Selenium (selenomethionine vs selenite) and metabolic

What 2 graded rows on selenium (selenomethionine vs selenite) agree on for metabolic, and where they differ. Counted side by side, never averaged.

Consensus finder Rows from the Selenium (selenomethionine vs selenite) page, reviewed Oct 21, 2026 How it decides

What the rows agree on

Each block and row is one graded row from the Selenium (selenomethionine vs selenite) page, with its PubMed record.

Supplement

Selenium (selenomethionine vs selenite) Choose another

2 rows · 1,570 people

Split. 1 row found no difference and 1 found a worse outcome.

No difference or worse

Improved

Each block is one evidence row, sized by how many people it enrolled, with its grade inside. Red: a worse outcome.

From the rows

Trial sizeHow longWho was studiedWhen published

The best-graded row, grade C, is a randomized trial of 1,202 people (2007) and found a worse outcome.

The row that found a worse outcome was larger: 1,202 people, against 368 people for the row that found no difference.

The row that found a worse outcome ran longer (7.7 years) than the row that found no difference (6 months).

Only the row that found no difference names older adults in its population.

The row that found no difference is newer (2008) than the row that found a worse outcome (2007).

1 no difference · 1 worse

Grade CThyroid hormone levels in healthy older adults · No difference
RCT · n 368 · 2008 · Euthyroid UK volunteers aged 60-74 (baseline plasma selenium 91 microg/L)
100, 200 or 300 microg/day · 6 months
No effect on thyroid function (TSH, T3, T4) despite significant increases in plasma selenium.
Row on the Selenium (selenomethionine vs selenite) page · PubMed 18258627 (opens PubMed)
Grade CDeveloping high blood sugar over 7.7 years · Worse
RCT · n 1,202 · 2007 · Adults from dermatology clinics in low-selenium areas of the eastern US, without type 2 diabetes at baseline
200 microg/day · Average follow-up 7.7 years
Type 2 diabetes developed in 58 people on selenium vs 39 on placebo (HR 1.55; 95% CI 1.03 to 2.33), with the highest risk in those with the highest baseline selenium (HR 2.70).
Row on the Selenium (selenomethionine vs selenite) page · PubMed 17620655 (opens PubMed)