Sodium is important to human health, but eating too much can increase your risk of developing some diseases. Learn more about sodium, and how a high-sodium diet can affect your health.

What is sodium?

Sodium is a nutrient that's essential to maintaining human health. It:

  • regulates water balance
  • maintains blood volume
  • controls muscle and nerve function
  • helps to maintain our body temperature.

People must eat small amounts of sodium regularly to stay healthy.

Sodium in food

Sodium is added to foods to enhance flavour, preserve food, and improve processing. About 90% of sodium in our diet comes from salt (sodium chloride).

What's the difference between salt and sodium?

Salt is 40% sodium and 60% chloride – so a food's sodium and salt levels will not be the same. For example, a food with 2.5 grams of salt would have 1 gram of sodium.

It's the sodium in salt that can be bad for your health.

Sodium and health

People who eat too much sodium have a greater risk of developing diseases of the heart, blood vessels, and kidneys.

Recommended intake

The New Zealand Ministry of Health recommends adults and older children (14 years and above) should have no more than 1,600 to 2,300 milligrams of sodium a day. That's equivalent to 4 to 6 grams of salt (a teaspoon is 5 grams). Children need less sodium.

This suggested intake is still more sodium than we need for basic health – which is between 460 and 920 mg.

The Ministry of Health recommends that New Zealanders eat less sodium to lower blood pressure and reduce their risk of cardiovascular disease and stroke.

How to eat less sodium

The food industry has been reducing salt in many products to bring down sodium levels. For example, sodium levels in bread, cheese, and milk were lower in the latest New Zealand Total Diet Survey than in previous surveys.

However, sodium levels are still high in some foods. To reduce your intake, the Ministry of Health recommends:

  • choosing wholefoods or those that are less processed. These are typically lower-sodium. Most sodium is found in processed foods, and many of these may not taste salty – for example, breakfast cereals.
  • using less salt when cooking, or on top of finished meals.

Avoid high-sodium foods

Foods with more than 600 milligrams of sodium per 100 grams are considered high-sodium foods. These include:

  • savoury snacks (such as crisps)
  • processed meats like bacon, sausages, ham and canned corned beef
  • sauces – such as tomato and soy sauce
  • fast foods.

Check food labels

Nutrition panels on foods list the amount of sodium in each serving and per 100 grams. Use this information to compare similar foods and make the best choice.

Food labels may also make claims about a product’s sodium levels. If the label says:

  • low sodium or low salt– the product must have no more than 120 milligrams of sodium per 100 grams
  • reduced sodium/salt – the product must have at least 25% less sodium/salt than a comparable food.

Find out more

Who to contact

If you have questions about sodium in food, email

Last reviewed: