Iron, for one. Beans contain iron but so little of it that you’d have to consume 1.2kg to get your recommended daily intake. Similarly for a lot of other essential minerals.
GP just posted a table showing there is more iron in non-meat sources than in meat sources.
Iron is not an issue for any vegan I know. Spinach, beans, kale, etc are all super loaded with it.
See my other reply on the differences between heme and non-heme iron. You can’t just compare the mg figures listed on those tables. Many vegans and vegetarians test positive for iron deficiency [1].
FWIW the exact same thing is true of protein. Most people just think protein = protein, but it's not. Protein digestibility and amino acid balance vary radically, but tends to be very poor in non-meat sources. There's a table of scores for various foods here. [1] You can find the DIAAS score for most any food with a quick search.
So for example, fava beans are called high protein. 200g of fava beans has 220 calories, 15g protein, and a digestibility of 0.55. 200g of chicken breast has 220 calories, 46g of protein, and a digestibility of 1.08. You're getting about 6x as much protein in the chicken breast there. If somebody wants to maintain a relatively high protein diet, they're simply not going to be able to do that on a vegan/vegetarian diet unless they just start downing endless protein powder shakes.
Tofu e.g. has DIAAS of 0.97 and ~18g protein per 100g (checked the one in my fridge).
If you really need a lot of protein, you can just cook stuff with tvp, that usually has dry 50% protein, but I've seen also seen 75%. You basically hydrate it with water, add a bunch of spices cook, and eat it with whatever else you'd like.
I don't think there is a big difference for the average consumer, consider some processed stuff:
Protein/100g from the products on the rewe online store:
Vegan Nuggets: 9, 11, 3x13, 15, 17
Chicken Nuggets: 2x12, 13, 2x15, 16
Beef Burger: 17, 2x18
Vegan Burger: 10, 13, 2x14, 3x17
Salami: 3x21, 22, 23, 24, 25, 26
Vegan Salami: 2x8, 29, 32, 2x33
Reguarding DIAAS, soy and pea protein seem to be the most used and have 0.89 and 0.82 DIAAS respectively.
Vegetable sources of iron are called non-heme iron, in contrast to meat which is heme iron. Heme iron is readily absorbed and used by the body whereas non-heme iron is not [1]. Note that this applies to humans, not other animals. Cows are far better at absorbing these nutrients from plant sources than we are.
Iron is a nutrient, not a disease. The grandparent comment mentioned a disease that beef consumption cures that non-beef protein sources such as beans do not.
https://www.dietaryguidelines.gov/resources/2020-2025-dietar...