Serine is a non-essential amino acid, which means that it is required for the human body to properly function, but does not need to come from an outside source. Instead, it is typically produced within the body from metabolites, such as glycine. Serine, also known as Ser, is a proteinogenic amino acid. This means it is one of the 22 amino acids that are part of the standard human genetic code. The word proteinogenic is derived from the Latin for 'protein-building.'
In 1865, this amino acid was first isolated from protein contained in silk. Silk has a large concentration of it, and the amino acid was named using the Latin word sericum, which means silk. By 1902, the the chemical structure of serine had been determined.
The main uses of serine in the human body are to assist in the function of the central nervous system (CNS), as well as with general brain operation. It is present in the myelin sheaths that cover the nerves located in the brain. Without sufficient serine, these sheaths become thin or disappear altogether, leading to an inability for the nerves to transmit messages to other parts of the body.
This amino acid also aids in the production of antibodies and immunoglobulin, both of which are essential for a healthy immune system. In addition, the presence of serine is required to create tryptophan, which in turn is used to make serotonin. Serotonin is used by the brain to regulate mood, and depression and anxiety are linked to to a lack of either serotonin or tryptophan in the body.
In order for the human body to produce this amino acid, folic acid and both vitamins B3 and B6 must be present. These compounds naturally occur in meat, peanuts, and dairy products, but a diet high in processed foods can lead to a deficiency. Supplements are available in powder and tablet forms, but are most commonly found as part of a combination supplement, such as a nuttritional sports drink.
While rare, it is possible for the human body to have a natural deficiency of this amino acid. It is an inherited condition which prevents the bio-synthesis of L-serine from occurring. The condition presents in children with symptoms such as psycho-motor retardation and seizures. Symptoms of this disorder manifest as a neurological condition, and many children are not tested for L-serine deficiency. A simple spinal fluid test is typically enough to determine if this disorder is the underlying cause of the symptoms.