Sodium appears as a risk factor across the stone literature with unusual consistency, and a low-sodium diet is part of the dietary pattern a 2026 systematic review found may reduce recurrence. The DASH diet — designed for blood pressure, not stones — keeps turning up in the protective column. And unlike most dietary advice, sodium is something your own 24-hour urine test measures directly.
What the reviews found
The 2026 systematic review in Annals of Internal Medicine, covering 31 studies of which 26 were randomised trials, listed among the things that may reduce recurrence in adults with calcium stones: a diet with normal to high calcium, low protein and low sodium. The review rated that conclusion as low strength of evidence — its own assessment, and worth carrying with the finding.
The 2024 umbrella review, assessing 17 meta-analyses across 46 candidate risk factors, identified dietary sodium among the suggestive causal risk factors for stone formation, alongside central obesity, type 2 diabetes, gout, fructose intake, and higher ambient temperatures.
The same review placed the DASH diet among the suggestive protective factors.
Why salt, mechanically
A review dedicated to salt and stones describes the link: higher salt intake is associated with hypercalciuria — more calcium in the urine — and hypocitraturia — less citrate. Those are two of the main risk factors for calcium stone formation, and salt pushes both the wrong way at once.
The kidney handles sodium and calcium together. Excrete more sodium and you tend to excrete more calcium with it. That is the short version of a more complicated tubular story, but it is the part that matters here.
Why the DASH diet keeps appearing
DASH — Dietary Approaches to Stop Hypertension — was designed to lower blood pressure. It is high in fruit, vegetables and low-fat dairy, and low in sodium and red meat.
Read that against the 2026 review's list and the overlap is obvious: it is low in sodium, low in animal protein, and not low in calcium — the dairy is the point. It happens to match the pattern the stone literature keeps arriving at, without having been designed for it.
That convergence is why it appears in the protective column of the umbrella review, rather than because anyone set out to test DASH as a stone treatment.
The thing that makes sodium different
Almost everything in stone prevention is hard to verify. You change something, and a year later you either formed a stone or you did not.
Sodium is one of the exceptions. Urinary sodium is measured on a standard 24-hour urine collection. So is calcium, and so is citrate — the two things salt is thought to move.
That means this is one of the few dietary changes where you can find out whether it did anything, rather than guessing. Collect, change what you eat, collect again, compare. That is what the organiser on this site is built to make easy.
What this page will not do
Give you a number. Sodium targets depend on your blood pressure, your medication, your kidney function, and your own measured urinary sodium and calcium. Someone on a diuretic is in a different situation from someone who is not.
What is uncontroversial enough to say: most sodium in a Western diet comes from processed and restaurant food rather than the salt cellar, so if this is a conversation you plan to have, it is a conversation about what you buy rather than what you sprinkle.