NOW Supplements, Vitamin C Crystals (Ascorbic Acid) Powder , Antioxidant Protection*, 8-Ounce

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Studies have not been done to see if vitamin C intake below the RDA or at doses higher than the UL can cause behavior or learning issues. Lee B, Oh SW, Myung SK. Efficacy of vitamin C supplements in prevention of cancer: a meta-analysis of randomized controlled trials. Korean J Fam Med. 2015;36(6):278-285. doi:10.4082/kjfm.2015.36.6.278 Quidel S, et al. What are the effects of vitamin C on the duration and severity of the common cold? Medwave. 2018; doi:10.5867/medwave.2018.06.7260.

Pelletier, O. & Keith, M.O. Bioavailability of synthetic and natural ascorbic acid. Journal of the American Dietetic Association. 1974; 64: 271-275 Viscovich M, Lykkesfeldt J, Poulsen HE. Vitamin C pharmacokinetics of plain and slow release formulations in smokers. Clinical nutrition. 2004;23(5):1043-1050. (PubMed) A study of three men and one woman found 1 gram of ascorbic acid to be equally well absorbed from solution, tablets, and chewable tablets, but the absorption from a timed-release capsule was 50% lower. Absorption was assessed by measuring urinary excretion of ascorbic acid after an intravenous dose of ascorbic acid and then comparing it to urinary excretion after the oral dosage forms (4).

Ran L, Zhao W, Wang J, et al. Extra dose of vitamin c based on a daily supplementation shortens the common cold: a meta-analysis of 9 randomized controlled trials. BioMed Research International. 2018;2018:1-12.

Antioxidants: In depth. National Center for Complementary and Integrative Health. https://www.nccih.nih.gov/health/antioxidants-in-depth. Accessed Oct. 11, 2020.Chromium ascorbate: The recommended dietary intake ( AI) for chromium is 30-35 μg/day for adult men and 20-25 μg/day for adult women. A maximum upper level (UL) of intake has not been determined by the US Food and Nutrition Board (see Chromium).

National Center for Advancing Translational Sciences. Genetic and Rare Diseases Information Center. Scurvy.

Lab tested for potency and quality

Simonson W. Should vitamin C routinely be given with oral iron supplements? Geriatr Nurs. 2019;40(3):327-328. doi:10.1016/j.gerinurse.2019.05.007 Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;(1):CD000980. doi:10.1002/14651858.CD000980.pub4