Selenium

Selenium is a vital microelement-an antioxidantthat is part of more than 25 proteinsProteins are high-molecular organic substances consisting of alpha-amino acids linked in a chain by a peptide bond. In living organisms, the amino acid composition of proteins is determined by the genetic code. During synthesis, 20 standard amino acids are used in most cases. Many combinations of them determine the great diversity of properties of protein molecules. Proteins play a key role in the immune response and can perform transport, storage, catalytic, structural, and receptor functions. Proteins are an important part of the nutrition of animals and humans. The main sources of proteins are meat, poultry, fish, milk, nuts, legumes, and grains. (selenoproteins). Its main functions are:

1. Antioxidant protection:

• It is a part of glutathione peroxidase , an enzymeEnzymes are proteins that accelerate chemical reactions in the body. They ensure the occurrence of metabolic processes such as food digestion, energy release, cell formation, and many others. that neutralizes free radicals.

1. Thyroid Support:

• It is involved in the conversion of the hormone T4 (thyroxine) to T3 (triiodothyronine).

1. Immunity:

• Increases the activity of NK cells and T-lymphocytes.

1. Detoxification:

• Binds heavy metals (mercury, cadmium).

1. Reproductive health:

• It is necessary for sperm motility in men.

---

Symptoms of selenium deficiency

Deficiency occurs in regions with a low content of selenium in the soil (for example, some areas of China and Russia).

Main features:

• Weakness, muscle aches (due to oxidative stress).
• Violation of the thyroid gland (hypothyroidism, goiter).
• Reduced immunity (frequent infections).
• Infertility in men (oligospermia).
• Keshan’s disease (cardiomyopathy, found in endemic areas).

Risk groups:

• Vegans/vegetarians (exclude meat, fish).
• People with Crohn ‘s disease or celiac disease (malabsorption).
• Residents of regions with a selenium deficiency in the soil.

---

Symptoms of excess selenium (selenosis)

Overdose is possible with prolonged supplementation (>400 mcg / day).

Signs:

• Garlic breath odor (release of dimethyl selenide).
• Hair loss, brittle nails.
• Nausea, diarrhea.
• Neurological disorders (irritability, tremor).

Dangerous doses:

• > 900 mcg / day – risk of acute poisoning (vomiting, liver damage).

---

Selenium standards in analyses

The selenium level is determined in:

1. Blood (serum/plasma) – reflects the current intake.
2. In the urine – shows a long-term balance.
3. Hair/nails – accumulation over several months.

Reference values:

Critical levels:

• < 50 mcg/l (blood) – deficiency.
• > 200 mcg / l (blood) – excess.

---

When is the test scheduled?

1. Suspected selenium deficiency/excess.
2. Hypothyroidism of unknown origin.
3. Male infertility.
4. Living in endemic regions.

---

How to normalize selenium levels?

If there is a shortage:

• Products:
• Brazil nuts (1 nut = 50-100 mcg).
• Tuna, eggs, liver, garlic.
• Supplements:
• Selenomethionine (100-200 mcg / day).

If there is an excess:

• Cancellation of supplements.
• Increase the intake of sulfur-containing amino acids (methionine, cysteine) for detoxification.

---

Examples of deviations

• Selenium = 40 mcg / l (blood) + hypothyroidism → taking selenomethionine 100 mcg / day.
• Selenium = 250 mcg / l + hair loss → elimination of dietary supplements.

---

Conclusion

Selenium is a key antioxidant and thyroid regulator.
🔹 Rules:

• Blood: 70-150 mcg/l,
• Urine: 20-100 mcg/l
  . Дефицит Deficiency causes weakness, hypothyroidism, and immunodeficiency.
  🔹 Excess (>200 mcg/l – – toxic (damage to hair, nails, nervous system).
  🔹 Optimal dose: 50-200 mcg / day (from food or supplements).

Important: Brazil nuts are record holders for selenium, but 2-3 pieces a day is enough!