Is there a relationship between ascorbic acid and kidney stones? Join us to get the answer to this question. Kidney stones are hard deposits that are made up of minerals and salts that form inside the kidneys. Diet, overweight, some medical conditions and some supplements and medications are among the causes of kidney stones. It can affect any part of the urinary tract such as the kidneys and bladder. Often, stones form at the concentration of urine, causing minerals to crystallize and stick together. It is a common disease and its lifetime prevalence is about 10% in countries like the United States. Ascorbic acid, or vitamin C, is an essential nutrient that acts as a factor in several enzymatic pathways; its main food sources include fresh fruits and vegetables.
The daily requirement of ascorbic acid in men is 90 mg and 70 mg in women. Ascorbic acid is not enzymatically broken down in the form of oxalate in the renal tubules in the urine. This oxalate combines with calcium to form calcium oxalate.Men who consume more than 218 mg of ascorbic acid per day have a 31% higher risk of stone formation than people who consume less than 105 mg per day. Normally, 60 mg of ascorbic acid in the form of oxalate is excreted in the urine. In a metabolic study of 24 individuals, 2 g of ascorbic acid per day induced urinary oxalate excretion of approximately 22%. Common calcium oxalate stones can form in acidic urine, however, if a person receives adequate amounts of B vitamins and magnesium, this type of stone will not form Benefits and hamrs of Ascorbic acid.
Calcium phosphate stone is present only in the urinary tract. This stone is very common and not acidic. Ascorbic acid acidifies the urine, thus dissolving phosphate stones and preventing their formation. Acidic urine also dissolves magnesium ammonium phosphate stones, which otherwise require surgery to remove. These are the same struvite stones associated with urinary tract infections. Both infections and stones can be easily treated with high doses of vitamin C.
Research has been conducted on the risk of kidney stones in consumers of ascorbic acid supplements. In this study, one group received vitamin C supplements and the other group received no supplements. In the third group, only multivitamins were taken. The results were compared and found that men who took vitamin C supplements were twice as likely as men who did not take dietary supplements or men who took multivitamins regularly to have kidney stones. The researchers said that both the dose of vitamin C and the combination of nutrients that are swallowed can play an important role in the risk of kidney stones. However, the findings do not prove that the vitamin itself caused the formation of stones. The results should be confirmed by further studies. While the link between high doses of ascorbic acid and regular kidney stones is unclear, some researchers suggest that the recommended intake of vitamin C for adults be increased to 200 mg per day.
Sometimes mega-doses of ascorbic acid are given to patients for health or to treat diseases such as cancer. Ascorbic acid has been shown to have anti-proliferative and anti-tumor effects in cell culture and animal models. But the human carcinogenic benefits have not yet been proven.However, this mega dose can potentially lead to oxalate nephropathy (what is not known is the amount). Evidence has shown that the amount of ascorbic acid ingested or injected is a risk factor for calcium oxalate stone disease, and this risk is associated with the amount of oxalate excreted in the urine. Evidence also shows that the oxidized form of ascorbic acid is unstable and decomposes to oxalate. The synthesis of endogenous oxalate is about 30% to 40% and is considered a residual source of ascorbic acid, which is a risk factor for stone formation. From the above, we concluded that excessive consumption of ascorbic acid supplements can cause kidney stones. But consuming natural ascorbic acid is as necessary and useful for the body as its supplements.