Introduction

Selenium is an essential trace mineral that functions as a powerful antioxidant. It plays a vital role in thyroid hormone metabolism, immune defense, DNA synthesis, and protection against oxidative stress.

What Is Selenium?

Selenium is a trace mineral incorporated into selenoproteins, which are critical for antioxidant and thyroid functions.

• Type: Essential trace mineral
• Main role: Antioxidant defense and thyroid health
• Storage: Distributed throughout body tissues

How Selenium Works in the Body

Selenium is required for the activity of glutathione peroxidase and other antioxidant enzymes.

• Protects cells from oxidative damage
• Supports conversion of thyroid hormones (T4 to T3)
• Enhances immune response
• Supports DNA synthesis and repair

Sources of Selenium

• Brazil nuts (very rich source)
• Fish and seafood
• Eggs
• Whole grains
• Sunflower seeds
• Dairy products

Selenium Deficiency

Selenium deficiency is uncommon but may occur in regions with selenium-poor soil or with malabsorption disorders.

Possible deficiency symptoms include:

• Weakened immunity
• Fatigue
• Muscle weakness
• Thyroid dysfunction
• Hair loss

Dosage & How to Take Selenium

• Adults: 55 mcg/day
• Pregnancy: 60 mcg/day
• Breastfeeding: 70 mcg/day
• Upper limit: 400 mcg/day

Selenium should be taken within recommended limits to avoid toxicity.

Forms of Selenium

• Selenomethionine
• Sodium selenite
• Sodium selenate
• Yeast-bound selenium

Benefits & Uses

• Provides antioxidant protection
• Supports thyroid hormone metabolism
• Boosts immune defense
• Supports heart health
• Promotes healthy hair and nails

Safety, Side Effects & Precautions

• Excess intake may cause selenium toxicity (selenosis)
• Symptoms include nausea, hair loss, and brittle nails
• Avoid exceeding upper intake limits
• Use caution with Brazil nuts due to high selenium content

Special Populations

• People with thyroid disorders: May benefit under guidance
• Pregnant women: Important for fetal development
• Elderly: Supports immune and thyroid health
• Individuals with poor soil diets: Higher deficiency risk

Frequently Asked Questions

What does selenium do in the body?

Selenium supports antioxidant defense, thyroid hormone metabolism, and immunity.

Can selenium be taken daily?

Yes. Daily intake within recommended limits is safe.

Is selenium good for thyroid health?

Yes. Selenium is essential for thyroid hormone activation.

Can too much selenium be harmful?

Yes. Excess selenium can cause toxicity symptoms.

Best natural source of selenium?

Brazil nuts are the richest natural source but should be consumed in moderation.