The Five Nutrients That Matter Most Before You Conceive

By Tina Chagoury, Clinical Dietitian · 5 min read · 2026-09-21

A woman entering pregnancy already deficient in any of these faces a harder road. Two of the five are rarely discussed at all.

If a woman enters pregnancy already deficient in certain nutrients, she faces a more difficult path. Not necessarily danger, but a higher risk of miscarriage and greater risk to the baby's development.

These are the five that matter most, and two of them are rarely discussed.

1. Folate

The one everybody knows, and rightly so. It is essential in the formation of the baby's nervous system.

There is a distinction worth understanding, because women get confused by the labels.

Folate is the natural form of this nutrient.

Folic acid is the synthetic form used in most supplements and in fortified foods.

Methylfolate is the already activated form.

For some women, the activated form is the better choice, particularly where there are known difficulties converting folic acid. This is worth discussing with your clinician rather than guessing, but it is a real distinction and not marketing.

2. Choline

This is the one almost nobody talks about, and it deserves far more attention.

Choline is found in the highest concentration in egg yolk. That is by some distance the best food source.

Which creates an obvious problem: some women do not eat eggs, are allergic to eggs, or simply dislike them. In those cases we need a supplement that actually contains a meaningful quantity of choline, and many prenatal formulas contain very little or none at all.

Check the label. It is frequently missing.

3. Iodine

Iodine is essential, and deficiency is relatively uncommon, which is part of why it gets overlooked.

But when a woman is deficient in iodine, conceives, and the deficiency is not identified, studies have found an association between her iodine status and the child's later IQ.

That is a striking finding, and it is the reason iodine belongs on this list despite being less common.

4. Omega-3, specifically DHA

The same relationship has been found here. Studies link DHA, the specific omega-3 found in fish oils, to cognitive outcomes and IQ in the child.

This is one of the clearest arguments for adequate oily fish intake, or appropriate supplementation, before and during pregnancy.

5. Iron

Iron requirements rise substantially in pregnancy, and many women enter pregnancy already depleted.

The number to check is ferritin, which measures your stores, not only haemoglobin, which can look acceptable while stores are empty. Ask for ferritin specifically.

Absorption improves considerably when iron is taken with vitamin C, and is reduced by tea, coffee and calcium taken at the same time.

Why before rather than during

The reason to address this before conception is simple. The systems that depend on these nutrients begin forming very early, often before a woman knows she is pregnant.

Correcting a deficiency takes months, not days. Starting a prenatal supplement after a positive test is better than nothing, but it is not the same as arriving with full stores.

What I would test

Ferritin and full iron studies, vitamin D, B12, folate, thyroid function including antibodies, and blood sugar including fasting insulin.

Then supplement based on what the results actually show, rather than on what a generic prenatal happens to contain.

This article is nutrition education, not medical advice. Preconception and pregnancy care belong with your doctor.

Tina Chagoury is a licensed clinical dietitian specialising in women's hormonal health across all life stages, and the creator of the Hormone Reset Method™. Learn more and start here.