Condition: Nierstenen

199 people with a first idiopathic calcium stone were randomized to drink enough to keep urine output above 2 liters a day or to no specific advice, and followed 5 years. Recurrence was 12.1% in the high-fluid group against 27.0% in the control group, and the average time to a new stone was longer, 38.7 against 25.1 months. Measured in: 199 adults after a single idiopathic calcium stone, no drug treatment, followed for 5 years in Parma, Italy.. One single-center trial in first-time stone formers, so it speaks best to someone early in the course, not to a person with many past stones. It was open-label, which a water study has to be, and it measures what people who agreed to drink more achieved, not a pill taken on schedule.

120 men with recurrent calcium-oxalate stones and high urinary calcium were randomized for 5 years to a diet with normal calcium (about 1,200 mg/day) plus reduced salt and animal protein, or to the traditional low-calcium diet (about 400 mg/day). Relapses were 12 of 60 on the normal-calcium diet against 23 of 60 on the low-calcium diet, a relative risk of 0.49 (95% CI 0.24 to 0.98). Urinary oxalate fell on the normal-calcium diet and rose on the low-calcium one. Measured in: 120 men with recurrent calcium-oxalate stones and idiopathic hypercalciuria, followed 5 years.. This is the trial that overturned the old low-calcium advice, and it studied men with one specific stone chemistry, calcium oxalate with high urinary calcium. Cutting dietary calcium lets more oxalate cross the gut and reach the urine, which is the mechanism it exposed. The comparison was against a low-calcium diet, not against eating freely.

416 people with recurrent calcium stones were randomized to hydrochlorothiazide at 12.5, 25 or 50 mg daily or to placebo and followed a median of 2.9 years. A stone recurrence occurred in 59% on placebo and in 59%, 56% and 49% across the three doses, with no significant dose-response and no clear separation from placebo. Measured in: 416 adults with recurrent calcium-containing stones, Switzerland, median 2.9 years.. Thiazides do lower urinary calcium and older, smaller trials suggested they cut recurrence, which is why guidelines recommend them. This large, well-run trial did not confirm that, so it is an open question, not a settled answer, and a prescriber weighs it case by case.

A systematic review of 28 randomized trials for an American College of Physicians guideline found that in people with one past calcium stone, increased fluid intake roughly halved recurrence (relative risk 0.45) and cutting soft drinks lowered it (RR 0.83). In people with several past stones, most already drinking more, adding a thiazide (RR 0.52), citrate (RR 0.25) or allopurinol (RR 0.59) on top of fluid reduced recurrence further, with allopurinol's benefit limited to those with high uric acid. Measured in: Adults with calcium stones, pooled across randomized and controlled trials in the review.. The review pre-dates the 2023 NOSTONE trial, which did not confirm the thiazide benefit, so the fluid and citrate conclusions have held up better than the thiazide one. It sets the order of operations: fluids first, targeted drugs second.

Across 45,619 men followed 4 years, men eating the most dietary calcium had a lower risk of a symptomatic stone than men eating the least, relative risk 0.66 (95% CI 0.49 to 0.90) after adjustment. In the same cohort higher animal-protein intake raised risk (RR 1.33), while higher potassium (RR 0.49) and higher fluid (RR 0.71) lowered it. Measured in: 45,619 male health professionals aged 40 to 75 with no history of stones at baseline, followed 4 years.. What could explain it instead: Men who eat more dairy calcium and produce and less meat tend to differ in overall diet quality, weight, and activity, any of which affects stone risk. The study adjusted for many of these, but a healthier-eater pattern cannot be fully separated from the calcium itself.. An observational cohort, so it shows a pattern, not proof, but it points the same way as the later diet trials, which is why it carries weight.

Among 91,731 women followed 12 years with 864 stones, those in the highest fifth of dietary calcium had a lower risk than the lowest fifth (RR 0.65, 95% CI 0.50 to 0.83), while women taking calcium supplements had a slightly higher risk than non-users (RR 1.20, 95% CI 1.02 to 1.41). Higher fluid (RR 0.61) and potassium (RR 0.65) lowered risk; more sucrose (RR 1.52) and sodium (RR 1.30) raised it. Measured in: 91,731 women in the Nurses' Health Study, followed 12 years.. What could explain it instead: Women who take calcium pills differ from those who do not in age, bone health, and reason for supplementing, and supplement users may take them apart from meals. These differences, not the calcium alone, could carry part of the higher risk seen with pills.. The split between food calcium helping and pill calcium not helping fits timing: calcium eaten with a meal binds oxalate in the gut before it reaches the urine, whereas a supplement taken away from food does not. It does not mean calcium supplements must be avoided, only that they are best taken with meals.

Across three large cohorts with 4,827 stones, a BMI of 30 or more, compared with 21 to 22.9, carried a relative risk of 1.33 in men, 1.90 in older women and 2.09 in younger women. Gaining more than 35 lb (about 16 kg) since early adulthood raised risk by 39% in men and 70 to 82% in women. Measured in: Men in the Health Professionals Follow-up Study and women in Nurses' Health Studies I and II, 46 years of combined follow-up.. What could explain it instead: People with higher BMI differ in diet, especially sugar, salt and animal protein, and in fluid intake, all independent stone risks. The analysis adjusted for these, but weight tracks with a whole cluster of habits that raise risk.. Obesity changes urine chemistry, raising calcium, oxalate and uric acid and lowering pH, so the link is biologically plausible as well as statistical. Losing weight is expected to help for the same reasons, though these cohorts measured risk with weight, not the effect of losing it.

