Vegan or Vegetarian and Trying to Conceive: The B12, Iron, Iodine, Choline, and DHA Gaps to Cover

Short answer: you don't need to eat meat to get pregnant or have a healthy pregnancy, but vegans and many vegetarians need to cover five nutrients deliberately: vitamin B12, iron, iodine, choline and DHA. B12 is the non-negotiable one, since plant foods don't naturally contain it. The other four are about planning: choosing the right foods, checking your prenatal's label, and asking for a few specific blood tests before you start trying.

This checklist is for both partners. Most of the pregnancy-specific numbers apply to the person who will carry the pregnancy, but B12, iron and zinc status matter for sperm production too.

The five-nutrient checklist

1. Vitamin B12: the one you can't skip

The NIH Office of Dietary Supplements (ODS) is clear that vegans, and vegetarians who eat no meat, have a higher risk of B12 deficiency because B12's natural sources are animal foods. Plant foods don't naturally contain it. (Fermented foods like tempeh contain only trace amounts.)

The adult RDA is 2.4 mcg a day, rising to 2.6 mcg in pregnancy and 2.8 mcg while breastfeeding. ODS notes that B12 deficiency during pregnancy and breastfeeding has been linked to neural tube defects, developmental delays and anemia in children, and that breastfed infants of mothers who eat no animal products may have very limited B12 reserves.

How to cover it

• Fortified foods (some breakfast cereals, plant milks and nutritional yeasts) count, and ODS describes fortified cereals and nutritional yeasts as highly bioavailable sources. Check labels; not every product is fortified.
• Supplements are the most reliable route. ODS notes absorption is about 50% at small doses but drops sharply at higher ones (about 2% at 500 mcg), which is why high-dose products exist. It also says there's no evidence that one supplement form absorbs better than another, and that sublingual and oral forms work equally well.
• Your prenatal probably contains some B12. Check the amount and whether you need more on top; that's a question for your clinician, especially if you've been plant-based for years.

2. Iron: more needed, less absorbed

ODS states that iron requirements are 1.8 times higher for people following vegetarian diets, because the non-heme iron in plants is less bioavailable than the heme iron in meat. The RDA for women 19 to 50 is 18 mg a day, rising to 27 mg in pregnancy.

Absorption tips that are backed by ODS

• Pair iron-rich plants with vitamin C: lentils with tomato, tofu with peppers, fortified cereal with fruit.
• Phytates in grains and beans reduce absorption. Soaking, sprouting and fermenting help, and so does variety.
• Calcium may reduce iron absorption, though ODS says this effect hasn't been definitively established. If you take a separate calcium supplement, ask whether to space it from iron-rich meals.

Don't start a high-dose iron supplement on a hunch. Ask for ferritin (iron stores) and a complete blood count first. Our guide to iron deficiency and fertility explains what those results mean.

3. Iodine: the quiet gap

Iodine supports thyroid hormone production, which matters for conception and fetal brain development. ODS lists vegans and people who eat few or no dairy products, seafood or eggs among groups at risk of low intake, along with people who don't use iodized salt. The RDA is 150 mcg a day for adult women and 220 mcg in pregnancy.

The American Thyroid Association recommends that people who are planning a pregnancy, pregnant or breastfeeding take 150 mcg of iodine a day as potassium iodide. That's where many prenatal labels fall short. ODS cites an analysis of 59 best-selling prenatal multivitamins in which only 34 contained iodine. If your prenatal lacks iodine, ask your clinician about the best way to add it.

Iodine also has an upper limit (1,100 mcg a day for adults, per ODS). Seaweed products can be very high and variable, so they're not a reliable everyday source.

4. Choline: often missing from prenatals

Choline supports fetal brain and spinal cord development, and eggs are one of its richest sources, which leaves vegans in particular with a gap. Plant sources include soy foods, legumes, quinoa, and cruciferous vegetables like broccoli and Brussels sprouts, but reaching recommended amounts from plants alone takes planning. Many prenatals contain little or no choline, so check yours. Our guides to choline as a missing fertility nutrient and choline on prenatal labels go deeper.

5. DHA: algae oil vs. fish oil

DHA is an omega-3 fat important for fetal brain and eye development. Plant foods like flax, chia and walnuts provide ALA, a shorter omega-3 that the body converts to DHA only in small amounts. Fish get their DHA from the algae in their food chain, which is why algae oil is the plant-based way to get preformed DHA directly. It also sidesteps concerns about mercury and avoids the vitamin A found in cod liver oil (see our vitamin A label guide). Our omega-3 and DHA guide compares forms.

Don't forget zinc and vitamin D

Two more nutrients are worth a glance. Plant zinc is absorbed less efficiently because of phytates, which matters for both partners; our post on zinc and sperm health covers food strategies. Vitamin D depends more on sun exposure and supplements than diet for most people, vegan or not, and many vegan D supplements use lichen-derived D3. Ask whether a level check makes sense.

Bloodwork to ask about before trying

1. Vitamin B12 status. Your clinician may add other markers if the result is borderline.
2. Ferritin and complete blood count for iron stores and anemia.
3. Thyroid function (TSH), especially if your iodine intake has been low.
4. Vitamin D, if your clinician thinks it's useful.
5. A supplement review. Bring every bottle, or use our supplement list template.

For a full pre-conception timeline, howtohaveababy.com's 90-day preconception checklist covers the non-nutrition steps, conceiveguide.com's evidence-based fertility diet covers the research on overall eating patterns, and fertilestart.com's fall nutrition reset has practical meal ideas.

Choosing a vegan or vegetarian prenatal

• Folic acid or folate, plus B12 in a meaningful amount.
• Iodine, ideally as potassium iodide.
• Iron, unless your clinician has advised an iron-free version.
• Choline, or a plan to get it from food or a separate product.
• Algae-based DHA, either included or taken separately.
• Vegan certification if gelatin capsules or animal-derived vitamin D3 matter to you.

Supplements don't treat infertility. They fill nutrient gaps. Review any new supplement with your clinician, and if you've been trying for 12 months (or 6 months at 35 or older), ASRM recommends a full evaluation.

Sources

• NIH Office of Dietary Supplements. Vitamin B12: fact sheet for health professionals (updated July 2, 2025). ods.od.nih.gov
• NIH Office of Dietary Supplements. Iron: fact sheet for health professionals (updated September 4, 2025). ods.od.nih.gov
• NIH Office of Dietary Supplements. Iodine: fact sheet for health professionals (updated November 5, 2024). ods.od.nih.gov
• ASRM Practice Committee. Definition of infertility: a committee opinion (2023). asrm.org (PDF)