Histidine — an essential amino acid necessary for protein synthesis, hemoglobin formation, and histamine production.
It plays an important role in the immune system, regulates stomach acidity, participates in nerve impulse transmission, and protects cells from oxidative stress.
The body cannot produce histidine on its own, so its intake from food is extremely important, especially during periods of growth, recovery, and physical exertion.
Health Benefits
- contributes to hemoglobin synthesis and supports blood health;
- ensures the production of histamine — a neurotransmitter and participant in the immune response;
- regulates acidity in the stomach by stimulating hydrochloric acid secretion;
- participates in tissue healing and regeneration;
- supports antioxidant protection of cells.
Daily Requirement and Sources
The recommended dose of histidine for adults is 10–14 mg per kg of body weight (approximately 600–1000 mg per day).
For children and pregnant women — up to 15 mg/kg.
Sources of histidine:
- meat: beef, pork, turkey;
- fish and seafood;
- eggs and dairy products;
- legumes: lentils, chickpeas, beans;
- nuts and seeds: sesame, pumpkin seeds.
Possible forms and their learnability
Nutrient forms are listed from best to worst:
L-histidine. The main and bioavailable form participates in the synthesis of histamine, hemoglobin, and enzymes, supports immunity, the gastrointestinal tract, and tissue healing. It is well absorbed and used in nutrition science for anemia, allergies, and chronic inflammation.
D-histidine. Does not participate in human metabolism, biologically inactive. Not used in supplements and nutrition.
Symptoms and Consequences of Deficiency
- anemia, fatigue, weakness due to impaired hemoglobin synthesis;
- decreased immune protection, increased susceptibility to infections;
- digestive disorders due to insufficient acidity of gastric juice;
- worsening of memory, attention, increased anxiety;
- slowed tissue recovery and wound healing.
Potential Risks of Excess and Their Manifestations
- increased histamine level (histaminosis) — itching, rash, redness, swelling, nasal congestion;
- increased acid secretion in the stomach, risk of gastritis or ulcers;
- imbalance of other amino acids (e.g., decreased levels of tryptophan and tyrosine);
- headaches, irritability, digestive problems;
- allergic reactions with excessive intake from food or supplements.
Doses above 5 g of histidine per day are considered potentially dangerous.