Most kidney stones are calcium stones, usually in the form of calcium oxalate, phosphate, or maleate. Urinary sulfate is a reflection of dietary protein intake, particularly meat, fish, and poultry, which are rich in sulfur-containing amino acids methionine and cysteine. Urinary sulfate can be used to assess dietary protein intake for nutritional purposes. A protein-rich diet has been associated with an increased risk for stone formation. Some patients form stones that are composed of a mixture of magnesium, ammonium, phosphate, and calcium carbonate, which is known as struvite. These stones form as a result of infection with certain types of bacteria that can produce ammonia.CORRECT OPTION IS (D).

Excretion of Calcium Sulphates, Phosphates and Carbonates

Calcium sulphates, phosphates, and carbonates are excreted by the kidneys. Here’s how:

1. Calcium sulphates:
Calcium sulphate is excreted in the form of sulphates (SO4)2- in the urine. The kidneys play a crucial role in regulating the amount of calcium and sulphate in the body. When the body has an excess of sulphate ions, the kidneys increase the excretion of sulphate in the urine, which helps to maintain the balance of these ions in the body.

2. Calcium phosphates:
Calcium phosphate is excreted in the form of phosphate (PO4)3- in the urine. The kidneys play a crucial role in regulating the amount of calcium and phosphate in the body. When the body has an excess of phosphate ions, the kidneys increase the excretion of phosphate in the urine, which helps to maintain the balance of these ions in the body.

3. Calcium carbonates:
Calcium carbonate is excreted in the form of carbonates (CO3)2- in the urine. The kidneys play a crucial role in regulating the amount of calcium and carbonate in the body. When the body has an excess of carbonate ions, the kidneys increase the excretion of carbonate in the urine, which helps to maintain the balance of these ions in the body.

Conclusion:
In summary, calcium sulphates, phosphates, and carbonates are excreted by the kidneys in the form of sulphates, phosphates, and carbonates, respectively. The kidneys play a crucial role in regulating the balance of these ions in the body.