The following come from beef, chicken, fish, eggs, and you don’t get from plants: Vitamin B12, EPA and DHA omega-3, Vitamin D3, Creatine, Taurine, Carnosine, retinol.

Plant provide, but less efficiently: iron, zinc, choline, calcium (some tofu provides, but depends on coagulant used), iodine.

On the flip side, plants provide fiber and numerous phytochemicals that meat, fish, and eggs lack.

Calcium, iron, zinc, et al. To avoid deficiencies on a plant-based diet, you have to carefully manage your diet around them.

Anecdotally, my sister in law has been vegetarian for over a decade and just recently been diagnosed with anemia.