Ascorbic Acid And Struvite Staghorn Calculi

There are four kinds of kidney stones. Most kidney stones are made of calcium oxalate or calcium phosphate, but some people develop struvite staghorn kidney stones. Unlike calcium oxalate stones, which can be caused by a high amount of ascorbic acid, struvite stones are caused by a urinary tract infection.

Identification

The word calculi, when used medically, refers to any hard masses such as stones. Struvite staghorn calculi are a type of kidney stone. They are composed of magnesium, ammonium and phosphate, and are called staghorn because the stone can grow large and look like the horns of a stag, another name for a male deer. This type of kidney stone usually is found in women and can reoccur quite fast, according to Marshall Stoler, M.D., professor of urology at the University of California School of Medicine, in "Smith's General Urology."

Causes

Dr. Stoler writes that struvite stones are the result of a urinary tract infection, caused by the Proteus, Providencia, Staphylococci, Pseudomonas, Klebsiella and Mycoplasma bacteria. These bacteria have an enzyme called urease which changes urea to ammonia. Normally, the liver changes ammonia to urea and sends the urea to the kidneys so that it can be excreted in the urine. When the bacteria that cause a urinary tract infection change urea back to ammonia, this changes the environment of the urine so much that magnesium-ammonium-phosphate crystals can form and create struvite kidney stones.

Symptoms and Complications

On the Radiopaedia website, Dr. Frank Gaillard writes about staghorn kidney stones and there's a picture of a stone that clearly shows how it got its name. Most people with this type of kidney stone have pain in their back or side, blood in their urine and a fever. This disorder can lead to an infection within the bloodstream, referred to as septicemia, and cause an abscess and fever. These stones require surgery to ensure that the whole stone and any fragments are removed. Otherwise, a kidney infection can develop and even spread to other organs.

Ascorbic Acid and Kidney Stones

Approximately 85 percent of all kidney stones are calcium stones, per Glenn Preminger, M.D., director of the Comprehensive Kidney Stone Center, on The Merck Manual for Healthcare Professionals website. A high amount of ascorbic acid does not cause struvite staghorn kidney stones, but it can cause calcium kidney stones because ascorbic acid can change to a substance called oxalate, and a high amount of oxalate can result in calcium kidney stones. This is more likely to happen, however, in someone who already has had kidney stones, which is why physicians recommend that those who have had kidney stones should not consume more than 500 mg of ascorbic acid every day.