Origin: Mediterranean. Red tuna is also known as the "steak of the sea," because its firm, dark red flesh and stronger flavor resemble meat. Other similar species within this family include mackerel. It is rich in proteins, fatty acids, omega-3, selenium, phosphorus, niacin, vitamin D, B12, and B6. Tuna is one of the most consumed blue fish in our country. Its flesh contains 12% fat, making it a fatty fish, and the fat is rich in omega-3 fatty acids. Furthermore, tuna is the fish most abundant in high-quality proteins in the diet, with 23g per 100g, even higher than meats. Compared to most fish, tuna stands out for its nutritional composition rich in various vitamins and minerals. Among the B vitamins, tuna is a source of B6, niacin, D, and B12. Its content of B12 surpasses that of meats, eggs, and cheeses, which are natural sources of this vitamin. Tuna is also a source of vitamin D. A serving of tuna provides 250% of the recommended intake of this vitamin for the studied population group. As for minerals, tuna is a source of phosphorus and has a high content of selenium.