Diet doesn't work limitary. 
Dietary needs or health can be understand out of a evolutionary perspective. It's praxeology. 
We emerged at the south east African rift and migrated along the sea to Europe. Cold periods in evolution forced us to get our food out of the sea We ate lots of fish during our evolution. 
That's why the biggest nutrition deficiencies are omega 3 and iodine nowadays!
Just do the things human used to do in evolution. Stay outside in the sun, grounded and eat the things that have been around regionally for the last 100000 years.
Eat seafood 
#DHA is power