Larger amounts of Vitamin C lower Manganese levels and aid greater insulin production in those capable of producing insulin, which may be beneficial for Type II diabetics, but it would worsen those with hypoglycemic tendencies that exhibit low sodium, since sodium slows insulin response, so a very high intake of Vitamin C would create larger insulin spikes. By lowering manganese, very high doses of Vitamin C also affect glycogen stores in the liver... Full Text