In response to the article [ vitamins explored Vit C ] on the harmfulness of Vit C inre kidney stones. The article on Vitamin C regarding its benefits in ridding kidney stones and its overall antiviral/antibacterial effects with megadoses, by Robert McHeffey.

There are five types of kidney stones:
1. Calcium phosphate stones are common and easily dissolve in urine acidified by Vitamin C.

2. Calcium oxalate stones are also common but they do not dissolve in acid urine.

3. Magnesium ammonium phosphate (struvite stones) are much less common, often appearing after an infection. They dissolve in vitamin C acidified urine.

4. Uric acid stones result from a problem metabolizing purines (the chemical base of adenine, xanthine, theobromine [in chocolate] and uric acid). They may form in a condition such as gout.

5. Cystine stones result from a hereditary inability to reabsorb cystine. Most children's stones are this type, and these are rare.

The Role of Vitamin C in Preventing and Dissolving Kidney Stones:
The very common calcium phosphate stone can only exist in a urinary tract that is not acidic.

Ascorbic acid (vitamin C's most common form) acidifies the urine, thereby dissolving phosphate stones and preventing their formation. Acidic urine will also dissolve magnesium ammonium phosphate stones, which would otherwise require surgical removal. These are the same struvite stones associated with urinary tract infections. Both the infection and the stone are easily cured with vitamin C in large doses. BOTH are virtually 100% preventable with daily consumption of much-greater-than-RDA amounts of ascorbic acid. Think grams, not milligrams! A gorilla gets about 4,000 mg of vitamin C a day in its natural diet. The US RDA for humans is only 60 mg. Someone is wrong, and I don't think it's the gorillas.

The common calcium oxalate stone can form in an acidic urine whether one takes vitamin C or not. However, if a person gets adequate quantities of B-complex vitamins and magnesium, this type of stone does not form. Any common B-complex supplement twice daily, plus about 400 milligrams of magnesium, is usually adequate. Ascorbate (the active ion in vitamin C) does increase the body's production of oxalate. Yet, in practice, vitamin C does not increase oxalate stone formation. Drs. Emanuel Cheraskin, Marshall Ringsdorf, Jr. and Emily Sisley explain in The Vitamin C Connection (1983) that acidic urine or slightly acidic urine reduces the UNION of calcium and oxalate, reducing the possibility of stones. "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)

Also, the diuretic effect of vitamin C reduces the static conditions necessary for stone formation in general. Fast moving rivers deposit little silt. Furthermore, you can avoid excessive oxalates by not eating (much) rhubarb, spinach, or chocolate. If a doctor thinks that a person is especially prone to forming oxalate stones, they may take their vitamin C in a buffered form. Instead of ascorbic acid, they might use vitamin C as non-acidic "ascorbate."

Magnesium, calcium, sodium and potassium ascorbates are all non-acidic. Other "buffered" vitamin C preparations are usually made from ascorbic acid mixed with powdered limestone (Dolomite). Linus Pauling says you can take a little sodium bicarbonate with ascorbic acid to neutralize it.