Tolerance and effects of high doses of ascorbic acid. Dosis facit venenum.

The few literature references suggesting adverse effects of high doses of ascorbic acid are outnumbered by a large number of clinical studies in which no adverse effects have been observed. Up to 5 g ascorbic acid daily may be administered safely even over a long term. Favourable effects of even higher doses in man may justify therapeutic trials in the range of 15 g daily which in our trials have proven safe during treatment of up to 2 years. Nevertheless, trials in the high dosage range mentioned should always be closely supervised by a physician, being aware that exceptional behaviour can occur at any time, as exception proves the rule.