Meats are not all created equal

I try to eat a variety of protein sources, since I make a practice of getting the RDAs for the B vitamins from food. The nutritional profiles for beef, pork and chicken are actually pretty dissimilar:

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As you can see, beef is relatively high in B-12, zinc and iron. The iron requirement used in the graph is 18mg/day - the RDA for young women. Pork is high in thiamin and riboflavin. Chicken is high in niacin and B-6. All three meats have pretty similar protein and fat values.