Is it safe to be vegan while pregnant or breastfeeding?

The objection

“What adults eat is their own business, but a baby in the womb has no say. Most studies of vegan pregnancy find smaller babies, Germany’s own pregnancy guidance now tells vegan women to consider changing diet before they conceive, and a breastfed baby whose mother runs short of B12 can suffer harm to the brain that never fully heals. Why take that risk for a principle?”

The answer

Dietitians of Canada says a vegan diet is “even healthy for pregnant or nursing mothers” [1]. The Irish and UK dietitians’ bodies write of plant-based diets, a term both of their fact sheets define broadly enough to take in a vegan one, and neither sheet names pregnancy: INDI says a well-planned plant-based diet “can be nutritionally adequate for all stages of life” [2], and the British Dietetic Association says plant-based diets “can support healthy living at every age and life stage” [3]. Others are more guarded. The US Academy of Nutrition and Dietetics’ current position, from 2025, covers only adults who are not pregnant or breastfeeding [4]. Its 2016 position, now replaced, did call well-planned vegan diets appropriate in pregnancy and lactation [5], and recent papers still repeat the Academy’s older all-stages wording [9][13]. In 2024 the German Nutrition Society said that, with the data still limited, it could make no clear recommendation either for or against a vegan diet in pregnancy or breastfeeding, and strongly advised counselling from qualified professionals [6]. Germany’s nationwide Healthy Start Network, whose 2026 pregnancy recommendations are backed by the country’s professional societies, goes further. It says vegan women should consider switching to a vegetarian, pescatarian, flexitarian or omnivorous diet before they conceive, and that those who stay vegan should get qualified advice as soon as they start trying for a baby and have their critical nutrients checked by a doctor during pregnancy. It also reports that Switzerland and Austria still do not recommend a vegan diet in pregnancy (Alaze-Hagemann et al., 2026) [29].

On birth size the objection has a point. Most studies of vegan pregnancy find the babies smaller on average, by about 100 g in the largest and by 240 to 313 g in two small ones, though not all do. Since every one of them is observational and most are small, none can show that the diet itself is the cause. They do point to where the risk may lie, in mothers who start pregnancy with a low BMI, gain too little weight or eat too little protein, and those are exactly what a planned vegan pregnancy has to get right.

Are babies of vegan mothers smaller at birth?

Babies of vegan mothers are smaller on average, by about 100 g in the largest study, and more of them are born small for their gestational age [7]. That study comes from Israel’s public family health centres, which followed 1,198,818 babies born from 2014 to 2023, 3,338 of them from vegan households (Avital et al., 2026) [7]. Before any adjustment, 11.0% of the babies from vegan households were small for gestational age, against 7.4% from vegetarian and 6.6% from omnivorous households, and 6.1% had a low birth weight, against 4.6% of babies from omnivorous households [7]. In the first 60 days more of them were underweight for their length (7.2% against 4.7%; adjusted odds ratio 1.37, 95% CI 1.15 to 1.63) [7]. By about two years old, underweight no longer differed significantly (1.1% against 0.8%), and stunting, which had been similar from the start, was 3.9% against 3.1%, again not a significant difference [7]. The authors concluded that babies from vegan households had growth patterns similar to those from omnivorous ones, and called the findings reassuring [7]. The study recorded each family’s diet only after the birth, had no data on what the mothers ate or weighed before pregnancy, and lacked a two-year measurement for 37% of the children [7]. Its lead author disclosed volunteering for an Israeli nonprofit that advocates plant-based nutrition [7].

A 2024 systematic review found only six studies of vegan pregnancy. It reported a significantly lower birth weight for babies of vegan mothers and mixed results for small-for-gestational-age births, and said the studies had too little statistical power for firm conclusions (Meulenbroeks et al., 2024) [9]. A 2025 meta-analysis pooled three studies from Denmark and Israel, with 18, 60 and 234 vegan mothers, and found an odds ratio of 2.71 for a baby small for gestational age (95% CI 1.24 to 5.95), worked out from the raw counts and so not adjusted for the mothers’ age, weight or anything else (Papadopoulou et al., 2025) [8]. It found no clear difference in low birth weight (odds ratio 2.12, 95% CI 0.59 to 7.65) or gestational diabetes (0.64, 95% CI 0.37 to 1.11) [8]. In one of the three, a Tel Aviv study, 7 of 60 vegan mothers had a small-for-gestational-age baby against 2 of 112 omnivores (relative risk 5.9, 95% CI 1.2 to 21.8), and their babies weighed 3,015 g on average against 3,328 g (Avnon et al., 2021) [8][28].

