Ranked by evidence
Best supplements during pregnancy
In pregnancy a handful of nutrients do real work, mainly folic acid, iron and a well-built prenatal, while most other products add little. Everything below is ranked by how strong the evidence is for this goal, not by how popular the product is. Items that only help in a particular situation, such as nausea, are labelled that way.
Picks are ranked by the strength of published evidence for this goal in otherwise healthy adults. A persistent symptom needs a clinician's evaluation, and no supplement on this list replaces treatment.
Evidence last reviewed: September 2026
Top picks
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Prenatal Multivitamin | Strong evidence | the base of everything else | A full multiple-micronutrient prenatal reduced low birthweight and small-for-gestational-age births compared with iron and folic acid alone. Check for iodine and choline, which many products miss, and do not stack it with cod liver oil or retinol. | View |
| Folic Acid (Vitamin B9) | Strong evidence | preventing neural tube defects | Cuts neural tube defects by about 70%. Take 400–800 mcg a day through the first trimester; women with a previous affected pregnancy are usually advised 4–5 mg. | View |
| Iron | Strong evidence | preventing anaemia in pregnancy | In a Cochrane review of 61 trials, daily oral iron cut maternal anaemia at term by 70% and iron deficiency by 57%. Constipation and nausea are common, and bottles must be kept away from children. | View |
Solid options
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Prenatal DHA | Moderate evidence | lowering preterm birth risk | Omega-3 in pregnancy reduced preterm birth, especially before 34 weeks, but did not improve child cognition. Trials used at least 500 mg DHA a day, more than most prenatal DHA products supply. | View |
| Choline | Moderate evidence | a gap many prenatals leave | Pregnancy calls for 450 mg a day and many prenatals contain little or none. A small trial found faster infant information processing with the higher of two third-trimester intakes. | View |
Situational
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Vitamin B6 (Pyridoxine) | Moderate evidence | nausea and vomiting of pregnancy | First-line in obstetric guidance for pregnancy nausea at 10–25 mg every 6–8 hours, alone or with doxylamine. Do not go above guideline doses, since chronic high intake can damage nerves. | View |
| Ginger | Moderate evidence | nausea, as an alternative option | A meta-analysis of 12 trials found 1,000–1,500 mg a day improved nausea, though not vomiting, with no rise in miscarriage. Higher doses are not well studied. | View |
| Iron Bisglycinate | Moderate evidence | when standard iron upsets your stomach | In pregnant women it raised haemoglobin more than other iron forms and cut gut side effects by roughly two thirds. It is still iron, so take it only with a real indication. | View |
| Iodine | Moderate evidence | if your prenatal lacks iodine | Iodine in pregnancy improves maternal thyroid markers, though benefits for the child are unproven. Aim for the 150 mcg in a typical prenatal and avoid kelp or high doses, since excess also causes thyroid disease. | View |
Popular for this goal — but the evidence says skip
- Red Raspberry Leaf Limited evidence
The only decent trial found no shorter first stage of labour and only about 10 minutes off the second, and no trial shows it brings on labour.
- Vitamin A (Retinol) Moderate evidence
Preformed vitamin A above about 10,000 IU a day is linked to birth defects, so get it as beta carotene in a prenatal rather than as retinol or cod liver oil.
- L-Methylfolate Limited evidence
Every trial that prevented neural tube defects used folic acid, and methylfolate has never been shown clinically superior, even with MTHFR variants.
- Kelp (Iodine Source) Limited evidence
Iodine content varies more than 100-fold between batches and labels are unreliable, and kelp can carry arsenic, cadmium and lead.
- Leg Cramp Formulas Limited evidence
Magnesium trials for pregnancy leg cramps are small and heterogeneous, and Cochrane rated the same evidence conflicting.
- Inositol (Myo-Inositol) Moderate evidence
Evidence for preventing gestational diabetes is low-certainty, and the Cochrane review called for larger trials before routine use.
Our verdict
Take a prenatal with folic acid, iodine and iron whose vitamin A comes mostly as beta carotene, and add DHA and choline where it falls short. Skip raspberry leaf, extra preformed vitamin A and kelp, and do not pay more for methylfolate over plain folic acid.