Y'know, it really BUGS me that most health and nutrition websites - and books and magazine articles - include only vegetarian foods and dairy products in lists of "best sources of .." foods.
Sometimes they'll include fish.
Meats, poultry, fish and seafoods are good sources of important minerals and essential fatty acids, as well as the protein. Leaving them off those source lists tends to make readers think they have little nutrition to offer.
While fish are the best flesh sources of potassium, 100g (3˝ oz) cooked lean pork, beef or lamb will provide 350 - 400 mg, as much as a medium banana. Chicken and turkey a bit less, 250 - 300 mg.
Fish are also best sources of magnesium, but there again .. beef, pork, lamb, turkey and chicken all provide modest amounts .. 25 - 30 mg per 100g (3˝ oz) portion.
Canned fish with the bones (sardines, mackerel, salmon) are good sources of absorbable calcium .. 250 - 350 mg per 100g (3˝ oz) portion. While dairy products may contain large amounts of calcium, the high phosphorous content can inhibit absorption.
Fish, poultry - esp. turkey - and mollusks (oysters, mussels) are the hands-down best sources of selenium .. 135+ mcg per 100g (3˝ oz) portion. Beef, pork and lamb have modest amounts .. 40 - 50 mcg per 100g portion.
hth,
Doreen