Sodium and Chronic Kidney Disease 

What is sodium?

Sodium is an essential electrolyte in our body and is one of the most basic components of human nutrition. It is the main ingredient of table salt.

I suffer from kidney failure. Should I limit salt?

Yes! It is essential that you limit salt! When suffering from kidney failure, excess amounts of sodium (salt) are accumulated in the body and create several problems.

And what are the benefits of limiting salt (sodium)?

Excess sodium in the body promotes water retention (in an effort of the body to "dilute" it). This is indicated by the swelling first in the legs and gradually in the lung, which leads to shortness of breath. By reducing the amount of sodium, these problems decrease or disappear and are easier to manage. Small amounts of sodium help the kidneys work more "gently" without being forced to over-function (thus being destroyed more quickly), reduce the formation of kidney stones and have a positive effect on the bone structure.

Is salt related to hypertension?

Yes, it is for most patients with hypertension and for almost everyone with hypertension and chronic kidney disease. Reducing salt in your diet leads to lower blood pressure. Converting a high salt diet to a diet with low salt can reduce blood pressure from 4 to 7 mmHg initially. This reduction can be much greater in the years to come with a salt-poor diet, benefiting from cardiovascular complications. Also, less salt makes the antihypertensive treatment to be more effective, meaning that with the same drug dosage, there is a greater reduction in blood pressure in people with low salt intake in their nutrition.

If I do not add salt to my meals is that enough?

No, it is not. Salt is found in many other foods, like all processed foods (canned food, prepared, restaurant and fast food) as well as cheeses, bread (from 290 to 535 mg Na per 100 grams of bread), sausages, additives that improve the flavor of the food or products that help in the preparation of various broths.

 How can I reduce salt in my diet?

  • Remove salt from the table.
  • Cook your food without salt. If it's impossible not to consume salt, add a small amount of salt to your plate (the total amount of salt that you eat will be much less than you normally would if you salted the food at the time of preparation).
  • Avoid foods such as potato chips, shrimps, prepared sauces and other processed foods, which contain large amounts of sodium to be preserved.
  • Gradually reduce the salt you normally put on the various dishes you cook by half, so you will start to like the taste of less salty foods.
  • AVOID salt substitutes, this is especially true for people with renal insufficiency, because they often tend to be potassium chloride (which is dangerous with CKD) or just salt with a different color!
  • Avoid prepared or fast food meals.
  • Read the food labels for salt (sodium). Look for and find low-sodium products on the shelves of food stores.
  • Avoid sausages.
  • Consume small amounts of bread or unsalted (commercially available)

How can I make my food delicious, without salt?

The purpose is to leave salt "aside", not taste. Research has shown that the taste in salt is something acquired and that the desire for salt is less intense after a few weeks of abstaining from it. So, we can use vegetables, spices, onion, garlic, vinegar, lemon instead.

I am on dialysis therapy. How much salt should I consume?

The amount of salt each dialysis patient can take daily does not exceed 60-80 mEq, meaning 3.5-4.5 gr. This corresponds to the amount you receive from foods when you do not add any salt at all.

I undergo dialysis. Why should I limit the salt intake?

Because the consumption of excess salt more than what your nephrologist "allows":

  • increases the feeling of thirst
  • increases the "weight" from one dialysis session to the next one
  • increases blood pressure
  • creates dyspnea

By the Scientific Director Kalliopi Retsa


  1. U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans, 2005. 6. Washington D.C: U.S. Government Printing Office; 2005.
  2. Institute of Medicine. Water, Potassium, Sodium, Chloride and Sulfate. Washington, D.C: National Academy Press; 2004. Dietary Reference Intakes.
  3. U.S. Department of Agriculture, Agricultural Research Service. Nutrient Intakes from Food. Mean Amounts Consumed per Individual, One Day, 2005–2006. [Accessed on: 1/10/2010]. Available:
  4. Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24-hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group. BMJ. 1988; 297:319–328. [PMC free article] [PubMed]
  5. Kalantar-Zadeh K, Kopple JD, Deepak S, Block D, Block G. Food intake characteristics of hemodialysis patients as obtained by food frequency questionnaire. J Ren Nutr. 2002; 12:17–31. [PubMed]
  6. Aviv A. Salt and hypertension: the debate that begs the bigger question. Arch Intern Med. 2001; 161:507–510.[PubMed]
  7. Weir MR. Is it the low-protein diet or simply the salt restriction? Kidney Int. 2007;71:188–190.