Last word on Kidney stones and Vitamin C spoken?

Any adverse effects of replacement vitamin C will be discuseed here. Topics include kidney stones, gall stones, oxidation, etc.
We plan to move good discussions from the General Topics forum here for posterity.

Moderator: ofonorow


Last word on Kidney stones and Vitamin C spoken?

Post Number:#1  Post by davidshields » Sat Jul 29, 2006 5:06 pm

First, I am not sure why the Toxicity forum is locked. Are we supposed to post here and let the forum admin move the thread into that forum for archiving purposes?

I was just reading yet another book that claims vitamin C causes kidney stones. I decided to check for the very newest research. In the process, I found something that isn't the newest, but it sounds more conclusive than other studies I have seen: (see abstract below)

It states, based on the Tiselius index, that
These data suggest that vitamin C supplementation may increase ... the risk of calcium oxalate crystallization ....

I checked the existing threads in this forum and didn't see this study mentioned. I didn't see any responses on this forum that would directly refute the study, so I would like to ask about it specifically. If anyone can comment on it, I would appreciate it. I do note that they didn't actually find kidney stone formation, but the study was too short for that and it wasn't designed for that. They did look specifically at oxalate crystallization, however. Can anyone comment on the Tiselius index? Thanks.

Here are the existing threads on this topic in this forum:

Here is the abstract of the study:
Effect of vitamin C supplements on urinary oxalate and pH in calcium stone-forming patients

Background. The contribution of ascorbate to urinary oxalate is controversial. The present study aimed to determine whether urinary oxalate and pH may be affected by vitamin C supplementation in calcium stone-forming patients. Methods. Forty-seven adult calcium stone-forming patients received either 1 g (N = 23) or 2 g (N = 24) of vitamin C supplement for 3 days and 20 healthy subjects received 1 g. A 24-hour urine sample was obtained both before and after vitamin C for calcium, oxalate, magnesium, citrate, sodium, potassium, and creatinine determination. The Tiselius index was used as a calcium oxalate crystallization index. A spot fasting morning urine sample was also obtained to determine the urinary pH before and after vitamin C. Results. Fasting urinary pH did not change after 1 g (5.8 ± 0.6 vs. 5.8 ± 0.7) or 2 g vitamin C (5.8 ± 0.8 vs. 5.8 ± 0.7). A significant increase in mean urinary oxalate was observed in calcium stone-forming patients receiving either 1 g (50 ± 16 vs. 31 ± 12 mg/24 hours) or 2 g (48 ± 21 vs. 34 ± 12 mg/24 hours) of vitamin C and in healthy subjects (25 ± 12 vs. 39 ± 13 mg/24 hours). A significant increase in mean Tiselius index was observed in calcium stone-forming patients after 1 g (1.43 ± 0.70 vs. 0.92 ± 0.65) or 2 g vitamin C (1.61 ± 1.05 vs. 0.99 ± 0.55) and in healthy subjects (1.50 ± 0.69 vs. 0.91 ± 0.46). Ancillary analyses of spot urine obtained after vitamin C were performed in 15 control subjects in vessels with or without ethylenediaminetetraacetic acid (EDTA) with no difference in urinary oxalate between them (28 ± 23 vs. 26 ± 21 mg/L), suggesting that the in vitro conversion of ascorbate to oxalate did not occur. Conclusion. These data suggest that vitamin C supplementation may increase urinary oxalate excretion and the risk of calcium oxalate crystallization in calcium stone-forming patients.
Journal Title
Kidney international (Kidney int.) ISSN 0085-2538 CODEN KDYIA5

2003, vol. 63, no3, pp. 1066-1071 [6 page(s) (article)] (43 ref.)


Post Number:#2  Post by davidshields » Sat Jul 29, 2006 5:31 pm

I found my own answer in the form of Dr. Steve Hickey's reply to Dr. Massey. It says, in part:

"You appear to be relying on the Tiselius Risk Index for your evaluation. Are you aware that this risk index does NOT include the ascorbate molecule?

To put the position simply: ascorbate binds calcium. When there is a large amount of ascorbate, it will compete with oxalate for calcium. To suggest that, in the presence of a large increase in ascorbate, a small increase in oxalate will preferentially bind calcium requires hard evidence.

As far as I am aware, the available evidence shows no risk of stone formation from high intakes of ascorbate. Your paper did not include reference to the direct studies of stone incidence. Indeed the direct evidence refutes the suggestion.
With the greatest of respect, I find your suggestion that vitamin C causes stones unconvincing."
Dr Steve Hicke

The entire conversation can be found here: ... itamin%20C

I'll quote here:
By Bill Sardi

Do vitamin C supplements induce kidney stones? The National Library of Medicine lists 64 reports concerning this topic. Some reports say no, others say yes, there is an increased risk for kidney stones with high-dose vitamin C. Recently, Linda Massey, a researcher at Washington State University, suggested 500 milligrams of vitamin C/day is the maximum “that would be considered safe” in regards to vitamin C and kidney stones. The Council for Responsible Nutrition then replied to Massey’s letter and concludes any alleged risk for kidney stones from vitamin C consumption would only be in a small group of men. Steve Hickey, PhD, of Manchester, England, then responded to Massey’s claim with a letter [which Bill's site, at the link I gave above, makes available as a PDF file]

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No Clinical Studies

Post Number:#3  Post by ofonorow » Sun Jul 30, 2006 10:57 am

First, yes, we will move reports of toxicity from the general discussion to the toxicity forum.

Second, there a no clinical, placebo controlled, double blind studies in guinea pigs, humans or other non-C producing species that show increased vitamin C produces kidney stones.

Dr. Robert Cathcart's more than 30-years experience (no kidney stones in his patients) indicates that there is something highly protective in high vitamin C regarding kidney stones.

And again, for people with acidic urine, there is a possibility that vitamin C might aggravate a propensity to form stones (we doubt it) and those people should take sodium ascorbate, or enough bicarb that the urine is less acidic. From Paulings review, we can infer that stones form in acidic or alkaline urine, not neutral urine.
Owen R. Fonorow, Orthomolecular Naturopath

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