Vitamin C, or ascorbic acid is one of the most popular and widely recognized dietary supplements primarily because of its role in boosting the immune system. lts popularity began in the mid-70s, when Linus Pauling published his groundbreaking book Vitamin C and the Common Cold 39, and from that time sales of vitamin C supplements skyrocketed, and maintained unbroken popularity until today. 13, 21, 37
Many health benefits have been attributed to ascorbic acid 37 but not only can vitamin C help us feel better and stay healthy but it also has been found to support weight management. Nutritional studies have found an inverse relationship between vitamin C status and body weight, waist measurements, and waist-to-hip ratios. 5, 31, 33, 35
How does Vitamin C do this? The specific mechanisms may be as follows:
- Vitamin C is essential for the production of carnitine, which has a crucial role in lipid oxidation.
- Vitamin C may actually increase the inclination to exercise.
- Vitamin C may also help to modulate the actions of several hormones that are involved in fat-loss and/or fat accumulation, including cortisol, and insulin.
INCREASE FAT UTILIZATION AS A CO-FACTOR FOR THE PRODUCTION OF CARNITINE
Vitamin C is an essential cofactor for the biosynthesis of carnitine. The breakdown of fatty acids to produce energy mainly occurs in mitochondria – the “energy furnace” of the cells. The main function of carnitine is to transfer fatty acids to mitochondria for subsequent oxidation.
Clinical trials have shown that tissue carnitine levels are directly related to vitamin C supply. 29, 24, 30, 31, 32, 45 And since the oxidation of fatty is dependent on carnitine this may be one of the main mechanisms by which vitamin C affects fat oxidation. 22, 43
In a study, individuals with marginal vitamin C status oxidized 25% less fat per kilograms of body weight during a 60 minutes treadmill walk as compared to individuals with adequate vitamin C status!
Moreover, 500 mg per day of vitamin C supplementation among vitamin C depleted subjects increased fat energy expenditure during exercise 4-fold as compared to depleted control subjects. 31
(Johnston et al., 2006)
IMPROVE DESIRE TO EXERCISE
Deficiency of key nutrients may result in changes in mental state, and functioning. For example, depression, fatigue and irritability precede the physical symptoms of the vitamin C deficiency disease scurvy. 6, 7, 34 Clinical studies observed that vitamin C supplementation may be linked with decreased fatigue, reduction in the perception of exertion during physical activity, diminished aversion to exercise, and improved mood states. Hence, vitamin C may positively impact physical activity in the general population, and especially among the obese. 6, 7, 9, 10, 11, 32, 36
IMPROVE GLUCOSE CONTROL
Insulin plays an important role in the physiology of weight regulation. 4, 8 Insulin resistance, a condition in which cells fail to react normally to the insulin, is a driving factor in the development of type 2 diabetes mellitus, and is associated with a number of health conditions including obesity, and especially central adiposity. It may also make harder to control appetite by disturbing the believed role of insulin as a neuropeptide, involved in satiety, and appetite regulation. 2, 12, 19, 20, 25, 47, 41, 42, 48
As obesity and diabetes reach epidemic levels in the developed countries, the role of insulin resistance is gaining much attention. The possible insulin-sensitizing properties of vitamin C has been found in several investigations. 16, 17, 18, 30, 46, 48
Data from the EPIC-Norfolk study found an inverse relationship between plasma vitamin C and plasma glycated hemoglobin (HbA1c), a reliable indicator of insulin resistance. 16, 44, 48
Studies suggest that chronic low-grade inflammation and oxidative stress play a role in the development of insulin resistance, while antioxidants such as vitamin C may play a protective role against the development of impaired insulin sensitivity and type 2 diabetes. 16, 44, 48
HELP TO MANAGE STRESS INDUCED ADIPOSITY
Cortisol is glucocorticoid hormone that is released by the adrenal glands in response to stress as part of the “fight-or-flight” mechanism. It is essential for survival, but chronic stress, and thus chronic exposure to elevated cortisol levels is associated with adiposity and the persistence of obesity over time. 1, 18, 27
Studies have shown that Vitamin C may play a role in the regulation of glucocorticoid release, especially in highly stress situations. 3, 18, 38, 40 In a study, supplementation with 1500 mg of vitamin C among ultramarathon runners resulted a significantly lower post-race serum cortisol compared to no supplementation, or even to supplementation with 500 mg. 40
Official recommendations for adults: 15, 26
set by the Institute of Medicine (US)
set by the European Food Safety Authority (EFSA)
set by the European Food Safety Authority (EFSA)
Studies mentioned above found beneficial effects at higher level of vitamin C consumption, in the range of 200 to 3000 mg of vitamin C per day. 3, 6, 9, 10, 13, 23, 32, 40, 50
According to its safety health authorities and organizations established upper intake levels for nutrients to determining safety of dietary bioactive components.
