Vitamin C is a water soluble vitamin, and thus our body does not retain it in large amounts. It is a strong antioxidant that has a key role in protecting against oxidative damage and tissue trauma. Vitamin C can neutralize potentially harmful reactions in the watery parts of our body, such as blood and the fluid inside and surrounding cells. It is one of the vitamins that many athletes consume in rather substantial amounts; therefore they are more familiar with it than with other vitamins. Recommended Daily Allowance (RDA) for vitamin C The current RDA for vitamin C is 90mg/d for males (+19yrs) and 75mg/d for females (+19yrs). Active individuals need more vitamin C due to the increased stress associated with exercise. Highly active athletes may require at least 100mg/d of vitamin C to keep normal vitamin C status and protect their body from the oxidative stressors of exercise. People can get this amount from a normal diet (1). Vitamin C supplementation and different types of exercise
Some studies indicate that vitamin C supplementation does not improve physical performance in well-nourished athletes. However, others suggest that supplementation (600mg/d) for 21 days before a race enhances resistance to the post-race upper respiratory tract infections that occur commonly in ultramarathoners and may reduce the severity of such infections in sedentary people. High-dose vitamin C supplementation (1000mg/d) for 21-days in marathoners and cross-country skiers reduced the risk of colds by 50%. Vitamin C supplements also attenuated the increase in concentrations of plasma interleukin-6, -8, and -10 in runners ingesting 1500_mg/d for 1_week prior to the race and on race day. Interleukins are a family of proteins produced by macrophages and T-lymphocytes that involved in inflammation and immunity. They control some aspects of the immune response by conveying signals between white blood cells. Some weight trainers, especially bodybuilders, believe that benefits from vitamin C include antioxidant properties, limiting cortisol production, helping the growth of steroid hormones, helping with iron absorption, reducing muscle soreness, and boosting the immune system.
It is believed that vitamin C for bodybuilding should be consumed in daily dosages of about 500-1500mg/d, spread out over 2-3_doses. According to Jakeman’s study, vitamin C supplementation (400_mg/d) for 21 days before and 7 days after performing 60 min of box-stepping exercise had a protective effect against eccentric exercise-induced muscle damage in young healthy men (2). Vitamin C was also reported to reduce soreness after bouts of sit-ups. A 12 hour delay in the beginning of muscle stiffness with participants taking vitamin C was also noted. Vitamin C (400mg/d) for a 2 week period before an intermittent shuttle run showed a modest decrease in soreness with both interleukin-6 and malondialdehyde increases compared to placebo. Fresh fruits and vegetables are the best sources of vitamin C. Among the excellent sources of vitamin C are peppers, strawberries, oranges, lemon juice, papayas, cauliflower, kale, mustard greens, and Brussels sprouts (3). In sum, the results of vitamin C studies are inconsistent.
Some show that vitamin C supplementation improves physical performance in those who are vitamin C deficient. Other studies suggest that vitamin C supplementation does not boost the performance capacity in those who are not deficient. With respect to the available evidence, we can conclude that vitamin C supplementation may help to improve physical performance in athletes who have a vitamin C deficiency (4). Blood levels of vitamin C remain steady at nearly 200 mg per day. Although vitamin C can be well tolerated at doses well above the RDA recommendations, adverse effects can occur at doses above 3 grams per day, although overload is unlikely. The common 'threshold' side effect of megadoses is diarrhea. Other possible adverse effects include increased oxalate excretion and kidney stones, increased uric acid excretion, preoxidant effects, iron overload, reduced absorption of vitamin B12 and copper, increased oxygen demand and acid erosion of the teeth (5). Petersen EW, Ostrowski K, Ibfelt T, Richelle M, Offord E, Halkjaer-Kristensen J, et al. Effect of vitamin supplementation on cytokine response and on muscle damage after strenuous exercise Am J Physiol Cell Physiol 2001 Jun;280(6):C1570-5.
Jakeman P, Maxwell S. Effect of antioxidant vitamin supplementation on muscle function after eccentric exercise Eur J Appl Physiol Occup Physiol 1993;67(5):426-430. Exercise immunology: nutritional countermeasures Can J Appl Physiol 2001;26 Suppl:S45-55. Ilhan N, Kamanli A, Ozmerdivenli R, Ilhan N. Variable effects of exercise intensity on reduced glutathione, thiobarbituric acid reactive substance levels, and glucose concentration. Arch Med Res 2004 Jul-Aug;35(4):294-300. Powers SK, DeRuisseau KC, Quindry J, Hamilton KL. Dietary antioxidants and exercise J Sports Sci 2004 Jan;22(1):81-94. Vitamin C is a naturally occurring, water-soluble vitamin found in many different types of fruits and vegetables, and can also be taken as a nutritional supplement for its potential health benefits, such as its antioxidant properties. Despite its potential health benefits, vitamin C has some disadvantages as well, such as the risk for developing side effects when ingesting large doses of the nutrient.
As with all nutritional supplements and vitamins, consult your physician before taking vitamin C supplements to make sure it is safe for you. Large doses of vitamin C, or ascorbic acid, taken at one time might cause gastrointestinal distress, especially if you consume it on an empty stomach, according to the book, "Nutrition for Health, Fitness and Sport." Symptoms of gastrointestinal distress include upset stomach, nausea, indigestion, stomach cramps, headaches, fatigue, diarrhea and vomiting. These effects are usually mild and are related to the acidity of vitamin C, which can be minimized when taken with food or when combined with an alkaline base, such as calcium ascorbate, to help neutralize the acidity. Hemochromatosis is a condition that involves excess iron in your body, which can have toxic effects. According to the National Heart, Lung and Blood Institute, a high intake of vitamin C can make the symptoms of hemochromatosis worse because vitamin C helps your body absorb more iron from foods and supplements.
Hemochromatosis can poison your organs and cause organ failure, damaging your heart, liver and pancreas. Vitamin C supplementation can affect the production of certain sex hormones, such as progesterone, especially during the early stages of pregnancy in women, according to the book, "New Encyclopedia of Vitamins, Minerals, Supplements and Herbs." Progesterone is important in the gestation process during pregnancy, and its release can be inhibited due to high concentrations of vitamin C circulating in your bloodstream. Low progesterone levels during pregnancy can increase the risk of the fetus developing birth defects. Vitamin C supplementation might have a negative effect on athletic performance. In a 2008 study published by the "American Journal of Clinical Nutrition," vitamin C supplementation decreased endurance capacity in athletes. The researchers say the adverse effects might be related to vitamin C's capacity to reduce the exercise-induced expression of key factors that are involved in the formation of new muscle cells, thereby preventing some of the natural cellular adaptations to exercise.
Excess vitamin C intake increases the risk of kidney stones, according to a report from Harvard Medical School, and men are particularly at risk. When some break down vitamin C in the body, it converts into oxalate, which can promote the formation of kidney stones. You should avoid high doses of vitamin C, and stay closer to the recommended intake of 75 milligrams per day for women, and 90 milligrams per day for men. Mechanisms of Vitamin C (Ascorbic Acid) Side Effects of a Vitamin C Overdose The Toxicity Level for Vitamin C What Are the Health Benefits of Sodium Ascorbate? Disadvantages of Different Vegetables & Fruits What Are the Benefits of Vitamin C Powder? Low-Sugar Fruits & Vegetables Vitamin C & Pregnancy Termination Does Taking Vitamins on an Empty Stomach Cause Nausea? Vitamins Recommended for a 40-Year-Old Woman Cons of Vitamin C Before Surgery How Much Vitamin C is used for Constipation? Is Extra Vitamin C Safe When Breastfeeding?