Kidneys perform the vital function of filtering waste from your body. They also remove extra fluid and acid while maintaining the right balance of minerals, water, and salts in your blood.

If you’re living with chronic kidney disease (CKD), you know how important it is to protect your kidney function. Your doctor might recommend dietary changes to help, such as cutting back on salt.

Table salt (NaCl) is a combination of the minerals sodium and chloride. The human body needs both, but for some people, excess salt puts too much strain on the kidneys.

Table salt is a source of dietary sodium. Sodium can also be found in many foods, such as bread, cold cuts, soups, condiments, sauces, chips, and crackers.

Most of the sodium we eat comes from processed, packaged, and restaurant foods. Only a small amount comes from adding table salt to foods we cook or eat.

Dietary sodium is important. It helps to maintain fluid balance and aids in nerve and muscle function. However, too much sodium can contribute to some common health issues.

The Centers for Disease Control and Prevention (CDC) states that high sodium intake can raise blood pressure. This is because a sodium level that’s too high can interfere with how your kidneys eliminate water.

In addition to being a risk factor for heart disease, high blood pressure is one of the leading risk factors for kidney disease.

Research also links high salt intake with kidney function decline independent of blood pressure.

A study involving 12,126 participants in the general population without CKD found that high salt intake could predict future kidney impairment. While it’s natural for kidney function to slow with age, the study results suggest that a high salt diet can accelerate this decline.

According to the National Kidney Foundation, a healthy diet shouldn’t contain more than 2,300 milligrams (mg) of sodium each day.

How much sodium you should eat may depend on your stage of CKD. Talk with your doctor or a dietitian about the amount of dietary sodium that’s right for you.

It can be helpful to plan for the entire day when deciding what to eat to make sure you don’t exceed your limit.

Pay close attention to portion sizes for packaged food. If the amount you eat is more than what is shown on the can or box, your sodium intake will be higher, too.

Reducing dietary salt intake is an important part of managing CKD. If your kidneys can’t keep up with your salt intake, sodium and fluid can build up in your body. This can cause symptoms like:

  • swollen ankles
  • shortness of breath
  • puffiness
  • increased blood pressure
  • fluid around your heart and lungs

A 2018 meta-analysis involving people living with CKD stages 1 to 4 found that restricting dietary sodium helped to reduce blood pressure, as well as decrease the amount of protein and albumin (a blood protein) in participants’ urine.

Reaching your blood pressure target and reducing urine levels of protein and albumin are important steps to managing CKD.

Switching to a low sodium diet involves a few simple changes to old habits. It can be easier than you might think once you know what to look out for.

Most packaged and canned foods contain sodium, even items that are sweet. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends limiting your intake of these foods to low sodium choices with a daily value (DV) of 5 percent or less.

You can find this information on the Nutrition Facts label on the food package. Foods with a DV of 20 percent or more are considered high in sodium.

You can also look for the words “low sodium,” “reduced sodium,” or “no salt added” on food labels when choosing packaged foods.

In addition to choosing low sodium items, you can cut back on salt even further by:

  • buying fresh food and cooking from scratch
  • limiting canned food, or rinsing it before use
  • using spices instead of salt to season food
  • making homemade sauces
  • limiting salty snacks such as chips or switching to unsalted versions
  • using fresh meat and poultry rather than cured
  • choosing low salt lunch meats
  • making homemade soup

Some salt substitutes can be high in potassium. Potassium is another mineral that can build up in the blood as kidney function declines.

Make sure the salt substitute you choose doesn’t exceed the potassium limit suggested by your doctor. Some people with CKD need to watch their potassium intake to ensure the level in their blood doesn’t get too high.

Choosing a reduced salt diet doesn’t mean you have to miss out on flavor. There are many ways to spice up your meals that won’t overwhelm your kidneys.

Items to limitAcceptable substitutes
table salta doctor-approved salt substitute (have your doctor check the potassium content)
seasoning saltlow sodium or salt-free seasoning
garlic saltgarlic powder or fresh garlic
onion saltonion powder or fresh onion
lemon pepperlemon juice and black pepper
meat tenderizervinegar
soy sauceliquid aminos

The sodium and chloride found in table salt are both important for health — but in moderate amounts.

Healthy kidneys remove excess sodium, but kidneys that are damaged can’t manage salt as effectively.

People living with CKD should reduce their salt intake to prevent sodium from accumulating and causing health issues.

Your dietary sodium intake is something you can manage with some planning. Choose fresh foods when possible. Read foods labels and choose low- or no-sodium alternatives of the packaged food you buy. Try seasoning your food with herbs and spices, rather than table salt.

Making dietary changes is an important part of managing CKD and keeping it from progressing. Reducing sodium in your diet is a simple step you can take to help maintain your kidney health.