Tolerable upper intake level (UL) is the maximum level of total chronic daily intake of a particular nutrient judged to be unlikely to pose a risk of adverse health effects.
Institute of Medicine (US) set a tolerable upper intake level of 2000 mg per day for vitamin C for adults. 26
- Abraham S. b, Rubino D, Sinaii N, Ramsey S, Nieman L. k. Cortisol, obesity, and the metabolic syndrome: a cross‐sectional study of obese subjects and review of the literature. Obesity 2013;21:E105‐
- Bonora E, Kiechl S, Willeit J, Oberhollenzer F, Egger G, Meigs JB, Bonadonna RC, Muggeo M.: Insulin resistance as estimated by homeostasis model assessment predicts incident symptomatic cardiovascular disease in caucasian subjects from the general population: the Bruneck study. Diabetes Care. 2007 Feb; 30(2):318-24.
- Brody S, Preut R, Schommer K, Schürmeyer TH.: A randomized controlled trial of high dose ascorbic acid for reduction of blood pressure, cortisol, and subjective responses to psychological stress. Psychopharmacology (Berl). 2002 Jan;159(3):319-24. Epub 2001 Nov 20.
- Cancello R, Tounian A, Poitou Ch, Clément K.: Adiposity signals, genetic and body weight regulation in humans. Diabetes Metab. 2004 Jun;30(3):215-27.
- Canoy D, Wareham N, Welch A, Bingham S, Luben R, Day N, Khaw KT. Plasma ascorbic acid concentrations and fat distribution in 19 068 British men and women in the European Prospective Investigation into Cancer and Nutrition Norfolk cohort study. Am J Clin Nutr. 2005;82:203–209
- Carr AC, Vissers MC.: Good nutrition matters: hypovitaminosis C associated with depressed mood and poor wound healing. N Z Med J. 2012 Sep 21; 125(1362):107-9.
- Carr AC, Bozonet SM, Pullar JM, Vissers MCM. Mood improvement in young adult males following supplementation with gold kiwifruit, a high-vitamin C food. Journal of Nutritional Science. 2013;2:e24. doi:10.1017/jns.2013.12.
- Chaptini, L., Peikin, S.: Physiology of Weight Regulation, in Practical Gastroenterology and 2016, Hepatology Board Review Toolkit (eds M. B. Wallace, B. A. Aqel, K. D. Lindor and K. R. Devault), John Wiley & Sons, Ltd, Oxford, UK. doi: 10.1002/9781119127437.ch102
- Cheraskin E, Ringsdorf WM Jr, Medford FH: Daily vitamin C consumption and fatigability. J Am Geriatr Soc. 1976 Mar; 24(3):136-7.
- Cocchi P, Silenzi M, Calabri G, Salvi G: Antidepressant effect of vitamin C. Pediatrics. 1980 Apr; 65(4):862-3.
- Dalle Grave R, Centis E, Marzocchi R, El Ghoch M, Marchesini G. Major factors for facilitating change in behavioral strategies to reduce obesity. Psychology Research and Behavior Management. 2013;6:101-110. doi:10.2147/PRBM.S40460.
- Després JP, Lemieux I, Bergeron J, Pibarot P, Mathieu P, Larose E, Rodés-Cabau J, Bertrand OF, Poirier P.: Abdominal obesity and the metabolic syndrome: contribution to global cardiometabolic risk. Arterioscler Thromb Vasc Biol. 2008 Jun; 28(6):1039-49.
- Douglas RM, Hemilä H, Chalker E, Treacy B.: Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD000980.
