Does vitamin C cause kidney stones?
Anti-Vitamin studies
The Vitamin C Conspiracy
No. The myth of the vitamin C-caused kidney stone is rivaled in popularity only by the Loch Ness Monster. A factoid-crazy medical media often overlooks the fact that William J. McCormick, M.D., demonstrated that vitamin C actually prevents the formation of kidney stones. He did so in 1946, when he published a paper on the subject. (8) His work was confirmed by University of Alabama professor of medicine Emanuel Cheraskin, M.D.. Dr. Cheraskin showed that vitamin C inhibits the formation of oxalate stones. (9)
Other research reports that: "Even though a certain part of oxalate in the urine derives from metabolized ascorbic acid, the intake of high doses of vitamin C does not increase the risk of calcium oxalate kidney stones. . . (I)n the large- scale Harvard Prospective Health Professional Follow-Up Study, those groups in the highest quintile of vitamin C intake (greater than 1,500 mg/day) had a lower risk of kidney stones than the groups in the lowest quintiles." (10)
Dr. Robert F. Cathcart, M.D. said, "I started using vitamin C in massive doses in patients in 1969. By the time I read that ascorbate should cause kidney stones, I had clinical evidence that it did not cause kidney stones, so I continued prescribing massive doses to patients. Up to 2006, I estimate that I have put 25,000 patients on massive doses of vitamin C and none have developed kidney stones. Two patients who had dropped their doses to 500 mg a day developed calcium oxalate kidney stones. I raised their doses back up to the more massive doses and added magnesium and B-6 to their program and no more kidney stones. I think they developed the kidney stones because they were not taking enough vitamin C."
(8) McCormick WJ. Lithogenesis and hypovitaminosis. Medical Record, 1946. 159:7, July, p 410-413.
(9) Cheraskin E, Ringsdorf, Jr. M and Sisley E. The Vitamin C Connection: Getting Well and Staying Well with Vitamin C. New York: Harper and Row, 1983. Also paperback, 1984: New York, Bantam Books. "Vitamin C in the urine tends to bind calcium and decrease its free form. This means less chance of calcium's separating out as calcium oxalate (stones)." [page 213] See also: Ringsdorf WM Jr, Cheraskin E. Nutritional aspects of urolithiasis. South Med J. 1981 Jan;74(1):41-3, 46.