Yes, fish contains iron, though the amount varies significantly by species. A 3-ounce serving of cooked skipjack tuna provides about 1.36 mg of iron, while the same serving of cod delivers just 0.42 mg. That range matters if you’re counting on fish as an iron source, so the type of fish you choose makes a real difference.
Iron Content by Fish Species
Darker-fleshed fish consistently outperform white fish when it comes to iron. Here’s how common species compare per 3-ounce cooked serving, based on USDA nutrient data:
- Skipjack tuna (fresh, cooked): 1.36 mg
- Pink salmon (canned with bone): 0.71 mg
- Chum salmon (cooked): 0.60 mg
- Wild coho salmon (cooked): 0.60 mg
- White tuna (canned in oil): 0.55 mg
- Atlantic cod (canned): 0.42 mg
Mackerel is worth noting separately. Canned jack mackerel contains 0.58 mg per single ounce, which means a full 3-ounce portion would land it near the top of this list.
Why Dark Fish Has More Iron
The color of a fish fillet is a surprisingly reliable clue to its iron content. That reddish-brown color in tuna and mackerel comes from myoglobin, an oxygen-carrying protein packed into muscle tissue. Fish that swim continuously over long distances need more oxygen flowing to their muscles, so they develop more myoglobin-rich “red” muscle. White-fleshed fish like cod and tilapia are less active swimmers with less myoglobin, and correspondingly less iron.
This is the same reason dark-meat chicken has more iron than white meat. The biology is identical: muscles that work harder store more oxygen-binding proteins, and those proteins contain iron at their core.
Fish vs. Beef and Shellfish
If you’re choosing fish specifically for iron, it helps to know where it stands against other protein sources. A 3-ounce serving of beef contains about 3.0 mg of iron, roughly double the best finfish option (skipjack tuna) and more than seven times what you’d get from cod. For someone trying to boost iron intake, beef is the more efficient choice per serving.
Shellfish, on the other hand, can blow both finfish and beef out of the water. Whole baby clams pack up to 17.2 mg of iron in a standard reference portion (about 2 ounces), making them one of the most iron-dense foods available. Even processed clam products vary widely, though: minced clams drop to as little as 0.57 mg per portion. If you see clams touted as an iron superfood, the preparation matters enormously.
One important distinction: the type of iron in these foods differs. Beef gets most of its iron from heme iron (2.3 mg per serving), which your body absorbs efficiently. Clams, despite their high total iron numbers, contain very little heme iron (less than 0.4 mg per serving). Fish is classified as a heme iron source, but its total iron content is modest enough that you’d need to eat it alongside other iron-rich foods to meet daily targets.
How Much Iron You Actually Need
The recommended daily intake for iron depends heavily on your age and sex. Adult men and women over 51 need 8 mg per day. Women between 19 and 50 need 18 mg, more than double the male requirement, largely because of menstrual blood loss. During pregnancy, that number jumps to 27 mg.
To put fish in context: a 3-ounce serving of fresh tuna covers about 17% of an adult man’s daily iron needs but only 7.5% of a premenopausal woman’s. Fish contributes to your daily total, but it’s not going to carry the load on its own for anyone with higher iron requirements.
Getting More Iron From Your Fish Meal
The iron in fish is heme iron, which your body absorbs more readily than the non-heme iron found in plant foods like spinach and beans. You can further boost absorption by pairing fish with vitamin C-rich foods at the same meal. A squeeze of lemon on salmon, a side of bell peppers with tuna, or tomato-based sauces with cod all help your body pull more iron from the food.
This pairing strategy works in both directions. Heme iron from fish also enhances absorption of non-heme iron from any plant foods you eat alongside it. So a meal combining fish with lentils and roasted vegetables gives you a triple advantage: heme iron from the fish, non-heme iron from the plants, and better absorption of the plant iron thanks to both the fish and any vitamin C on the plate.
If maximizing iron from fish is a priority, choose dark-fleshed species over white fish, and build meals that include colorful vegetables or citrus. The difference between a plain cod fillet and a tuna steak with roasted tomatoes isn’t just flavor. It’s a meaningful gap in how much iron your body actually takes in.