The essential amino acid histidine is manufactured in sufficient quantities in adults, but children may at some time have a shortage of this important nutrient.
It is one of the basic (reference to pH factor) amino acids due to its aromatic nitrogen-heterocyclic imidazole side chain. This amino acid is metabolized into the neurotransmitter histamine and the set of genes that produce the enzymes responsible for histidine synthesis.
Histidine is also a precursor of histamine, a compound released by immune system cells during an allergic reaction.
It is needed for growth and for the repair of tissue, as well as the maintenance of the myelin sheaths that act as protector for nerve cells.
It is further required for the manufacture of both red and white blood cells, and helps to protect the body from damage caused by radiation and in removing heavy metals from the body.
In the stomach, histidine is also helpful in producing gastric juices, and people with a shortage of gastric juices or suffering from indigestion, may also benefit from this nutrient.
The dosage listed is the Recommended Daily Allowance (RDA), but be aware that this dosage is the minimum that you require per day, to ward off serious deficiency of this particular nutrient. In the therapeutic use of this nutrient, the dosage is usually increased considerably, but the toxicity level must be kept in mind.
Some people take 1,000 mg of histidine two to three times per day in capsule or tablet form but it is best to work out the dosage requirements as 8-10 mg per day per kilogram of body weight.
Toxicity and symptoms of high intake
There are no reported side effects with histidine.
Too high levels of histidine may lead to stress and mental disorders such as anxiety and people with schizophrenia have been found to have high levels of histidine.
People suffering from schizophrenia or bipolar (manic) depression should not take a histidine supplement without the approval of their medical professional.
Best used with
When more may be required
Although not conclusively proven – it is thought that histidine may be beneficial to people suffering from arthritis and nerve deafness.
Other interesting points
Histidine is also used for sexual arousal, functioning and enjoyment.
Histidinemia is an inborn error of the metabolism of histidine due to a deficiency of the enzyme histidase, where high levels of histidine is found in the blood and urine, and may manifest in speech disorders and mental retardation.
Histidine food sources
Dairy, meat, poultry, and fish are good sources of histidine as well as rice, wheat and rye.
Histidine is found in the following Zest for Life products