Yes you can.
Position of the Academy of Nutrition and Dietetics
It is the position of the Academy of Nutrition and Dietetics that
appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases. These diets are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes. Plant-based diets are more environmentally sustainable than diets rich in animal products because they use fewer natural resources and are associated with much less environmental damage.
Vegetarians and vegans are at reduced risk of certain health conditions, including ischemic heart disease, type 2 diabetes, hypertension, certain types of cancer, and obesity.
https://jandonline.org/article/S2212-2672(16)31192-3/fulltext
The Mayo Clinic
A well-planned vegetarian diet (see context)
can meet the needs of people of all ages, including children, teenagers, and pregnant or breast-feeding women. The key is to be aware of your nutritional needs so that you plan a diet that meets them.
Harvard Medical School
Traditionally, research into vegetarianism focused mainly on potential nutritional deficiencies, but in recent years, the pendulum has swung the other way, and
studies are confirming the health benefits of meat-free eating. Nowadays, plant-based eating is recognized as not only nutritionally sufficient but also as a way to reduce the risk for many chronic illnesses.
Dietitians of Canada
A healthy vegan diet can meet all your nutrient needs at any stage of life including when you are pregnant, breastfeeding or for older adults.
British Dietetic Association
Well planned vegetarian diets (see context) can be nutritious and healthy. They are associated with lower risks of heart disease, high blood pressure, Type 2 diabetes, obesity, certain cancers and lower cholesterol levels. This could be because such diets are lower in saturated fat, contain fewer calories and more fiber and phytonutrients/phytochemicals (these can have protective properties) than non-vegetarian diets. (...)
Well-planned vegetarian diets are appropriate for all stages of life and have many benefits.
The British National Health Service
With good planning and an understanding of what makes up a healthy, balanced vegan diet,
you can get all the nutrients your body needs.
The Dietitians Association of Australia
Vegan diets differ to other vegetarian diets in that no animal products are consumed or used. Despite these restrictions, with good planning it is still possible to obtain all the nutrients required for good health on a vegan diet.
I can post more, if you want. Plus, there are lots of people who have been either vegan or vegetarian their whole life, and are super healthy and smash all the lies that we've been sold, such as the idea that meat and dairy is necessary.
I would take such assessments with goodly measures of salt. Why? Because we live in an age where
everything has been politically weaponized. This includes the opinions, assessments, interpretations, and other determinations of a great many institutions. Herein we find yet another deep danger directly following from the political correctness bestowed upon us by "progressives" and the resultant fall-away from proper ethics that has grabbed humanity by the throat, shaking us with non-trivial violence for the sake of getting that which one desires. As I've written so many times before, humanity is deep in the kimchee.
I would also note that one ought not have to
plan one's diet beyond the now age-old adage of "proper balance".
I spent two years as a vegetarian in college. I rode approximately 700 miles (bicycle) every week, was strong as bleeding hell, and still had some problems as a result of having forsaken animal proteins, the most prominently obvious being that of endurance. After about 80-90 miles I would invariably begin to flag. One of the trainers with the Davis Bike Club suggested I become a track racer because as he put it, "you have the strongest legs I've seen in anyone, but you don't have the wind to go distance". I attribute that largely to the diet because the moment I went back to meat, my endurance increased markedly. I do not regard that as a coincidence.
That all aside, having to plan one's meals to the degree I witnessed in my vegetarian acquaintances is not natural in any way, shape, or form. Without current technology, which is to say if we were reduced to stone-age tech by whatever catastrophic means, vegetarians would likely be faced with the choice of getting serious about eating, or dying off. That goes double for vegans, who I do not think are dietetically rational.
While I'm at it, allow me to clarify a point I made previously regarding meat-eating being essential to our survival.
While we may as humans get by without eating meat, it is becoming clear that not consuming animal protein causes fundamental changes in both cognition and temperament. Disregarding the cognitive angle, if veganism leads to a form of soy-boy syndrome, and this apparently has been suggested by some research, then unless we eliminate all consumption of non-human animalia, those who continue to eat meat position themselves in both terms of physical strength and aggressiveness to dominate the rest. Therefore, even if America became 95% soyfags, our desire not to be depredated by whomever... China, Mexico... even Canada <snurk> would dictate that those who guard the rest would have to retain the meat-eater's edge by... well... eating meat. That, of course, leaves the 95% at the mercy and good behavior of the 5% who have retained their proper capacities as predators.
Therefore, no matter how you slice this pie, walking away from animal protein leaves one at a notable disadvantage.
Besides, critters taste good. Don't get me wrong, I don't like killing anything - not even for the sake of eating. I am, in fact, having a VERY bad week because my does threw eight kids and five of them died, so my own head is in knots over this... foolishly I admit, but that's how I roll... as a fool for babies of any sort. So it is not like I cannot wait to git on my Carharts and git-a-gunnin' fer Bambi the moment season opens. It is all very distasteful to me, but I accept our lot on this world as meat eaters and what that all implies. I do not, however, have to like it, and I don't. As I wrote, I am a fool.