Timing Protocol

When to Take Selenium

What researchers say about when, how and with what to take selenium, and how strong the evidence is.

The verdict on Selenium overall

Leaning for

Selenium supplements are worth taking.

3 sources: 1 positive, 2 partly

3 sources: 1 positive, 2 partly

Based on what researchers say in publicly available videos, not medical advice. Always consult your healthcare provider before starting, stopping, or changing any supplement.

Short answer

Take it with food for better absorption. It can go with other thyroid nutrients (iodine, zinc, vitamin D).

Full Protocol

Timing
Take it with food for better absorption. It can go with other thyroid nutrients (iodine, zinc, vitamin D).
Dosage
55-200mcg daily. The RDA is 55mcg; functional medicine doctors often use 100-200mcg for thyroid and immune support.
Form
Brazil nuts (1-3 per day). Fish, eggs and organ meats as whole-food sources.
Notes
Selenium has a narrow safe range: the upper limit is 400mcg/day. Chronic excess causes selenosis (hair loss, gut upset, brittle nails, garlic breath). Brazil nut selenium varies a lot by origin, and South American nuts are usually highest. If you supplement, add up your food intake too.

What the evidence says about timing

One verdict, worked out from every counted mention. One dot is one source: a researcher or a study. Tap a dot to see its receipt.

positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.

Not enough evidence

Taking selenium with food improves its absorption.

2 sources: 2 negative. Fewer than 3 sources so far.

Researchers say

No researcher counted yet.

Studies show

2 negative

2 papers we read

Show the receipts from 2 sources
  1. Other primary study, J Trace Elem Electrolytes Health Dis, 1987, PMID 2856562 Study · negative

    Based on the rate of turnover of the radionuclides and the urinary losses of 75Se, the absorption of selenium, zinc and manganese from the supplement was estimated to be 89 +/- 5%, 38 +/- 7%, 9 +/- 3% (mean +/- SD) in the fasting state and 87 +/- 4%, 10 +/- 2% and 2 +/- 1% with food.

  2. Other primary study, N Z Med J, 1985, PMID 3861972 Study · negative

    The light meal appeared to have little effect on selenite-Se absorption, and orange juice appeared even to assist it.

Where the sources disagree

Built from every credited researcher and cited study on each claim.

Leaning for

Selenium supplements are worth taking.

Supports it 1 source
Partly 2 sources

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Timing is half the equation

You know when to take Selenium. A free account opens the interaction warnings for your whole stack. Pro adds chat about your own situation, drawn from 3,700+ hours of recorded interviews with 380 researchers and doctors, plus 48,500+ research studies.

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