Selenium

Selenium is a trace mineral that functions as a powerful antioxidant, protecting egg DNA from oxidative damage. It is also essential for healthy thyroid function — and thyroid disorders (particularly subclinical hypothyroidism) significantly impair fertility and increase miscarriage risk. Selenium deficiency is associated with increased miscarriage risk and reduced fertility. Just 1–2 Brazil nuts provide the daily selenium requirement — making this one of the easiest deficiencies to correct through food.

Women trying to conceive, especially those with thyroid issues, history of miscarriage, or low antioxidant diets.

100–200 mcg selenium daily. Alternatively: 1–2 Brazil nuts daily provide approximately 100–200 mcg naturally.

Antioxidant effects are immediate; thyroid benefits develop over 3–6 months.

Very safe at recommended doses. Selenium toxicity (selenosis) can occur at very high doses (above 400 mcg daily long-term) — causes hair loss, nail brittleness, and fatigue.

Do NOT exceed 400 mcg daily. If eating Brazil nuts, count them toward your total. Check your prenatal vitamin — many contain 50–70 mcg selenium.