where you get your eggs is HUGE.
a poor quality egg has a fraction of the nutrition as a real egg
Dylan hit the nail on the head. you want to look for that certified humane sticker. organic, cage free, etc. don't mean shit... all eggs are technically organic lol. you need that actual sticker. a lot of supermarkets you might have only 1 eggs that have that out of 12 brands while a whole foods would have 90% of their eggs with it.
what i also look for is an orange yolk, this tells me that the chickens were eating bugs and seeds outside.