Several types of white fish are considered healthy and nutritious. Choose sustainably and responsibly sourced options: Cod: A lean white fish that is a good source of protein, vitamins B12 and B6, and omega-3 fatty acids. Halibut: A firm white fish that is rich in protein, potassium, and vitamin D. Tilapia: A mild-tasting fish that is low in calories and fat, but high in protein, vitamins B12 and D, and phosphorus and selenium. Mahi-Mahi: A mild-tasting white fish that is a good source of protein, potassium, and vitamin B12. Flounder: A lean white fish that is low in calories and fat, but high in protein and vitamins B12 and B6. Haddock: A lean white fish that is rich in protein and vitamins B6 and B12.