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Preventing kidney stones

Your wee (urine) is affected by what you eat and drink. If you've had kidney stones before, following the tips below will reduce your risk of getting them again.

Drink plenty of fluid, especially water

Drink at least 10 to 12 cups of fluid each day. Water is best.

Some juices such as orange, grapefruit and apple juice have been shown to lower your risk of forming stones. But these are high in sugar so have no more than 1 cup (250 ml) per day.

Read How to get enough to drink for tips about making sure you get enough fluid.

Avoid fizzy and sugary drinks.

Eat less salt (sodium)

Salt increases the amount of calcium in your wee. This can cause stones. About 75% of the salt we eat comes from processed and packaged foods.

Look for foods labelled as salt-reduced, no added salt or low sodium. You can also check food labels for sodium content. Read the nutrition information panel on food packets and choose food with less than 120 mg of sodium per 100 g of food.

Use herbs, spices and other seasonings instead of salt in cooking and at the table.

Eat fresh foods such as fruit, vegetables, eggs, meat, fish, unsalted nuts and milk. They generally have much less salt than processed foods.

See How to reduce your salt intake for more information about what foods are high in salt and more tips to reduce the amount of salt you eat.

Eat plenty of calcium-rich foods

Some people believe having too much calcium causes stones. Some types of calcium supplements may cause stones. But there is no proof that calcium-rich foods do. In fact, if you do not eat enough calcium-rich foods you're more likely to form stones.

Milk and milk products such as cheese and yoghurt are the best sources of calcium.

See Eating well for strong healthy bones for information about how much milk and milk products you should eat and about other good sources of calcium.

Choose small servings of animal protein foods

Too much animal protein such as meat, chicken, fish and eggs, will make your wee more acidic and more likely to form stones. Limit the amount you eat to one to two servings each day. A serving is a piece of meat, chicken or fish the size and thickness of the palm of your hand, or two eggs.

Plant proteins such as legumes (dried beans, peas and lentils), tofu, nuts and seeds do not make your wee acidic. Have meatless meals made from legumes or tofu more often. See the Healthy Food Guide for a selection of nutritious and tasty recipes and meal ideas.

Oxalate-rich foods

In the past, people with kidney stones were told to avoid oxalate-rich foods. We thought these foods increased the amount of oxalate in wee causing stones. But we now know most oxalate found in wee is made in the body and doesn't come from what we eat. How much fluid, calcium, sodium and protein you have is more important than how many oxalate-rich foods you eat.

If you have very high amounts of oxalate in your wee, you may need to limit some oxalate-rich foods such as spinach, silverbeet and rhubarb. Also, large amounts of vitamin C can increase the amount of oxalate in your urine.

If you want to take a vitamin C supplement, take less than 1000 mg per day. The amount of vitamin C in foods is not enough to be a problem.

Written by HealthInfo clinical advisers. Last reviewed April 2023.

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Page reference: 245693

Review key: HIKIS-19017