11/13/2025
“Iodine is best known for its role in thyroid health, but new research shows how it has a direct influence on the ovaries.
A 2025 pilot study in Scientific Reports looked at women with diminished ovarian reserve (DOR) — a condition marked by fewer and lower-quality eggs. Ten participants completed two IVF stimulation cycles: the first with no nutritional intervention, and the second after a two month protocol of supplementing 150 mcg of iodine/day.
After supplementation, iodine levels rose from borderline to optimal — and the difference in ovarian function was striking. The number of mature (metaphase II) eggs increased by nearly 70%. The surrounding cumulus cells (which nurture the egg) showed far fewer signs of cell death — apoptosis dropped from 64% to 23% — while markers of healthy cell growth tripled.
In plain terms, iodine appeared to create a more favorable environment for egg development. Researchers hypothesize that its antioxidant and DNA-repair roles may protect these delicate cells during follicle maturation.
Although diminished ovarian reserve can sound like a hopeless diagnosis, this study shows that nutrition — in this case, iodine — can meaningfully influence ovarian function and egg quality. What’s striking about these results is that they were observed even with a low dose of iodine.
As I write about in Real Food for Fertility, about half of women in the US have suboptimal iodine status, and this is associated with delays in conception. While this is a small pilot study, this adds to the growing body of research on iodine’s role in fertility.
Top food sources of iodine include seafood (like fish, shellfish, and seaweed), dairy, and eggs. To learn more about the vital role of iodine in fertility and nuances with assessing iodine status & supplementation, read Real Food for Fertility (comment SPARK). And don’t skip the chapter on egg quality!
PMID: 41044113”
