Cod is a moderate-potassium fish. A standard 3-ounce cooked serving of Atlantic cod contains roughly 207 mg of potassium, which is far below the threshold most nutrition guides use to classify a food as “high potassium” (typically 300 mg or more per serving). For most people, cod fits comfortably into a balanced diet without any potassium concerns, and even those on potassium-restricted diets can usually include it.
Potassium in a Typical Serving of Cod
How you prepare cod changes its potassium content noticeably. Fresh Atlantic cod that has been baked or broiled provides about 207 mg of potassium in a 3-ounce portion, based on figures from the American Kidney Fund. Canned cod packed in liquid comes in significantly higher, at around 449 mg for the same weight, because the canning liquid concentrates minerals. If you are watching your potassium intake, the preparation method matters more than most people realize.
For context, the daily adequate intake for potassium is 2,600 mg for women and 3,400 mg for men. A serving of fresh cod supplies roughly 6 to 8 percent of that target, making it a contributor but not a major source.
How Cod Compares to Other Fish
Among popular white fish, cod sits in the middle of the potassium range. Halibut and yellowfin tuna tend to be higher, often delivering 400 to 500 mg per 3-ounce cooked serving. Salmon falls in a similar range. Tilapia and shrimp are generally lower, closer to 150 to 200 mg per serving. If you are choosing fish specifically for its potassium profile, cod is one of the more moderate options available at most grocery stores.
Cod on a Kidney-Friendly Diet
People managing kidney disease often need to limit potassium, and fish can be a gray area. The American Kidney Fund lists Atlantic cod at 207 mg per 3-ounce serving, placing it right at the border between low and medium potassium. Many renal dietitians consider foods under 200 mg per serving “low potassium” and those between 200 and 300 mg “medium.” Cod falls into that medium category, but just barely.
Cod also has a favorable sodium profile. A 3-ounce serving of cooked cod contains about 65 mg of sodium, which is just 3 percent of the daily value. That combination of moderate potassium and low sodium makes cod one of the more kidney-friendly protein choices compared to red meat or processed foods.
Cooking Methods That Lower Potassium
Boiling or soaking fish in water before eating it pulls potassium out of the flesh and into the cooking liquid. Research published in the Journal of Renal Nutrition found that soaking fish in hot water (a 5-to-1 water-to-food ratio for 5 to 10 minutes) reduced potassium content by 30 to 39 percent. Applied to a 3-ounce serving of cod at 207 mg, that technique could bring the potassium down to roughly 125 to 145 mg, well within the low-potassium range.
Baking, grilling, and pan-searing do not have this leaching effect because there is no water to draw the minerals out. If potassium reduction is your goal, poaching cod or boiling it briefly before finishing with another cooking method gives you the best of both worlds: lower potassium and better flavor than plain boiled fish. Just discard the cooking water rather than using it for sauces or soups, since that is where the extracted potassium ends up.
Canned vs. Fresh Cod
The gap between canned and fresh cod is worth highlighting for anyone monitoring their intake. Canned Atlantic cod with its packing liquid contains about 449 mg of potassium per 3-ounce serving, more than double the amount in a fresh fillet. Draining and rinsing canned cod can reduce this somewhat, but it will still be higher than a fresh piece that has been baked or broiled. If potassium is a concern for you, fresh or frozen cod is the better choice over canned.