Enough With Omega-3s. What Else Do Fish Offer?

When people talk about the benefits of eating fish, omega-3 fatty acids usually steal the spotlight—and for good reason. They’re important, widely studied, and often the first thing that comes to mind.

But fish offer far more than just omega-3s. From essential vitamins to powerful minerals and amino acids, many common fish provide a wide range of nutrients that support heart health, immunity, brain function, and overall well-being. Here’s a closer look at what fish bring to the table beyond omega-3s.

Salmon

Let’s momentarily set omega-3s aside—though salmon remains one of their richest sources. When combined with potassium, omega-3s in salmon help reduce artery inflammation, lower blood pressure and cholesterol, and decrease the risk of heart disease (with the added bonus of shinier hair).

Salmon is also one of the best natural sources of vitamin D. A 3.5-ounce serving of wild-caught salmon can deliver up to 700 IU, surpassing the USDA’s recommended daily intake of 600 IU. Just one serving supports immune health, strong bones, and healthy muscle function.

Halibut

Halibut contains some omega-3s (about 250–500 milligrams), though not as much as salmon—but it shines in other nutritional areas.

A 6-ounce serving provides an impressive 38 grams of protein, along with 91% of the recommended daily intake of vitamin B12, 135% of selenium, 71% of niacin, 40% of magnesium, and 37% of vitamin B6.

Cod

So influential in New England that Cape Cod was named after it, this mild, flaky white fish delivers serious nutrition with minimal fat.

A 3-ounce serving of cod contains roughly 19 grams of protein, just about 1 gram of fat, and only 85–90 calories. While cod offers modest omega-3 levels (under 250 milligrams), it’s rich in B vitamins that help your body extract energy and nutrients from food.

Sablefish

Often compared to Chilean sea bass for its texture, sablefish—also known as black cod or butterfish—becomes tender and flaky when cooked.

Unlike lean white fish, sablefish is rich and buttery, offering over 1,000 milligrams of omega-3s per serving, comparable to salmon. It also delivers generous amounts of vitamins D and B12, along with selenium.

Tuna

Tuna is one of the most substantial fish available, frequently sold as steaks thanks to its meaty texture and clean, mild flavor.

Part of the Thunnini tribe, which includes varieties like albacore, bluefin, yellowfin, Atlantic, and Pacific tuna, these fish share similar nutritional benefits. Bluefin tuna provides about 1.6 grams of omega-3s per serving. Tuna is also high in protein (about 19.8 grams per serving), low in calories, and rich in vitamin D (193 IU), vitamin B6, iron, potassium, and selenium.

Essential Nutrients Found in Fish

Vitamin A – Supports healthy teeth, skin, and eyes and is essential during pregnancy and breastfeeding.
Vitamin B3 (Niacin) – Aids cell production, nerve function, digestion, and energy metabolism.
Vitamin B12 – Helps prevent anemia and fatigue while supporting cognitive health.
Vitamin D – Critical for calcium absorption, bone strength, muscle function, brain health, and immunity.
Tryptophan – An essential amino acid that supports protein production, mood regulation, and sleep.
Iron – Necessary for oxygen transport, healing, and growth.
Zinc – Supports immune health, cell growth, and wound repair.
Potassium – Helps regulate blood pressure and counter high sodium intake.
Magnesium – Involved in over 600 cellular processes, including muscle contraction and DNA production.
Phosphorus – Essential for bone health, energy production, and nerve signaling.
Iodine – Supports thyroid function and cognitive health, especially during fetal development.
Selenium – Supports metabolism and thyroid function while acting as a powerful antioxidant.