Iron transports oxygen around your bloodstream, giving your cells plenty of oxygen to function. While some varieties of whole fish will indeed provide a small amount of iron, no matter which type of fish oil you consume -- cod liver, sardine and salmon, among others -- you won’t be adding any iron to your diet. During processing, the fats are separated from the fish, leaving behind certain nutrients. You’ll get a hearty dose of heart-healthy monounsaturated and polyunsaturated fats from fish oil and sometimes vitamins A and D, but not any minerals.
If you’re trying to up your iron intake and you enjoy fish, you’re better off eating the entire fillet, rather than just a spoonful of oil. Eating a 3-ounce serving of broiled sockeye salmon provides you with 0.4 milligrams of iron. Cooked yellowfin tuna has double that amount with about 0.8 milligrams in a 3-ounce cut. Three ounces of baked halibut provides 0.2 milligrams, while the same amount of light tuna canned in water has upwards of 1.3 milligrams of iron.