Liver is a food I personally stay away from, no matter how organic it is.
Sure it might be the first thing that natural carnivores eat when they catch another animal in the wild, and yes it's full of valuable vitamins, but for humans in the 21st century, it's not an optimal food in my opinion.
I don't know if you are aware of this but analysis have been carried out testing animal fat for toxins. All animal fat has some toxins to a certain extent today, it's impossible to avoid. Dioxin is found in something like 9 out of 10 organic egg brands (just Google "organic eggs dioxin" and "animal fat dioxin"). The amount in eggs, though, might be negligible. And I'm only using dioxin as an example for accumulation, dioxin might not be the worst toxin in food.
But then there is the liver. The organ which handles all toxins, filters and stores. Conversion from conventional farming to organic takes 2 years. It means that if you buy organic beef, that beef might well have been fed antibiotics, GMO food, hormones, injections, vaccinations and grain 3 years ago. That might not be important, though, since cells regenerate and toxins from conventional farming would not be in the animal after 2 years - especially in the liver, which is one of the fastest regenerating organs (I think the human liver renews itself so fast that you have a brand new liver every few weeks or less). With that said, the liver still contains an enormous amount of compounds/substances, by-products, waste-products, toxins, much more than any other organ or muscle meat I believe. And even organic farming is not 100% "bulletproof", if you look at the rules for organic farming you'll see that most countries require 95% or less of the food fed to animals to be organic and the cows don't have to be 100% grassfed. And it's far from required that the cows have access to outside pastures year round.
There is no magical nutrient found in liver which is not found in the other organs of animals. Liver also contains glycogen, making it a no-no for zero carbers.
I've heard of too many people who had bad experiences with raw liver so I'm not consuming it myself. I really see no reason.
If you really like liver and want to consume it, do it rarely in my opinion.