Selenium (including L-selenomethionine) and Pregnancy

Here's what the available research indicates:

The Research Evidence

Pillser's research database contains 1 study on selenium and pregnancy complications — a 2025 comprehensive review of micronutrients and female fertility. The finding was beneficial, noting that deficiencies in micronutrients like selenium have been associated with an increased risk of pregnancy complications¹.

What This Means for L-Selenomethionine

L-selenomethionine is an organic (food-derived) form of selenium that is well-absorbed by the body. The available research points to selenium's general importance during pregnancy, but it's worth keeping a few things in mind:

1. The evidence is limited — the one study available is a review article, not a large-scale clinical trial specifically testing L-selenomethionine in pregnancy.
2. Deficiency vs. supplementation — the research suggests that deficiency in selenium is linked to higher risk, not necessarily that extra supplementation beyond normal levels provides additional benefit.
3. Form-specific data — there isn't specific research in Pillser's database on L-selenomethionine alone for pregnancy outcomes.

Bottom Line

The research suggests that maintaining adequate selenium status during pregnancy is likely beneficial. However, the evidence for routine supplementation with L-selenomethionine — especially if you are not deficient — is not robust enough to confidently say it will reduce complications.

Important: Selenium has a narrow safety margin — excessive intake can be toxic. During pregnancy, it's especially important to discuss supplementation with your healthcare provider, who can assess your dietary intake and potentially test your selenium levels before recommending any specific form or dose.

Footnotes

1. Pillser research database, Selenium and Reduced Risk of Pregnancy Complications ↩