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There are many varieties of fish. While all fish provide excellent high-quality protein for your diet, some fish provide higher amounts of omega-3 fatty acids. Our bodies do not produce omega-3 fatty acids, so we have to get them from our diet. 

Why is fish a superfood?

Fish is a good source of protein without being high in saturated fat– Just a 3 oz portion of fish (the size of a deck of cards) provides an average of 20 grams of protein.

Other reasons why fish is considered a superfood include:

  • Fish is loaded with vitamins such as D and B2 (riboflavin). 
  • Fish is a great source of minerals, calcium, phosphorus, iron, zinc, iodine, magnesium, and potassium. 
  • Fatty fish, such as salmon, are some of the best sources of omega-3 fatty acids. These omega 3-fatty acids are packed with benefits for your heart, brain, eyes, inflammation, and your overall health. 

Fish and kidney disease

The amount of potassium and phosphorus in fish varies depending upon the type of fish (see the chart below). The amount of potassium and phosphorus you can have each day will depend on your stage of kidney disease and/or the type of dialysis you receive.  

Chronic kidney disease (CKD) and transplant

Most people with kidney disease or transplants do not have to limit fish.  

When you reach the later stages of kidney disease your doctor may want you to limit the amount of protein you eat.  Eating fish can still be a great option but you might need to eat smaller portions.  Talk to your doctor or to a kidney dietitian to find out your individual needs.  

With a transplant, you will want to avoid raw or undercooked fish as it can pose an increased risk of foodborne illness (also known as food poisoning). Transplant patients are at higher risk since they take immunosuppressive medications or “anti-rejection medications” to protect the new transplanted kidney. 

Hemodialysis (3 times a week) and daily home or nocturnal hemodialysis/peritoneal dialysis

People on dialysis have increased protein needs. Include fish two times per week as a great lean protein option and a way to help boost intake of omega-3 fatty acids. The potassium and phosphorus content of fish varies (see the chart below). Choose fresh fish when possible because it is lower in sodium. Canned fish can be high in sodium.  Always talk to your kidney dietitian to find out how you can include fish in your diet. 

Kidney stones

Eating fish will not have an effect on forming kidney stones.

Some concerns

Larger fish like tuna and sharks may have high mercury concentrations. See list of seafood, mercury levels and maximum serving recommendations per week at

Cooked fish nutrition facts

Food Potassium mg/100gm (3.5oz) serving Phosphorus mg/100gm  (3.5oz) serving Sodium mg/100gm (3.5oz) serving 
Black cod/ Sablefish* 459 215 72
Bluefin tuna* 323 326 50
Catfish 366 247 119
Flounder 197 309 363
Haddock 351 278 261
Herring 542 292 95
Mackerel* 558 318 203
Perch 344 257 79
Pollock 456 283 110
Rainbow trout 450 270 61
Salmon* 439 313 90
Striped bass* 328 254 88
Sardines* (canned) 397 490 307
Tilapia 380 204 56
Tuna light (canned in water) 176 137 219
White fish 434 285 132

*Good source of omega-3 fatty acids
Additional nutrition information can be found at the United States Department of Agriculture (USDA) website


Baked salmon in foil

Servings – about 8 - 3oz servings


  • ½ cup olive oil
  • 2 ½ tablespoons lemon juice, or more to taste 
  • 5 cloves garlic, minced or pressed through a garlic press
  • 1 tablespoon brown sugar
  • 1 teaspoon dried oregano
  • 1 teaspoon dried thyme
  • freshly ground black pepper to taste
  • aluminum foil
  • 1 teaspoon olive oil
  • 1 (2 pound) salmon fillet 
  • ¼ cup chopped fresh parsley
  • 1 lemon, sliced


  1. Preheat the oven to 375°F (190°C).
  2. Combine 1/2 cup olive oil, lemon juice, garlic, brown sugar, oregano, thyme, and pepper in a bowl. 
  3. Place a large piece of aluminum foil on a baking sheet and brush with olive oil. Place salmon in the middle of the foil, skin-side down. Drizzle with olive oil mixture. Fold up the edges of the foil over the salmon to create a packet, making sure to seal the edges. 
  4. Bake in the preheated oven until the fish flakes easily with a fork, 20 to 25 minutes, until the internal temperature is 145°F. If your salmon fillet is very thick, it can take longer. Garnish with fresh parsley and lemon slices.

Nutrition facts per serving

Calories 285
Fat 22 g
Saturated fat 4.5 g
Polyunsaturated fat
3.8 g
Monounsaturated fat 13.6 g
43 mg
Sodium 44 mg
Total carbohydrate 4 gm
Dietary fiber 0 g
Total sugar 2 g
Protein 17 g
Potassium 312 mg
Phosphorus 250 mg

Recipe adapted from

Want to save this information for later?

For more information, contact National Kidney Foundation

Toll-free helpline: 855.NKF.CARES or email

*This content is provided for informational use only and is not intended as medical advice or as a substitute for the medical advice of a healthcare professional.

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