How Nutrition Impacts Egg Quality — and What to Eat

One of the most common things I hear from women trying to conceive — particularly those over 35 — is some version of "my doctor said my egg quality isn't good." And then, often, very little guidance on what to do about it.

Here's what I want you to know: egg quality is not entirely fixed. The three months before ovulation — the period during which an egg matures — represent a genuine window of influence. What you eat, how you sleep, what you're exposed to, and how your body is functioning metabolically all shape the environment in which your eggs are developing.

This is not a guarantee. But it is an opportunity, and one that is worth taking seriously.

Why egg quality matters

Egg quality refers primarily to chromosomal integrity — whether an egg has the right number and structure of chromosomes. Poor egg quality is one of the leading causes of failed implantation, miscarriage, and difficulty conceiving. It is also strongly influenced by oxidative stress — the imbalance between free radicals and antioxidants in the body.

This is where nutrition becomes directly relevant. The right nutritional environment reduces oxidative stress, supports mitochondrial function within the egg (which powers fertilisation and early embryo development), and provides the raw materials for healthy hormonal signalling.

The most important nutrients for egg quality

CoQ10 (Coenzyme Q10)

CoQ10 is produced naturally in the body and plays a critical role in mitochondrial energy production. Mitochondria are especially dense in egg cells — they power the enormous energy demands of fertilisation and early cell division. CoQ10 levels decline with age, which is one reason egg quality tends to decrease over time. Research supports supplementation, particularly in the ubiquinol form, for women over 35.

Folate (not just folic acid)

Most women know they need folate for pregnancy, but the form matters. Methylfolate — the active form — is significantly more bioavailable than synthetic folic acid, particularly for women with MTHFR gene variants (which are more common than most people realise). Folate supports DNA synthesis and repair, both critical for egg quality.

Vitamin D

Vitamin D receptors are found throughout the reproductive system — in the ovaries, uterus, and placenta. Deficiency is associated with impaired follicular development and lower IVF success rates. Most of us in northern climates are deficient. Testing your levels before supplementing is worthwhile.

Omega-3 fatty acids

DHA and EPA — found in oily fish and algae-based supplements — are structural components of cell membranes, including egg cell membranes. They also reduce systemic inflammation, which is increasingly understood as a factor in reproductive health. I generally recommend food sources first, with supplementation where intake is insufficient.

Zinc

Zinc is essential for egg maturation and fertilisation. It's also critical for healthy progesterone production in the luteal phase. Good food sources include oysters, pumpkin seeds, beef, and legumes.

"The three months before ovulation are a genuine window of influence. What you eat now matters for the egg that ovulates in twelve weeks."

What to eat — and what to reduce

Prioritise

• Deeply coloured vegetables and fruits — rich in antioxidants that combat oxidative stress
• Oily fish (sardines, salmon, mackerel) — 2–3 portions per week for omega-3s
• Eggs — a complete protein and excellent source of choline, which supports methylation
• Nuts and seeds — particularly walnuts (omega-3) and pumpkin seeds (zinc)
• Legumes and wholegrains — fibre supports oestrogen metabolism via the gut
• Liver — the most nutrient-dense food on the planet, rich in folate, B12, iron, and zinc

Reduce or eliminate

• Ultra-processed foods — high in inflammatory seed oils and refined sugar
• Alcohol — directly impairs follicle development and increases oxidative stress
• Trans fats — associated with ovulatory infertility
• High-glycaemic foods — blood sugar dysregulation affects hormone balance

What about supplements?

I want to be honest here: the supplement industry for fertility is vast and not always evidence-based. My approach is to assess each person individually — looking at nutritional status, diet quality, health history, and specific fertility findings — before recommending supplementation. A protocol that's appropriate for one woman may be unnecessary or even counterproductive for another.

What I will say is that a high-quality prenatal vitamin is a sensible foundation for most women trying to conceive, and that targeted supplementation based on assessed need tends to be far more effective than a generic "fertility stack."

The broader picture

Nutrition is one piece of the fertility puzzle. Sleep, stress, thyroid function, gut health, and environmental exposures all matter too. In my practice, I look at the full picture — because fertility is not just about the egg. It's about the entire physiological environment in which conception is being asked to occur.

If you've been told your egg quality is a concern, or if you simply want to give yourself the best possible foundation for conception, I'd encourage you to treat the next three months as an investment period. It is one of the most evidence-supported things you can do.