- European Food Safety Authority (EFSA): Tolerable upper intake levels for vitamins and minerals. Scientific Committee on Food. Scientific Panel on Dietetic Products, Nutrition and Allergies. European Food Safety Authority 2006 ISBN: 92-9199-014-0. http://www.efsa.europa.eu/sites/default/files/efsa_rep/blobserver_assets/ndatolerableuil.pdf
- European Food Safety Authority (EFSA) Scientific Opinion on Dietary Reference Values for vitamin C. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). EFSA Journal 2013;11(11):3418
- Feskens E.J.M., Virtanen S.M., Räsänen L., Tuomilehto J., Stengård J., Pekkanen J., Nissinen A., Kromhout D. Dietary factors determining diabetes and impaired glucose tolerance: A 20-year follow-up of the Finnish and Dutch cohorts of the Seven Countries Study. Diabetes Care. 1995, 18, 1104–1112.
- Garcia-Diaz DF, Campion J, Milagro FI, Boque N, Moreno-Aliaga MJ, Martinez JA.: Vitamin C inhibits leptin secretion and some glucose/lipid metabolic pathways in primary rat adipocytes. J Mol Endocrinol. 2010 Jul;45(1):33-43. doi: 10.1677/JME-09-0160. Epub 2010 Apr 16.
- Garcia-Diaz DF, Lopez-Legarrea P, Quintero P, Martinez JA.: Vitamin C in the treatment and/or prevention of obesity. J Nutr Sci Vitaminol (Tokyo). 2014;60(6):367-79. doi: 10.3177/jnsv.60.367.
- Gerozissis K.: Brain insulin and feeding: a bi-directional communication. Eur J Pharmacol. 2004 Apr 19;490(1-3):59-70.
- Hardy OT, Czech MP, Corvera S. What causes the insulin resistance underlying obesity? Current opinion in endocrinology, diabetes, and obesity. 2012;19(2):81-87. doi:10.1097/MED.0b013e3283514e13.
- Hemilä H, Chalker E.: Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013 Jan 31;(1):CD000980. doi: 10.1002/14651858.CD000980.pub4
- Hoppel C.: The role of carnitine in normal and altered fatty acid metabolism. Am J Kidney Dis. 2003;41:S4–12.
- Huck CJ, Johnston CS, Beezhold BL, Swan PD: Vitamin C status and perception of effort during exercise in obese adults adhering to a calorie-reduced diet. Nutrition. 2013 Jan; 29(1):42-5.
- Hughes RE, Hurley RJ, Jones E. Dietary ascorbic acid and muscle carnitine (beta-OH-gamma-(trimethylamino) butyric acid) in guinea-pigs. Br J Nutr. 1980;43:385–387. doi: 10.1079/BJN19800102.
- Iepsen EW, Lundgren J, Holst JJ, Madsbad S, Torekov SS: Successful weight loss maintenance includes long-term increased meal responses of GLP-1 and PYY3-36. Eur J Endocrinol. 2016 Jun;174(6):775-84. doi: 10.1530/EJE-15-1116. Epub 2016 Mar 14.
- Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 5, Vitamin C. Available from: https://www.ncbi.nlm.nih.gov/books/NBK225480/
- Jackson SE, Kirschbaum C, Steptoe A. Hair cortisol and adiposity in a population‐based sample of 2,527 men and women aged 54 to 87 years. Obesity (Silver Spring, Md). 2017;25(3):539-544. doi:10.1002/oby.21733.
- Jeppesen J, Hansen TW, Rasmussen S, Ibsen H, Torp-Pedersen C, Madsbad S.: Insulin resistance, the metabolic syndrome, and risk of incident cardiovascular disease: a population-based study. J Am Coll Cardiol. 2007 May 29; 49(21):2112-9.
- Johnston CS, Solomon RE, Corte C. Vitamin C depletion is associated with alterations in blood histamine and plasma free carnitine in adults. J Am Coll Nutr. 1996;15:586–591.
- Johnston CS.: Strategies for healthy weight loss: from vitamin C to the glycemic response. J Am Coll Nutr. 2005 Jun;24(3):158-65.
- Johnston CS, Corte C, Swan PD. Marginal vitamin C status is associated with reduced fat oxidation during submaximal exercise in young adults. Nutrition & Metabolism. 2006;3:35. doi:10.1186/1743-7075-3-35.
- Johnston CS, Barkyoumb GM, Schumacher SS. Vitamin C Supplementation Slightly Improves Physical Activity Levels and Reduces Cold Incidence in Men with Marginal Vitamin C Status: A Randomized Controlled Trial. Nutrients. 2014;6(7):2572-2583. doi:10.3390/nu6072572.
