Fruits and vegetables are the best sources of vitamin C (see Table 2) [ 12]. Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors of vitamin C to the American diet [ 8]. Other good food sources include red and green peppers, kiwifruit, broccoli, strawberries, Brussels sprouts, and cantaloupe (see Table 2) [ 8, 12]. Although vitamin C is not naturally present in grains, it is added to some fortified breakfast cereals. The vitamin C content of food may be reduced by prolonged storage and by cooking because ascorbic acid is water soluble and is destroyed by heat [ 6, 8]. Steaming or microwaving may lessen cooking losses. Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually consumed raw. Consuming five varied servings of fruits and vegetables a day can provide more than 200 mg of vitamin C. Table 2: Vitamin C Content of Selected Foods [ 12] Food Bates CJ. Bioavailability of vitamin C. Eur J Clin Nutr 1997;51 (Suppl 1):S28-33. [ PubMed abstract] The safety and efficacy of the use of vitamin C and other antioxidants during cancer treatment is controversial [ 53, 91, 92]. Some data indicate that antioxidants might protect tumor cells from the action of radiation therapy and chemotherapeutic agents, such as cyclophosphamide, chlorambucil, carmustine, busulfan, thiotepa, and doxorubicin [ 54, 91, 93, 94]. At least some of these data have been criticized because of poor study design [ 52]. Other data suggest that antioxidants might protect normal tissues from chemotherapy- and radiation-induced damage [ 91, 93] and/or enhance the effectiveness of conventional cancer treatment [ 95]. However, due to the physiologically tight control of vitamin C, it is unclear whether oral vitamin C supplements could alter vitamin C concentrations enough to produce the suggested effects. Individuals undergoing chemotherapy or radiation should consult with their oncologist prior to taking vitamin C or other antioxidant supplements, especially in high doses [ 54]. 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) Jacob RA, Sotoudeh G. Vitamin C function and status in chronic disease. Nutr Clin Care 2002;5:66-74. [ PubMed abstract]

Levine M, Wang Y, Padayatty SJ, Morrow J. A new recommended dietary allowance of vitamin C for healthy young women. Proc Natl Acad Sci U S A 2001;98:9842-6. [ PubMed abstract] Sesso HD, Buring JE, Christen WG, Kurth T, Belanger C, MacFadyen J, et al. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. JAMA 2008;300:2123-33. [ PubMed abstract]

Lin J, Cook NR, Albert C, Zaharris E, Gaziano JM, Van Denburgh M, et al. Vitamins C and E and beta carotene supplementation and cancer risk: a randomized controlled trial. J Natl Cancer Inst 2009;101:14-23. [ PubMed abstract] Padayatty SJ, Levine M. Antioxidant supplements and cardiovascular disease in men. JAMA 2009;301:1336. [ PubMed abstract]

Crandall was the first to create a physician-curated, hypoallergenic makeup line that is still widely popular today (and we deem that a real success story). From a wide range of product offerings from eyeshadow to face makeup and skincare, there's something for everyone from Physicians Formula, especially those looking for an alternative to any products containing talc. Today, vitamin C deficiency and scurvy are rare in developed countries [ 8]. Overt deficiency symptoms occur only if vitamin C intake falls below approximately 10 mg/day for many weeks [ 5-8, 22, 23]. Vitamin C deficiency is uncommon in developed countries but can still occur in people with limited food variety. Groups at Risk of Vitamin C Inadequacy Estimated Average Requirement (EAR): Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals

Bleys J, Miller ER 3rd, Pastor-Barriuso R, Appel LJ, Guallar E. Vitamin-mineral supplementation and the progression of atherosclerosis: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2006;84:880-7. [ PubMed abstract] Supplements typically contain vitamin C in the form of ascorbic acid, which has equivalent bioavailability to that of naturally occurring ascorbic acid in foods, such as orange juice and broccoli [ 14-16]. Other forms of vitamin C supplements include sodium ascorbate; calcium ascorbate; other mineral ascorbates; ascorbic acid with bioflavonoids; and combination products, such as Ester-C, which contains calcium ascorbate, dehydroascorbate, calcium threonate, xylonate and lyxonate [ 17]. Carr A, Frei B. Does vitamin C act as a pro-oxidant under physiological conditions? FASEB J 1999 Jun;13:1007-24. [ PubMed abstract] Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. [ PubMed abstract]

