associated with long-term use of Proton Pump Inhibitor drugs (PPIs)
  80. Charles Coudray, Christian Demigné, and Yves Rayssiguier. Effects of Dietary Fibers on Magnesium Absorption in Animals and Humans. J. Nutr. January 1, 2003 vol. 133 no. 1 1-4.
  81. R. A. McCance, E. M. Widdowson, and H. Lehmann. The effect of protein intake on the absorption of calcium and magnesium. Biochem J. 1942 September; 36(7-9): 686-691.
  82. New SA, Bolton-Smith C, Grubb DA, Reid DM. Nutritional influences on bone mineral density: a cross-sectional study in premenopausal women. Am J Clin Nutr. 1997;65(6):1831-1839.
  83. New SA, Robins SP, Campbell MK, et al. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? Am J Clin Nutr. 2000;71(1):142-151.
  84. Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr. 1999;69(4):727-736.
  85. Ascherio A, Rimm EB, Hernan MA, et al. Intake of potassium, magnesium, calcium, and fiber and risk of stroke among US men. Circulation. 1998;98(12):1198-1204.
  86. Iso H, Stampfer MJ, Manson JE, et al. Prospective study of calcium, potassium, and magnesium intake and risk of stroke in women. Stroke. 1999;30(9):1772-1779.
  87. Fang J, Madhavan S, Alderman MH. Dietary potassium intake and stroke mortality. Stroke. 2000;31(7):1532-1537.
  88. Bazzano LA, He J, Ogden LG, et al. Dietary potassium intake and risk of stroke in US men and women: National Health and Nutrition Examination Survey I epidemiologic follow-up study. Stroke. 2001;32(7):1473-1480.
  89. Green DM, Ropper AH, Kronmal RA, Psaty BM, Burke GL. Serum potassium level and dietary potassium intake as risk factors for stroke. Neurology. 2002;59(3):314-320.
  90. Barri YM, Wingo CS. The effects of potassium depletion and supplementation on blood pressure: a clinical review. Am J Med Sci. 1997;314(1):37-40.
  91. Hajjar IM, Grim CE, George V, Kotchen TA. Impact of diet on blood pressure and age-related changes in blood pressure in the US population: analysis of NHANES III. Arch Intern Med. 2001;161(4):589-593.
  92. Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med. 1997;336(16):1117-1124.
  93. Gennari FJ. Hypokalemia. N Engl J Med. 1998;339(7):451-458.
  95. Office of Dietary Suppliments Face Sheet: Vitamin C
  96. Gokce N, Keaney JF, Jr., Frei B, et al. Long-term ascorbic acid administration reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Circulation. 1999;99(25):3234-3240.
  97. Audera, C (2001). "Mega-dose vitamin C in treatment of the common cold: a randomised controlled trial". Medical Journal of Australia 389: 175.
  98. Hemilä, Harri; Chalker, Elizabeth; Douglas, Bob; Hemilä, Harri (2007). "Vitamin C for preventing and treating the common cold". Cochrane database of systematic reviews (Online) (3): CD000980
  99. Fleming DJ, Tucker KL, Jacques PF, Dallal GE, Wilson PW, Wood RJ (December 2002). "Dietary factors associated with the risk of high iron stores in the elderly Framingham Heart Study cohort". The American Journal of Clinical Nutrition 76 (6): 1375?84.
  100. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.
  101. Weinstein M, Babyn P, Zlotkin S. An orange a day keeps the doctor away: scurvy in the year 2000. Pediatrics 2001;108:E55.
  102. Hoffman FA. Micronutrient requirements of cancer patients. Cancer. 1985;55 (1 Suppl):295-300.
  103. Deicher R, Hörl WH. Vitamin C in chronic kidney disease and hemodialysis patients. Kidney Blood Press Res 2003;26:100-6.