- Kant AK. Interaction of body mass index and attempt to lose weight in a national sample of US adults: association with reported food and nutrient intake, and biomarkers. Eur J Clin Nutr. 2003;57:249–259. doi: 10.1038/sj.ejcn.1601549
- Levine M, Conry-Cantilena C, Wang Y, Welch RW, Washko PW, Dhariwal KR, Park JB, Lazarev A, Graumlich JF, King J, Cantilena LR: Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proc Natl Acad Sci U S A. 1996 Apr 16; 93(8):3704-9.
- Moor de Burgos A, Wartanowicz M, Ziemlanski S. Blood vitamin and lipid levels in overweight and obese women. Eur J Clin Nutr. 1992;46:803–808
- Ottevaere C, Huybrechts I, Béghin L, Cuenca-Garcia M, De Bourdeaudhuij I, Gottrand F, Hagströmer M, Kafatos A, Le Donne C, Moreno LA, Sjöström M, Widhalm K, De Henauw S, HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study Group. Relationship between self-reported dietary intake and physical activity levels among adolescents: the HELENA study. Int J Behav Nutr Phys Act. 2011 Feb 6; 8():8.
- Naidu KA.: Vitamin C in human health and disease is still a mystery ? An overview. Nutrition Journal. 2003;2:7. doi:10.1186/1475-2891-2-7.
- Padayatty SJ, Doppman JL, Chang R, Wang Y, Gill J, Papanicolaou DA, Levine M.: Human adrenal glands secrete vitamin C in response to adrenocorticotrophic hormone. Am J Clin Nutr. 2007 Jul;86(1):145-9.
- Pauling L.: Vitamin C and the Common Cold. 1976 San Francisco: W. H. Freeman.
- Peters EM, Anderson R, Nieman DC, Fickl H, Jogessar V.: Vitamin C supplementation attenuates the increases in circulating cortisol, adrenaline and anti-inflammatory polypeptides following ultramarathon running. Int J Sports Med. 2001 Oct;22(7):537-43.
- Preis SR, Massaro JM, Robins SJ, et al. Abdominal Subcutaneous and Visceral Adipose Tissue and Insulin Resistance in the Framingham Heart Study. Obesity (Silver Spring, Md). 2010;18(11):2191-2198. doi:10.1038/oby.2010.59.
- Reaven GM.: Banting lecture 1988. Role of insulin resistance in human disease. Diabetes. 1988 Dec; 37(12):1595-607.
- Reda E, D’Iddio S, Nicolai R, Benatti P, Calvani M. The carnitine system and body composition. Act Diabetol. 2003;40:S106–113. doi: 10.1007/s00592-003-0040-z.
- Sargeant LA, Wareham NJ, Bingham S, Day NE, Luben RN, Oakes S, Welch A, Khaw KT.: Vitamin C and hyperglycemia in the European Prospective Investigation into Cancer–Norfolk (EPIC-Norfolk) study: a population-based study. Diabetes Care. 2000 Jun;23(6):726-32.
- Sartorelli L, Ciman M, Mantovani G, Siliprandi N. Carnitine transport in rat heart slices: II. The carnitine/deoxycarnitine antiport. Ital J Biochem. 1985;34:282–287.
- Shoelson SE, Lee J, Goldfine AB. Inflammation and insulin resistance. Journal of Clinical Investigation. 2006;116(7):1793-1801. doi:10.1172/JCI29069.
- Sims EA, Danforth E. Expenditure and storage of energy in man. Journal of Clinical Investigation. 1987;79(4):1019-1025.
- Wilcox G.: Insulin and Insulin Resistance. Clinical Biochemist Reviews. 2005;26(2):19-39.
- Wilson R, Willis J, Gearry R, et al. Inadequate Vitamin C Status in Prediabetes and Type 2 Diabetes Mellitus: Associations with Glycaemic Control, Obesity, and Smoking. Nutrients. 2017;9(9):997. doi:10.3390/nu9090997.
- Zhang M, Robitaille L, Eintracht S, Hoffer LJ.: Vitamin C provision improves mood in acutely hospitalized patients. Nutrition. 2011 May;27(5):530-3. doi: 10.1016/j.nut.2010.05.016. Epub 2010 Aug 5.