Until the age of seventeen, I was a meat and potatoes guy, sure I ate some fruits, but no veggies other than tomato sauce would pass these lips. In my first semester at community college I took a nutrition class; this would prove to be a big eye opener for me.
During this class I learned about having a balanced diet, and as a result I started eating vegetables, cut back on meat, increased fiber, and starting taking a multivitamin/mineral supplement daily. As a grew more conscious of the world around me I ultimately gave up all animal products other than milk and eggs.
Fast forward twenty five years…I am now very close to being a vegan, one cup of milk in my daily latte is about all I eat of animal products. I still take a vitamin/mineral supplement daily, I eat a very balanced diet, not much junk in my daily intake, lots of raw foods, don’t eat out much, don’t consume alcohol or drugs, etc…
I meet people, some whom were once vegetarian/vegan, who tell me that they “must have meat or they become unhealthy”. Is this true? Does your body “know” where a protein source was derived?
No. Your body doesn’t know if the protein you ate came from a cow or a soy bean, all it knows is what amino acids are contained in that protein. Note that you do need “complete proteins” which need to be eaten in certain combinations if you don’t eat meat or eggs (meat and eggs are generally considered complete proteins). So what goes for proteins, also goes for all nutritional components, fats, carbs, vitamins, minerals, fiber, your body only knows them for what they are, not for where they came from.
So, a balanced diet must include a certain ratio of these components, but how you get them is your choice, through balanced eating or in combination with supplements. There is no advantage to having extra anything; a high dose of vitamin C every day has no intrinsic benefit other than making your urine rich in vitamin C. In fact some vitamins and minerals in excess can accumulate in bad ways, though most are simply excreted in the urine. Extra protein, fat, and carbs are processed and stored by the body; we knows these by other names: love handles, flab, double chin, wings, etc…none of which are desireable last time I checked 
If you are concerned about having a nutritional deficiency, the best way to check is to have complete labs done by your medical provider, but the thing that you can do as an individual is to record what you eat for one month, then break it down and compare your results with what is the suggested by FDA or other organization, for your body type, age, activity level, etc…
Most Westerners eat too much protein, too many simple carbohydrates, not enough fiber, and too much saturated and trans fats. We also don’t drink enough water…
I strongly suggest that every college student take a nutritional class, it could literally save you life 
And if you met me, you would not believe I am a vegetarian; but you might mistake me for a cop 