Myint PK, Luben RN, Welch AA, Bingham SA, Wareham NJ, Khaw KT. Plasma vitamin C concentrations predict risk of incident stroke over 10 y in 20 649 participants of the European Prospective Investigation into Cancer Norfolk prospective population study. Am J Clin Nutr 2008;87:64-9. [ PubMed abstract] Frei B, England L, Ames BN. Ascorbate is an outstanding antioxidant in human blood plasma. Proc Natl Acad Sci U S A 1989;86:6377-81. [ PubMed abstract] Chong EW, Wong TY, Kreis AJ, Simpson JA, Guymer RH. Dietary antioxidants and primary prevention of age related macular degeneration: systematic review and meta-analysis. BMJ 2007;335:755. [ PubMed abstract] Podmore ID, Griffiths HR, Herbert KE, Mistry N, Mistry P, Lunec J. Vitamin C exhibits pro-oxidant properties. Nature 1998;392:559. [ PubMed abstract]Table 1 lists the current RDAs for vitamin C [ 8]. The RDAs for vitamin C are based on its known physiological and antioxidant functions in white blood cells and are much higher than the amount required for protection from deficiency [ 4, 8, 11]. For infants from birth to 12 months, the FNB established an AI for vitamin C that is equivalent to the mean intake of vitamin C in healthy, breastfed infants. Table 1: Recommended Dietary Allowances (RDAs) for Vitamin C [ 8] Age Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals

Padayatty SJ, Sun H, Wang Y, Riordan HD, Hewitt SM, Katz A, Wesley RA, Levine M. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann Intern Med 2004;140:533-7. [ PubMed abstract] Due to the enhancement of nonheme iron absorption by vitamin C, a theoretical concern is that high vitamin C intakes might cause excess iron absorption. In healthy individuals, this does not appear to be a concern [ 8]. However, in individuals with hereditary hemochromatosis, chronic consumption of high doses of vitamin C could exacerbate iron overload and result in tissue damage [ 4, 8]. Taylor PR, Li B, Dawsey SM, Li JY, Yang CS, Guo W, et al. Prevention of esophageal cancer: the nutrition intervention trials in Linxian, China. Linxian Nutrition Intervention Trials Study Group. Cancer Res 1994;54(7 Suppl):2029s-31s. [ PubMed abstract] Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men. J Urol 1996;155:1847-51. [ PubMed abstract] Lee SH, Oe T, Blair IA. Vitamin C-induced decomposition of lipid hydroperoxides to endogenous genotoxins. Science 2001;292:2083-6. [ PubMed abstract]Gershoff SN. Vitamin C (ascorbic acid): new roles, new requirements? Nutr Rev 1993;51:313-26. [ PubMed abstract] Results from prospective studies examining associations between vitamin C intake and cardiovascular disease risk are conflicting [ 56]. In the Nurses' Health Study, a 16-year prospective study involving 85,118 female nurses, total intake of vitamin C from both dietary and supplemental sources was inversely associated with coronary heart disease risk [ 58]. However, intake of vitamin C from diet alone showed no significant associations, suggesting that vitamin C supplement users might be at lower risk of coronary heart disease. A much smaller study indicated that postmenopausal women with diabetes who took at least 300 mg/day vitamin C supplements had increased cardiovascular disease mortality [ 59]. Douglas RM, Hemilä H. Vitamin C for preventing and treating the common cold. PLoS Med 2005;2:e168. [ PubMed abstract] Honarbakhsh S, Schachter M. Vitamins and cardiovascular disease. Br J Nutr 2008:1-19. [ PubMed abstract]