Citrate helps inhibit the formation of calcium oxalate urinary stones: it can chelate with calcium to form a soluble salt.The calcium cannot accordingly bond with the oxalate to form a stone. Potassium citrate administered orally is also an alkalinising agent (it increases the urine pH). Urine alkalinisation reduces the excretion of calcium in the urine, increasing the excretion of citrate.
The alkalinising effect of potassium citrate should be managed with care, as it can also induce the risk of stone formation in alkaline urine: struvite stones and calcium phosphates stones.
The alkalinising effect of potassium citrate is interesting in the fight against other types of stones that can develop in acidic pH environments, ammonium urate stones (alkaline urine containing low concentrations of ammoniac and ammonium ions) and cystine stones. Calcium oxalate stones are not sensitive to urine pH, but alkalinisation indirectly permits the excretion of calcium in the urine.
Potassium citrate is a mineral salt.