Nutriberres are good.
But leafy greens and veggies, are really good for your bird
I hear a lot of posts that people say oh my bird won’t eat veggies. Not saying that’s you.
But parrots love veggies and leafy greens , once they understand they are food and start trying them. My burds will even choose to chomp on veggies over sunflower seeds! And my birds all started out as seed addicts who had never seen a veggie.,
I think having fresh food as part of the diet is so very important. We don’t know every component in food, and aren’t able to replicate it in full , at least not yet. The antioxidants , vitamins, micronutrients, enzyme, pre biotic, flavonoids, sbd more. That are found in fresh food.
So yes pellets and the like are great. But it’s still important to have fresh leafy greens ( they are packed with vitamin and nutrition ) veggies, some fruits like berries, legumes are a good protein source, or dine boiled egg here and there.. as part of the diet.
In my ornithology thread, I managed to find a few studies on parrot nutrition. The few studies found a strict pellet diet of 100% pellets only did not meet all the parrots nutrition needs. They found the addition of small amount of seeds and veggies was need fir optimum metabolic health. This study included blood work and other measures.