1500 mg/day decreases protein-bound copper "Serum ceruloplasmin activity was significantly reduced (p less than 0.01) at every data point throughout the ascorbic acid supplementation period."
1000 mg/day decreased:
Effect not seen in guinea pigs and men
Also reduced in guinea pigs:
Also in rats:
Ceruloplasmin was not reduced at 605 mg/day in men, but its activity was
Magnesium was lowered in guinea pigs, but not ceruloplasmin
vitamin c in blood correlates with lower ceruloplasmin in humans
Small effect seen in monkeys on marginal copper diet
Low ceruloplasmin including from mutations is strongly implicated in PD and AD:
Low ceruloplasmin correlate with younger-onset PD
Mutations for low ceruloplasmin allow iron oxidation
Linus pauling institute:
Although vitamin C supplements have produced copper deficiency in guinea pigs (17), the effect of vitamin C supplements on copper nutritional status in humans is less clear. Two small studies in healthy, young adult men indicate that the oxidase activity of ceruloplasmin may be impaired by relatively high doses of supplemental vitamin C. In one study, vitamin C supplementation of 1,500 mg/day for two months resulted in a significant decline in ceruloplasmin oxidase activity (18). In the other study, supplements of 605 mg/day of vitamin C for three weeks resulted in decreased ceruloplasmin oxidase activity, although copper absorption did not decline (19). Neither of these studies found vitamin C supplementation to adversely affect copper nutritional status.