Not every study finds a gap. The same meta-analysis describes a 2014 US survey in which the 47 vegan mothers had the heaviest babies of any group and none of low birth weight [8], and at the Coombe Hospital in Ireland, 68 vegan women recorded from 2022 to 2024 had babies with a median birth weight of 3,390 g, against 3,410 g for 10,270 women on an unrestricted diet, with no significant difference in premature birth either (Abdelrahman et al., 2026) [13]. In a small German study that followed women from early pregnancy between 2019 and 2022, 32 vegans who took B12, iodine, vitamin D and omega-3 supplements showed no significant difference from 13 omnivores in any newborn or maternal outcome measured. Its authors call it underpowered and say differences between the groups at the outset limit the comparison, and half of its eight authors list Germany’s Research Institute for Plant-Based Nutrition among their affiliations (Koeder et al., 2026) [31].

Two explanations recur, and neither is settled. The first is the mother’s own weight: a low pre-pregnancy BMI is a recognised risk factor for a small baby [7], the vegan women at the Coombe had a lower median BMI (24.3 against 25.8) [13], and in the Tel Aviv study the vegan mothers gained less weight in pregnancy (11.6 kg against 14.3 kg) [28], while gaining too little is linked with small babies [9]. In an Israeli web-based survey of 234 vegans, 10.3% had a small-for-gestational-age baby against 6.4% of omnivores [8], and the adjusted odds ratio of 1.74 (95% CI 1.05 to 2.86) moved to a similar but no longer significant 1.59 (95% CI 0.95 to 2.65) once the mothers’ BMI was added, from which the authors concluded that BMI mediated the link (Kesary et al., 2020) [9][10]. The same vegan mothers were less likely to gain too much weight (24.7% against 35.6% [8]; adjusted odds ratio 0.61, 95% CI 0.44 to 0.86 [10]). Mediation does not clear the diet, though. If eating vegan is what leaves a mother lighter or gaining too little, the diet is still on the path to a smaller baby, which is why weight gain belongs in the plan below.

The other explanation is protein. In the Danish National Birth Cohort, recruited from 1996 to 2002, the 18 vegan mothers got 10.4% of their energy from protein against 15.4% for omnivores, about half were below the Danish recommendation, and their babies were 240 g lighter after adjustment (95% CI 30 to 450 g), a gap the authors compare with that seen for daily smokers in the same cohort (Hedegaard et al., 2024) [11]. They also caution that vegans then may have eaten differently from vegans today [11]. In a 2026 secondary analysis from the same Tel Aviv hospital, by several of the 2021 study’s authors and so probably not independent confirmation, 54 vegan women ate 60 g of protein a day against 82 g for the other women, and a higher share of protein in the diet went with a lower risk of a small baby (Dubinsky et al., 2026) [12]. The Danish cohort also found pre-eclampsia in 2 of its 18 vegan mothers (11.1%, against 2.6% of omnivores), which its authors say needs replication, since two studies with more vegans found no rise in blood-pressure disorders [11].

Which supplements do you need in a vegan pregnancy?

A vegan pregnancy needs the supplements every pregnancy needs, plus reliable vitamin B12, iodine and an algae source of DHA, which German, Irish and British Nutrition Foundation advice all name for vegans [15][29][30]. Food alone leaves gaps. In the 2026 Tel Aviv analysis the vegan women got less B12, vitamin D, calcium, DHA and choline from their diets than the other women, though more folate, iron and fibre (627 against 416 µg of folate, 17 against 12 mg of iron) [12]. In the Danish cohort the gaps closed for most nutrients once supplements were counted, but vitamin D still fell short for most vegans [11].

