This randomized and controlled study compared the effects of fresh lemon juice (60 mL twice daily) and no supplement on the recurrence of kidney stones in patients with calcium oxalate nephrolithiasis. 203 patients have been enrolled. Time to stone recurrence at 2 years of follow-up was the primary outcome.

At the end of follow-up, a trend to decrease in the incidence of kidney stone has been noted in the lemon juice group (HR = 0.62, 95% CI: 0.35, 1.07, p = 0.089). However, a significant reduction in the patient adherence to lemon juice ahs been noted (68% at 1 year, 48% at 2 years). An analysis after 1 year showed that lemon juice was able to reduce significantly the incidence of stone recurrence (HR = 0.43, 95% CI: 0.20, 0.89, p = 0.028). These effects were associated with a reduction in 24 h urinary sodium excretion.

In conclusion, fresh lemon juice may be effective to prevent the formation of kindey stones, but long-term effect may be limited due to low adherence to lemon juice intake.

Ruggenenti P, Caruso MR, Cortinovis M, Perna A, Peracchi T, Giuliano GA, Rota S, Brambilla P, Invernici G, Villa D, Diadei O, Trillini M, Natali G, Remuzzi G. Fresh lemon juice supplementation for the prevention of recurrent stones in calcium oxalate nephrolithiasis: A pragmatic, prospective, randomised, open, blinded endpoint (PROBE) trial. EClinicalMedicine. 2021 Dec 14;43:101227.