Richard -
In Dr. Murray's book, Encyclopedia of Supplements.... he states that the
safe and adequate intake of copper for adults is 1.5 to 3 milligrams.
Zinc interferes with copper absorption and is recommended at a ratio to copper of 10:1 so if zinc is supplemented at a dose of 30 mg. then it would require a dosage of 3 milligrams of copper.
He does not recommend copper at a level greater than 3 milligrams.
Copper is an emetic - 10 milligrams produces nausea and 60 milligrams usually produces vomiting. A lethal dose can be as low as 3.5 GRAMS.
Copper toxicity is rare. Then he says someting contradictory.... "It is estimated that daily consumption of 10 - 35 milligrams is probably safe indefinitely - but to keep in mind that such a high doseage of copper adversely affects zinc nutriture."
Dr. Rath's 330 micrograms is indeed a very small amount of copper.
Jackie