Supplements and diet before IVF: distinguishing between what’s proven and what’s marketed

When a patient sends me her list of supplements, it often includes eight or ten items, bought online, costing a hundred euros a month. Most have never been shown to have any effect on birth outcomes. Here’s a breakdown, distinguishing between what is recommended by health authorities, what is plausible, and what is pointless.

What is recommended, without question

Folic acid, 400 micrograms a day, at least one month before conception and throughout the first twelve weeks. It reduces the risk of neural tube defects. The dose increases to 5 mg per day in cases of a history of such defects, diabetes, obesity or certain treatments. This is not a ‘fertility’ supplement: it is a public health measure, and it is the only one that is non-negotiable.

Vitamin D, if a blood test shows a deficiency — which is the case for the majority of women in France during winter. Correcting a deficiency is justified in its own right; the link with pregnancy rates is suggested but not proven. Have your levels tested rather than taking supplements blindly.

Iodine, which is often deficient, and ferritin in cases of anaemia or heavy periods.

What is plausible but not yet established

Coenzyme Q10, 200 to 600 mg per day, studied in women with reduced ovarian reserve. A few trials show an improvement in the number of eggs retrieved; data on live births are insufficient. It is well tolerated. If you choose to take it, start at least two to three months before egg retrieval, to allow time for follicular maturation.

Myo-inositol in polycystic ovary syndrome: improvement in metabolic parameters and, in some cases, menstrual cycles; limited data on births. See the article on PCOS.

Omega-3s and a Mediterranean-style diet: observational studies show a favourable association, though no causal link has been established. There are no drawbacks to eating this way.

For men: zinc, selenium, vitamins C and E, L-carnitine. The most recent Cochrane review concludes that the level of evidence is weak. Three months of giving up smoking will have a greater effect than any supplement. The article on semen analysis details what works.

What is useless, or worse

DHEA: recommended for low levels, but with conflicting data and genuine androgenic effects — acne, excessive hair growth, deepening of the voice. Do not take it without a prescription and without medical supervision.

Megadoses of vitamins, particularly vitamin A: high doses of vitamin A are teratogenic. Check the ingredients of any ‘pregnancy-specific’ multivitamin complex purchased outside a pharmacy.

Fertility herbal teas and plants — chasteberry, maca, black cohosh: possible interactions with hormone treatments, no evidence of effectiveness. Always tell your doctor what you are taking, including anything that is ‘natural’.

What matters more than any supplements

Giving up smoking, for both partners: it reduces ovarian reserve, impairs sperm quality and lowers IVF success rates by about a third. Alcohol: should be significantly reduced. Weight: a very high or very low BMI reduces the chances of success and increases the risk of complications; a weight loss of 5–10 per cent in overweight women often restores ovulation. Sleep and moderate physical activity, without overdoing it — overtraining disrupts cycles.

These changes are less straightforward than placing an online order, because they take time and cannot simply be ticked off a list. They are also the only ones whose effects have been measured.

A note on the sense of control

Many women take these supplements less out of conviction than to do something during a time when they feel they have no control over anything. I understand that perfectly. But it’s important to realise that nothing you’ve eaten has caused a failed transfer. This line of reasoning, turned against oneself after a negative result, does a great deal of harm and has no basis in fact.

Frequently asked questions

Source: https://fertilitegrece.com/en/blog/diet-supplements-fertility/ — Triada Baloukoudis, IVF patient coordination in Greece. General information, not medical or legal advice. Printed on