Calcitroic acid

Calcitroic acid is a metabolite of vitamin D that is produced in the kidneys. It is the final product of the vitamin D metabolism pathway and is excreted in the urine. Calcitroic acid is not biologically active, but its production and excretion are important for maintaining the balance of vitamin D in the body.

Metabolism[edit | edit source]

Vitamin D is converted into calcitroic acid through a series of enzymatic reactions. First, vitamin D is converted into calcidiol in the liver. This is then converted into calcitriol, the active form of vitamin D, in the kidneys. Finally, calcitriol is converted into calcitroic acid by the enzyme 24-hydroxylase.

Function[edit | edit source]

Although calcitroic acid is not biologically active, it plays a crucial role in the regulation of vitamin D metabolism. The production of calcitroic acid from calcitriol is a way for the body to remove excess vitamin D. This is important because too much vitamin D can lead to hypercalcemia, a condition characterized by high levels of calcium in the blood, which can cause various health problems.

Clinical significance[edit | edit source]

Abnormal levels of calcitroic acid in the urine can indicate problems with vitamin D metabolism. For example, low levels of calcitroic acid can suggest a deficiency in vitamin D, while high levels can indicate an excess of vitamin D. Measurement of calcitroic acid levels can therefore be used as a diagnostic tool in the evaluation of vitamin D-related disorders.