"I'm too lazy to find it but there's plenty of examples"
You are also too lazy to find out you are flat-out wrong. It's pathetic that people think being vegan is healthy. Its not.
The following is quoted from Nutrition.org, a list of nutrients vegans must supplement because plants alone cannot provide it:
*1) To avoid B-12 deficiency, vegans should regularly consume vitamin B-12–fortified foods, such as fortified soy and rice beverages, certain breakfast cereals and meat analogs, and B-12–fortified nutritional yeast, or take a daily vitamin B-12 supplement. Fermented soy products, leafy vegetables, and seaweed cannot be considered a reliable source of active vitamin B-12. No unfortified plant food contains any significant amount of active vitamin B-12.
2) To ensure adequate calcium in the diet, calcium-fortified plant foods should be regularly consumed in addition to consuming the traditional calcium sources for a vegan (green leafy vegetables, tofu, tahini). The calcium-fortified foods include ready-to-eat cereals, calcium-fortified soy and rice beverages, calcium-fortified orange and apple juices, and other beverages. The bioavailability of the calcium carbonate in the soy beverages and the calcium citrate malate in apple or orange juice is similar to that of the calcium in milk (78, 79). Tricalcium phosphate–fortified soy milk was shown to have a slightly lower calcium bioavailability than the calcium in cow milk (78).
3) To ensure an adequate vitamin D status, especially during the winter, vegans must regularly consume vitamin D–fortified foods such as soy milk, rice milk, orange juice, breakfast cereals, and margarines that are fortified with vitamin D. Where fortified foods are unavailable, a daily supplement of 5–10 μg vitamin D would be necessary. The supplement would be highly desirable for elderly vegans.
4) A vegan should regularly consume plant foods naturally rich in the n–3 fatty acid ALA, such as ground flaxseed, walnuts, canola oil, soy products, and hemp seed–based beverages. In addition, it is recommended that vegans consume foods that are fortified with the long-chain n–3 fatty acid DHA, such as some soy milks and cereal bars. Those with increased requirements of long-chain n–3 fatty acids, such as pregnant and lactating women, would benefit from using DHA-rich microalgae supplements.
5) Because of the high phytate content of a typical vegan diet, it is important that a vegan consume foods that are rich in zinc, such as whole grains, legumes, and soy products, to provide a sufficient zinc intake. Benefit could also be obtained by vegans consuming fortified ready-to-eat cereals and other zinc-fortified foods.*
Here is an interesting section from an article published at LiveScience.com:
Judging what is natural is a slippery slope. Humans around the world live to relatively similar ages on a multitude of different diets. Most of the reasonable diets that consist of grains, vegetables and meats will get you to at least age 70 if an accident or infectious disease doesn't kill you first. A traditional, animal-based diet eaten by natives of Siberia is just as natural as a traditional diet eaten by unnamed tribes in the Amazon.
That said, no known human culture has ever attempted to survive solely on raw plant foods. It is the raw-only diet that is unnatural, because it is impossible to survive on this diet without modern conveniences such as refrigerators, storage devices and easy access to packaged foods — such as the aforementioned shelled nuts.
In fact, a child raised on a raw, vegan diet without proper supplementation would likely develop severe neurological and growth problems due to a lack of vitamin B12 and other nutrients. Adults who have eaten animal products for more than 20 years, by contrast, have the benefit of relying on bodily stores of certain key nutrients.
In a natural setting, without electricity, anyone located outside of a narrow belt of land near the equators, which have year-round growth potential, would need to dedicate their entire day to growing, gathering, preserving and storing food. Even around the tropics, where vegetation is plentiful, humans have been cooking as long as humans have been human — at least 200,000 years and likely longer in our hominid form.
Most scientists are in agreement that a combination of, first, eating meat and then cooking food enabled the development of the human brain. Cooking in particular opened up a new world of calories and nutrients. The human brain, after all, requires a lot of energy. [Eating Meat Made Us Human, Study Suggests]
Our raw-vegan cousin, the gorilla, has three times the body size of humans, but one-third the brain cells; it grew muscular on plants, but not smarter. According to a study published in October 2012, the gorilla would have needed to eat raw plants for more than 12 hours a day to consume enough calories to evolve a humanlike brain.*
If you rely on human technologies to fortify your nutrient-deficient foods deemed to be "healthful", then you're doing it wrong!
Humans have to be omnivores to gain all necessary nutrients, as I have already said. Strictly vegan or strictly carnivorous diets are unhealthy