Should C Cause Concern?
Small amounts of vitamin C are essential for good health, but are large amounts harmful? high

doses increase the urinary levels of oxalate and uric acid, two chemicals that can cause kidney stone.

Large doess of vitamin C can cause nausea, indigestion, and diarrhoea, but these side effects are uncmmon and temporary. People with a certain enzyme deficiency (glucose-6-phosphate

dehydrogenase, or G6PD) can develop anaemia from high doses, but this, too, is uncommon. A much more common, but much less serious, problem is that large amounts of vitamin C can interfere with lab tests for sugar in the urine or blood in the faeces.

Although there are few well-documented clinical side effects of vitamin C, some experimental result counsel caution. Although normal amounts of vitamin C have a powerful antioxidant action, large amounts may promote oxidative damage. In a well-publicised experiment, British scientists gave a daily dose of 500mg of vitamin C to 30 volunteers; after six weeks, their blood cells showed increased traces of oxidative damage to DNA, Slimilarly, an American team reported that high levels of vitamin C enhance the production of DNA-damaging substances called genotoxins.

And several small studies have linked high doses of supplements to an accelerated thickening of the carotid artery, a marker of atherosclerosis; other studies, however, show the reverse.

All this research is preliminary, and none of it proves that vitamin C is harmful, even in large amounts. But it does provide some support for that common-sense standbly, moderation