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Selenium

Se2-

Overview​

Selenium is a chemical element; it has symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium (from σελήνη "moon") was discovered in 1817 by Jons Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth) Wikipedia: Selenium. Selenium is an essential trace mineral that functions as a critical cofactor for glutathione peroxidase (GPx) and other antioxidant enzymes. These selenium-dependent enzymes protect cell membranes and mitochondria from oxidative damage by neutralizing harmful reactive oxygen species. Selenium works within the broader antioxidant network, supporting redox balance and protecting against oxidative stress that can impair brain function. Adequate selenium intake is important for maintaining antioxidant defenses, particularly in tissues with high metabolic activity like the brain.

Dietary absorption and meal context​

  • Food distribution: Selenium content in foods varies substantially by soil and feed conditions, so food composition can differ across regions.
  • Food-first strategy: Seafood, eggs, meats, and moderate portions of selenium-rich nuts can support adequacy.
  • Practical caution: Avoid frequent high-dose intake because selenium has a narrower safety margin than many other minerals.

Recipes​

6 recipes containing this substance

Chocolate Quinoa Crisp Clusters

A delicious cereal-to-snack hybrid with satisfying crunch, steady energy, and a low glycemic profile. Perfect for breakfast or anytime snacking.

Salmon Bowl-pistachio-cacao-nibs

A Mediterranean-style bowl combining salmon, avocado, pistachios, cacao nibs, and early harvest olive oil — rich in omega-3 fats, polyphenols, and fibre.

Turkey Wing Stew

A collagen-rich, glycine-heavy slow-cooked stew made from affordable turkey wings — rich in protein, tryptophan, and B vitamins.

Foods​

19 foods containing this substance

Beef

High creatine, CoQ10, and bioavailable heme iron

Cheddar Cheese

Hard cow’s-milk cheese rich in protein, calcium, and vitamin B12

Chicken

Niacin, zinc, and tryptophan

Cockles

Bivalve shellfish providing B12, iron, zinc, selenium, and marine taurine

Crab

Seafood providing zinc and complete protein

Duck Fat

Oleic acid, selenium, and palmitoleic acid for cooking

Eggs

Complete protein with choline, B vitamins, and phospholipids

Mushrooms

UV-exposed mushrooms provide vitamin D; niacin source for NAD+ synthesis

Mussels

Nutrient-dense bivalve providing phospholipid-bound omega-3s; accepted by some vegans (ostroveganism)

Oats

Beta-glucans, B vitamins, and minerals for gut and neurotransmitter support

Oysters

Highest zinc content among common foods; unique source of phospholipid-bound omega-3s; accepted by some vegans (ostroveganism)

Salmon

Oily fish rich in EPA/DHA, protein, and B vitamins

Sardines

Small oily fish rich in EPA/DHA, CoQ10, and calcium

Shrimp

Seafood providing protein and minerals

Tofu

Soy-based protein source with isoflavones and choline

Tuna

Fish providing omega-3, niacin, selenium, and complete protein

Turkey

High tryptophan and niacin for serotonin synthesis and NAD+ production

Biological Mechanisms and Implications​

Biological TargetTherapeutic AreasMechanism of Action
Mitochondrial Function & BioenergeticsProtects mitochondria from oxidative damage through antioxidant enzyme activity
Oxidative StressSupports glutathione peroxidase (GPx) and other antioxidant systems, protecting membranes and mitochondria from oxidative damage

References​

  • Selenium supports glutathione peroxidase and other antioxidant systems, protecting membranes and mitochondria from oxidative damage
  • Included among trace minerals essential for antioxidant networks