Amino acid supplementation sounds like a strategy that a body builder might use to get jacked, but in reality, amino acids are used for more than just building muscle. Amino acids form proteins, and proteins form many different important molecules that are used in your body . Sure, proteins build muscle but amino acids also form enzymes, neurotransmitters, can be used as energy and are essential for many biological processes.
It is not surprising that an amino acid imbalance could have devastating effects to a person’s health. When we think of an amino acid deficiency we might think about a protein deficient diet, but what if your body did not have the genetic code to create these important amino acids? 
At AANP I attended a talk on the importance of amino acid testing as a treatment for autism. It is fascinating how a simple amino acid can have so many devastating effects on the body, Dr. Jared Skowron spoke about the current methods he uses at his clinic to test for amino acid imbalances, and the different recommendations he makes that have changed people lives. 
During his talk I learned that eating a whole foods diet that includes easily absorbable protein could be enough to maintain a good balance of amino acids. There might be many obstacles to this absorption, for example, poor digestion, low quality protein, intestinal permeability  or even genetic mutations that prevent you from using these building blocks.
What I took from that talk is that nutrition is very complicated, and you could have a perfect diet but you could still have obstacles that are not addressed by your diet. Yes, you should correct your diet and try to eat the healthiest and most anti-inflammatory diet you can achieve, but what if your diet does not get you to an optimal state of health? That’s where practitioners become indispensable, a trained physician will be able to order labs, diagnose and suggest strategies to correct the underlying problem. Does that mean that we can supplement ourselves out of sickness? No, what it means is that in specific diseases, you might need some supplemental amino acids that you might not be able to get from a normal diet.
My biggest take was, that sometimes difficult diseases such as autism could be just a couple of amino acids away from a resolution. It makes me so excited to be in a profession that allows me to think outside the box, and eventually it will let me help those patients that many think are beyond help.
1.- Erdmann, R. & Jones , M., (1987) The Amino Revolution, First Fireside Edition, p2.
4.- Rapin JR, Wiernsperger N. Possible links between intestinal permeability and food processing: A potential therapeutic niche for glutamine. Clinics (Sao Paulo). 2010;65(6):635-43.