Although vitamin C is essentially a nontoxic vitamin; however, it is important to be aware regarding the safety of high doses before the wide clinical use.
Minor side effects of vitamin C have been reported, many being reported in earlier studies. High doses of vitamin C (up to 1.5 g/kg three times a week as intravenously) were safe in cancer patients with normal renal function and perfect glucose-6-phosphate dehydrogenase activity. As the dose and duration of administration of vitamin C in sepsis are lower and shorter than those used in cancer patients, it seems that it is relatively safe for this population. In ongoing trials, safety of high doses of vitamin C is considered.
Data regarding the safety of high doses of vitamin C are scant. Until more data become available, caution should be applied in the use of high doses of vitamin C in patients with hemochromatosis, glucose-6-phosphate dehydrogenase deficiency, renal dysfunction, kidney stone, oxaluria, and pediatrics.
Department of Clinical Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
Correspondence to Hossein Khalili, Professor of Clinical Pharmacy, Department of Clinical Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, PO Box: 14155/6451, Tehran 1417614411, Iran. Tel: +98 21 66954709; fax: +98 21 66954709; e-mail: Khalilih@sina.tums.ac.ir