Among 194,095 people with 4,462 stones, the highest intake of sugar-sweetened cola carried a 23% higher risk of a stone than the lowest, and sugar-sweetened non-cola drinks a 33% higher risk. In the same analysis coffee, tea, wine, beer and orange juice were each linked with lower risk. Measured in: 194,095 participants pooled from three US cohorts, median follow-up over 8 years.. What could explain it instead: Heavy soda drinkers differ in weight, total diet and activity from people who drink coffee or juice, and those differences drive stone risk on their own. Adjustment reduces but does not remove this.. Not every fluid counts the same. The old advice to 'drink more of anything' is too blunt: sugary drinks, especially those sweetened with fructose, track with more stones, while several unsweetened drinks track with fewer.

Across three cohorts with 5,645 stones, people eating most like the DASH pattern (rich in fruit, vegetables, nuts, legumes, low-fat dairy and whole grains, low in salt, sugary drinks and red meat) had a lower risk than those eating least like it: relative risk 0.55 in men, 0.58 in older women and 0.60 in younger women. The benefit held even in people with lower calcium intake. Measured in: 241,766 adults across the Health Professionals Follow-up Study and Nurses' Health Studies I and II, up to 18 years of follow-up.. What could explain it instead: People who eat a DASH-style diet tend to be leaner, more active and more health-conscious overall. The study adjusted for BMI and fluid, but the dietary pattern still travels with a healthier life.. DASH bundles most of the single levers, more produce and potassium, more dairy calcium, less salt, sugar and meat, into one pattern, which is why the effect is larger than any one change alone. It is a whole way of eating, not a supplement.

57 people with recurrent calcium stones and low urinary citrate were randomized to potassium citrate (30 to 60 mEq/day) or placebo for 3 years. In the treated group new stone formation fell from 1.2 to 0.1 stones per person per year and 13 of 18 (72%) went into remission, while the placebo group stayed at about 1.1 per year with only 4 of 20 (20%) in remission. Measured in: 57 adults with active recurrent calcium stones and hypocitraturia, 3-year randomized trial.. This works for a specific group, people whose 24-hour urine shows low citrate, which is why knowing your urine chemistry matters before reaching for it. It is a small trial, and the food route to the same end, citrus and produce, raises urinary citrate too.

Across 197,271 people with 6,245 stones, high total vitamin C intake was linked with more stones in men (1,000 mg/day or more versus under 90, hazard ratio 1.43, 95% CI 1.15 to 1.79) and supplemental vitamin C at 1,000 mg/day or more with a hazard ratio of 1.19 (95% CI 1.01 to 1.40). No significant association appeared in women, and dietary vitamin C from food was not linked with stones in either sex. Measured in: 40,536 men and 156,735 women in three US cohorts, median follow-up about 11 years.. What could explain it instead: High-dose supplement users differ from non-users in health beliefs and other habits. The analysis adjusted for BMI, thiazide use and diet, and the food-versus-pill split argues for a real dose effect, but residual confounding remains possible.. The body turns some vitamin C into oxalate, which is the plausible route to more calcium-oxalate stones, and it shows up with supplements, not food because supplement doses run far higher. Vitamin C from fruit and vegetables carried no risk.

Across 217,883 people with 4,982 stones, those in the highest fifth of caffeine intake had a lower risk of a stone than the lowest fifth: 26% lower in men, 29% and 31% lower in the two women's cohorts. In a urine substudy, more caffeine went with higher urine volume and lower calcium-oxalate supersaturation. Measured in: 217,883 adults across three US cohorts, median follow-up over 8 years.. What could explain it instead: Coffee and caffeine drinkers differ from abstainers in weight and diet. The study adjusted for fluid intake and BMI, and the supporting urine chemistry strengthens the case, but this remains an association.. The benefit held even in people who drank little caffeinated coffee, which points to caffeine itself, not only the fluid. It is a reason not to fear coffee, not a reason to load up on caffeine, and very high intake carries its own downsides.

In rats given a chemical that drives calcium-oxalate crystals to form, total flavonoids of Desmodium styracifolium reduced crystal deposition in the kidney and lessened kidney-cell injury compared with untreated animals. Measured in: A hydroxy-L-proline rat model of calcium-oxalate urolithiasis.. Jin Qian Cao (Desmodium, 'golden coin grass') is the herb Chinese medicine reaches for most in stone disease, and the traditional use is centuries old. The modern support so far is laboratory and animal work plus small human series, not the large human trials the dietary levers have, so it belongs alongside them, not ahead of them, and herbal products sold online can be mislabeled or adulterated.

In a double-blind single-center trial, 80 adults with acute renal colic from a ureteric stone received either acupuncture at SP6 and SP9 or an intramuscular injection of the anti-inflammatory lornoxicam. The short-term response rate was about 85% (33 of 39) with acupuncture against 61% (25 of 41) with the drug (P<0.001), and pain fell faster with acupuncture. Side effects were uncommon and similar in both groups (2.6% versus 7.3%, not a significant difference). Measured in: Adults presenting with acute renal colic from a ureteric stone, single randomized trial.. This is about controlling the pain of a stone already on the move, not about dissolving or preventing stones. It is a single trial and acupuncture pain studies are hard to blind. It sits alongside standard pain relief, and severe colic with fever or no urine still needs urgent care.