The most effective ways to increase urinary citrate are drinking citrus juices daily, reducing salt and animal protein intake, and, when diet alone isn’t enough, taking a prescribed potassium citrate supplement. Normal citrate excretion averages around 640 mg per day, while levels below 320 mg per day are considered low. Low urinary citrate is one of the most common metabolic problems in people who form kidney stones, showing up in 20% to 60% of stone formers.
Why Citrate Matters for Kidney Stones
Citrate is one of the body’s natural defenses against calcium-based kidney stones. It works by binding to calcium in urine before calcium can pair up with oxalate or phosphate to form crystals. Calcium and citrate concentrations are the two most important factors in whether stones form. When citrate is low, calcium is free to combine with other minerals and start the crystallization process that eventually becomes a stone.
Your body’s acid-base balance directly controls how much citrate ends up in your urine. When your blood is more acidic, your kidneys pull citrate back out of the urine and reabsorb it, leaving less behind to do its protective work. Anything that increases your body’s acid load, whether from diet or other conditions, tends to lower urinary citrate. This is the core mechanism behind most of the dietary strategies below.
Drink Citrus Juice Daily
Citrus fruits are natural sources of citrate, but not all citrus drinks raise urinary citrate equally. Orange juice is more effective than lemonade, even though the two contain similar amounts of citrate. The difference comes down to how each drink affects the body’s acid-base chemistry: orange juice provides a stronger alkalizing effect, which raises both urine pH and citrate excretion. Lemonade increases citrate intake but doesn’t shift the body’s overall acid balance as much.
A practical target backed by research is half a cup of lemon juice concentrate diluted in water each day, or the juice of two lemons. This amount has been shown to increase urinary citrate and likely reduce stone risk. If you prefer orange juice, a daily glass achieves even better citraturic results. The key is consistency. A squeeze of lemon once in a while won’t meaningfully change your 24-hour citrate output.
Cut Back on Salt
High sodium intake quietly works against urinary citrate in two ways. A study comparing low-sodium diets (about 1,150 mg of sodium per day) to high-sodium diets (about 6,100 mg per day) found that the high-salt phase dropped urinary citrate by roughly 20%, from 3.14 to 2.52 mmol per day. At the same time, urinary calcium rose significantly, compounding the stone risk.
The mechanism involves bicarbonate. When you eat a lot of salt, your kidneys excrete more bicarbonate to balance sodium levels. Losing that bicarbonate makes the blood slightly more acidic, which triggers the kidneys to reabsorb citrate instead of letting it pass into the urine. So salt doesn’t just increase calcium in urine; it simultaneously removes the citrate that would have kept that calcium in check. Most dietary guidelines for stone prevention recommend keeping sodium below 2,300 mg per day, and ideally closer to 1,500 mg.
Moderate Animal Protein
Meat, fish, poultry, cheese, and eggs all carry a high acid load. When you digest animal protein, the sulfur-containing amino acids generate acid that your body must neutralize. The kidneys respond by pulling citrate back from the urine to help buffer that acid, reducing the amount available to block stone formation. A high animal protein diet also increases urinary calcium and uric acid while lowering urine pH, creating a trifecta of stone-promoting conditions.
This doesn’t mean you need a low-protein diet. The recommended range is 0.8 to 1.0 grams of protein per kilogram of body weight per day, which works out to roughly 55 to 70 grams for most adults. Shifting some of your protein sources from animal to plant-based options also helps, since plant proteins produce less acid and are less likely to suppress citrate excretion.
Eat More Fruits and Vegetables
Fruits and vegetables are naturally alkaline-forming foods. When metabolized, they produce bicarbonate, which shifts your body’s acid-base balance in the direction that promotes citrate excretion. This is the opposite of what animal protein and salt do. You don’t need to follow a rigid alkaline diet; simply increasing your daily servings of produce creates a measurable shift toward higher urinary citrate over time. Citrus fruits pull double duty here, providing both direct citrate and an alkalizing effect.
Stay Well Hydrated
Water intake doesn’t directly raise citrate production, but it dilutes all the substances in your urine, including calcium and oxalate. This reduces supersaturation, the condition that allows crystals to form. Aiming for enough fluid to produce about 2.5 liters of urine per day is a standard target for stone prevention. Adding lemon or lime juice to your water lets you address hydration and citrate at the same time.
Potassium Citrate Supplements
When dietary changes aren’t enough to bring citrate levels into a healthy range, prescription potassium citrate is the standard medical treatment. It works by directly supplying citrate and alkalizing the urine. The therapeutic goal is to raise urinary citrate above 320 mg per day and as close to the normal average of 640 mg per day as possible, while keeping urine pH between 6.0 and 7.0.
Dosing depends on how low your citrate is. For mild to moderate cases, treatment typically starts at a lower dose taken two or three times daily with meals. For severe cases (citrate below 150 mg per day), the starting dose is roughly doubled. Your doctor will check 24-hour urine citrate levels periodically to adjust the dose. The supplement is taken with food to reduce stomach irritation and improve absorption.
Some people can’t tolerate potassium citrate due to gastrointestinal side effects or cost. Sodium bicarbonate (baking soda) is a less expensive alternative that also raises urinary citrate and pH. In short-term studies, it performed similarly to potassium citrate for increasing citrate excretion. However, potassium citrate reduced calcium oxalate supersaturation more effectively. Sodium bicarbonate also adds sodium to the diet, which, as noted above, can work against your goals. It’s generally a better fit for people who form calcium oxalate stones rather than uric acid stones.
How to Know If It’s Working
A 24-hour urine collection is the standard way to measure your citrate output. This test captures everything your kidneys excrete over a full day, giving an accurate picture of citrate, calcium, oxalate, and other stone-related factors. Many experts now suggest that a citrate level below 500 mg per day, not just the traditional 320 mg cutoff, warrants attention and possible treatment. If you’re making dietary changes, repeating the collection after a few months shows whether your efforts are moving the numbers in the right direction.