What Is Potassium Citrate?
The chemistry of potassium citrate, its natural sources, the mechanism by which it inhibits kidney stone formation, and its industrial applications.
Definition and chemistry
Potassium citrate is a white, crystalline powder with the chemical formula K₃C₆H₅O₇. It dissolves readily in water and in some organic solvents, and has a sweet, faintly saline taste. It is the potassium salt of citric acid.
It is a versatile compound used in the food industry, in pharmaceuticals and in personal care products. As a food additive it carries the code E332.
- Chemical name
- Tripotassium citrate
- Formula
- K₃C₆H₅O₇
- Molecular weight
- 306.4 g/mol (anhydrous)
- Appearance
- White, crystalline, hygroscopic powder
- Solubility
- Freely soluble in water
- Food additive code
- E332
Where it occurs in nature
Potassium citrate does not occur directly in this salt form. The citric acid required to produce it, however, is found naturally across a wide range of fruits and plants. Citrus fruits such as lemon, orange, grapefruit and mandarin are the principal sources, while strawberry, kiwi and pineapple are also rich in citric acid.
Citric acid obtained by processing and concentrating these fruits is converted into its potassium salt form and used in the manufacture of potassium citrate.
Mechanism of action
The role of potassium citrate in preventing kidney stone formation is explained by its inhibitory action on calcium stones in particular:
- Alkalinisation of urine: formation of stone types that arise in an acidic environment is inhibited.
- Binding of calcium: citrate complexes with calcium, preventing calcium and oxalate ions from crystallising.
- Inhibition of crystallisation: calcium oxalate stones require ions to come together at a certain concentration; citrate makes this association more difficult.
- Inhibition of nucleation and aggregation: citrate impedes the formation of nuclei and their coalescence into larger structures.
- Action on aggregates: it binds to aggregates that have already formed and limits their growth.
Areas of use
Food industry
Used as an acidity regulator, stabiliser and flavouring agent. It is preferred in soft drinks, jellies, ice creams, cheeses and chocolate manufacture, and plays a part in adjusting the pH of these products.
Pharmaceutical sector
By regulating the body's acid–base balance it assists in alkalinising the urine, thereby reducing the risk of stone formation. It is also used to correct potassium deficiency.
Personal care products
It appears in shampoos, toothpastes and skin care products as a pH regulator and buffering agent, contributing to the maintenance of the skin's natural pH balance.
Effects on health
Potassium citrate is generally a safe and well-tolerated compound. However, because it can lead to imbalances in potassium levels, it should be used under medical supervision, particularly by people with impaired renal function. Excessive intake may cause stomach upset, nausea and diarrhoea.
This page is for information only. It is neither product promotion nor a treatment recommendation. For any health concern, or before prolonged use, consult your doctor or pharmacist.
Frequently asked questions
What is potassium citrate used for?
It serves three main fields: as an acidity regulator in food (E332), as an active substance that alkalinises urine and inhibits kidney stone formation in medicine, and as a pH buffer in personal care products. Medicinal use requires physician assessment.
What should be considered when using potassium citrate?
Medicinal potassium citrate is used under physician supervision, as it affects potassium levels and may accumulate in people with reduced kidney function. Consult your physician or pharmacist before combining it with any medicine.
What is potassium citrate?
Potassium citrate is the potassium salt of citric acid. It is a white, crystalline powder with the formula K₃C₆H₅O₇ that dissolves readily in water. As a food additive it carries the code E332, and it is also used in pharmaceuticals and personal care.
Where does potassium citrate occur in nature?
Not directly in this salt form. The citric acid needed to produce it occurs naturally in citrus fruits such as lemon, orange, grapefruit and mandarin, as well as in strawberry, kiwi and pineapple.
How does potassium citrate inhibit kidney stone formation?
Five mechanisms act together: it alkalinises the urine, binds calcium so that calcium and oxalate ions cannot crystallise, makes it harder to reach the ion concentration crystallisation requires, inhibits nucleation and aggregation, and binds to existing aggregates to limit their growth.
What does potassium citrate do in food?
It acts as an acidity regulator, stabiliser and flavouring agent, and is used to adjust pH in soft drinks, jellies, ice creams, cheeses and chocolate.
Does potassium citrate have side effects?
It is generally well tolerated. It can nevertheless disturb potassium balance, and excessive intake may cause stomach upset, nausea and diarrhoea. Medical supervision is required for people with impaired renal function.
Aymed İlaç Sanayi manufactures in the urinary system field, including products containing potassium citrate. For the product list see Medicines and Consumer health.