The Study
Selenium supplementation affects the retention of stable isotopes of selenium in human subjects consuming diets low in selenium
This study gave people different amounts of selenium and watched how their bodies handled a special kind of selenium tracer. It found that more selenium pills changed where the tracer showed up in the blood — but it didn't check if people felt better, got sick less, or lived longer.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
People who eat very little selenium took selenium pills for five months to see if their bodies stored more of it.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 555 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even with daily supplements, the body didn't build up more selenium stores — it just moved it around in the blood, suggesting it's adapted to low intake and won't store extra.
- 2Those who took 30 μg/day stored less of the tracer selenium in their blood plasma than those who took nothing.
- 3Their bodies moved the selenium from one protein (selenoprotein P) to another (albumin), but didn't store more in red blood cells or platelets.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
British Journal of Nutrition
Year
1999
Authors
J. Finley, A. Duffield, P. Ha, R. A. Vanderpool, C. Thomson
Related Content
Claims (6)
Selenium stays in human tissues for weeks because it becomes part of selenoproteins instead of being quickly removed from the body.
Taking selenium supplements at 10–40 micrograms per day for five months changes how selenium is distributed in the blood, increasing its presence in albumin and decreasing it in selenoprotein P, while leaving levels in red blood cells and platelets unchanged.
Adults eating a diet low in selenium who take 30 micrograms of selenium as selenomethionine daily for five months show lower retention of a stable selenium tracer in plasma proteins than those taking a placebo, indicating a change in selenium metabolism without restoring critical selenium stores.
Taking selenium supplements up to 40 micrograms per day for five months does not increase how much stable selenium is retained in red blood cells or platelets when dietary selenium intake is low.
When adults with low selenium intake take selenium supplements for five months, their bodies do not retain more of a labeled selenium tracer, showing that long-term low intake reduces the ability to store additional selenium.
Taking selenomethionine for five months does not increase the total amount of selenium retained in the blood or cells, even though selenium shifts between different blood proteins.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.