How much selenium do I need per day?

Most adults need 55 mcg per day. Pregnancy is 60 mcg per day and breastfeeding is 70 mcg per day.

What foods are highest in selenium?

Seafood, meat, eggs, and Brazil nuts are common high-selenium choices. The exact amount in foods can vary by sourcing and soil.

Are Brazil nuts a good way to get selenium?

Yes, but they are easy to overdo. One nut can already cover or exceed a full day for many people, and the selenium content varies a lot by brand and origin.

Can I get too much selenium?

Yes. The tolerable upper intake level for adults is 400 mcg per day. The main risk is supplements or frequent Brazil nuts, not normal mixed diets.

Should I take a selenium supplement?

Most people do not need one. If you are considering selenium for thyroid or immunity reasons, talk to a clinician first instead of guessing.

What are common signs people associate with too much selenium?

People often mention nausea, garlic-like breath, brittle nails, hair loss, or skin issues. If you suspect excess, stop supplements and get medical guidance.

Does selenium support thyroid function?

Selenium is involved in enzymes that relate to thyroid hormone metabolism. That does not mean high-dose selenium is a good idea. Food-level intake is usually the smart baseline.

What is the easiest selenium strategy this week?

Add a selenium-rich protein a couple times per week, like seafood or eggs, and avoid adding selenium supplements on top unless you have clear guidance.

Selenium

Selenium is a trace mineral your body uses for antioxidant defense and thyroid hormone metabolism. Most adults need 55 mcg per day, pregnancy needs are 60 mcg, and breastfeeding needs are 70 mcg. Selenium is one of those nutrients where food usually covers you, but supplements and Brazil nuts can push you over the safe upper limit if you are not careful.

Supports antioxidant systems that protect cells from oxidative damage
Plays a role in thyroid hormone metabolism
Supports normal immune function
Needs are small, but excess from supplements can be a real risk
Food selenium varies based on soil and sourcing

Try BeyondCal for free

How BeyondCal helps you track selenium

Track selenium automatically from logged foods and meals
See your rolling average over time after you log food
See how far you are from your daily target
Find which meals contribute most to your selenium intake

Exact values and your gap are shown in the app after you log food.

See this in the app

What this helps with

What supports healthy selenium status

Adequate protein intake supports many selenium-dependent enzymes and makes selenium intake more predictable
Vitamin E and selenium are often discussed together in antioxidant defense, so tracking both can add context
A whole-food diet pattern tends to deliver selenium without pushing you into excessive supplement territory

Playbook

Raise it fast

Fastest ways to increase selenium with food

Add seafood a couple times per week, like salmon, tuna, sardines, or shrimp. Many servings land roughly in the 30 to 90 mcg range
Use eggs more often: a typical large egg is roughly 15 mcg
Add turkey or chicken as a protein anchor: common servings are often in the 20 to 40 mcg range
Use dairy staples if they fit your diet, like yogurt or milk, which can contribute small but consistent amounts
Use Brazil nuts carefully. One nut can contain roughly 60 to 100 mcg and can overshoot your daily needs fast

Food swaps

Simple swaps that add selenium without changing everything

One plant-only dinner each week -> seafood dinner sometimes
Snack bars -> a hard-boiled egg plus fruit
Low-protein salad -> add turkey, chicken, or shrimp
Random protein -> rotate in fish once or twice per week
Brazil nuts daily -> Brazil nuts occasionally, not as a daily habit

Timing tips

Practical tips to avoid the common selenium mistakes

Do not stack selenium supplements on top of selenium-rich foods unless a clinician tells you to
If you eat Brazil nuts, treat them like a strong tool, not a casual snack
Track the weekly pattern. Selenium is easy to overshoot if you repeat the same selenium-heavy item daily
If thyroid health is a concern, focus on overall diet quality and avoid self-prescribing high-dose supplements

Absorption blockers and interactions

What can block or reduce absorption

What can get in the way, or push selenium too high

High-dose selenium supplements can push you over safe limits quickly
Brazil nuts vary a lot by source and can be extremely selenium-dense, so they can overshoot fast
If you take multivitamins plus other targeted supplements, selenium can get duplicated without you noticing
If you have thyroid disease, kidney disease, or are pregnant, talk to a clinician before using selenium supplements

If you eat like this, watch out

You should pay extra attention if

You avoid seafood, eggs, and meat, and you rarely use selenium-rich staples
Your diet is very repetitive and lacks protein variety
You take a multivitamin plus extra "immune" or "thyroid" supplements
You eat Brazil nuts frequently as a daily habit
You have thyroid disease or kidney disease. In this case, get clinician guidance before supplementing

Track together

Selenium is easiest to interpret with context. Tracking it with protein helps because selenium usually rides with protein-rich foods. Tracking it with vitamin E and vitamin C can help you see the antioxidant-related pattern of your diet. Tracking it with zinc and copper helps you avoid the common trap of stacking multiple minerals through supplements.

Related nutrients

FAQ

Sources

Disclaimer: Educational only, not medical advice. Talk to a qualified clinician for personal guidance.

Read full disclaimer

The information provided is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Individual nutrient needs vary by age, sex, health status, medications, and other factors. Selenium is a nutrient where excess can be harmful, especially from supplements and frequent Brazil nut intake. If you have thyroid disease, kidney disease, are pregnant, take medications, or are considering supplements, consult a qualified healthcare provider. BeyondCal helps you track intake from food logs, but it does not replace professional medical advice.