Supplement	Amount a day	What the advice says
Folic acid	400 µg	From before you conceive until 12 weeks, as for every pregnancy [14][15]
Vitamin B12	10 µg in Irish advice	Usually needed even alongside a pregnancy multivitamin [15]
Vitamin D	10 µg in UK advice, 15 µg in Irish	The UK advises it from October to March, or all year for some women, and Ireland throughout pregnancy [14][15]
Iodine	120 to 150 µg in Irish advice	In a pregnancy multivitamin, which the BDA says should give no more than 150 µg, or use an iodine-fortified plant milk [15][16]
DHA (with EPA)	200 mg of DHA in German advice; 600 to 1,000 mg of DHA and EPA if your intake has been low, in an international guideline	From algae oil for vegans [15][29]; the guideline advises starting by about 20 weeks and continuing to about 37 weeks [18]

• If you are planning a pregnancy, make sure your B12 routine is reliable now, and ask your GP which nutrients to check, B12 among them. Germany’s 2026 guidance tells vegans to get qualified advice as soon as they start trying for a baby, to correct any shortfall before conception and to have critical nutrients checked by a doctor during pregnancy [29].
• Read the label for iodine, because the BDA (2022) says many but not all pregnancy multivitamins contain it [16], and in UK supermarkets in December 2024 only 48% of non-organic plant milks had added iodine (Nicol et al., 2026) [32].
• Avoid kelp and seaweed supplements, whose iodine content varies enough to harm the thyroid, and eat brown seaweed such as kelp no more than once a week [16]. If you have thyroid disease or take thyroid medicine, speak to your GP or midwife before taking iodine, and before changing or stopping any medicine [15][16]. More on iodine for vegans.
• Check that algae omega-3 and any multivitamin are made for pregnancy and contain no vitamin A (retinol) [14][17].
• Some women need a higher 5 mg dose of folic acid, prescribed by a GP, including those with diabetes or who take medicine for epilepsy or HIV [14]. If you take any of these medicines, speak to your GP before changing or stopping them.
• Make protein a priority at every meal and snack, from tofu, tempeh, edamame, soya milk, beans, lentils and chickpeas [15]. In the later months a midwife measures your bump at each appointment to check the baby’s growth [19], so make sure they know you are vegan, and ask whether your weight gain is on track, since gaining too little is linked with small babies [9]. If worries about food or weight make it hard to eat enough, tell your midwife or GP. Beat (UK), Bodywhys (Ireland), ANAD (US), NEDIC (Canada), the Butterfly Foundation (Australia) and EDANZ (New Zealand) offer support.
• Eat calcium-rich foods two to three times a day, such as calcium-set tofu and fortified unsweetened plant milks and yogurts [15].
• Iron is checked by blood test at the first midwife appointment and at about 28 weeks, and a GP or midwife will recommend tablets if you need them [14].
• The European Food Safety Authority’s 2016 reference intake for choline in pregnancy is 480 mg a day, though the UK sets no figure [30]. In the 2026 Tel Aviv analysis the vegan women got 270 mg a day from food against 394 mg for the others [12], and most pregnancy multivitamins contain none [15], so eat edamame, beans and broccoli often [15] and, if your intake still looks low, ask your midwife, GP or dietitian about a separate choline supplement. More on choline for vegans.

B12 supplements do their job when mothers take them. Among the women in the 2021 Tel Aviv study, the babies of vegans who took B12 had cord-blood levels averaging 1,003 pg/ml, against 443 pg/ml for the babies of vegans who did not [8], and the 2024 review found that supplements seemed sufficient to optimise B12 in mothers and cord blood [9].

On DHA, most current advice says a vegan pregnancy needs a supplement, and it differs on the dose. A 2024 clinical practice guideline, written on behalf of seven medical and scientific organisations including the European Board and College of Obstetrics and Gynaecology, advises every woman of childbearing age to get at least 250 mg a day of DHA and EPA, plus at least a further 100 to 200 mg of DHA in pregnancy, and says pregnant women with a low DHA intake should get about 600 to 1,000 mg a day, a dose it reports reduced preterm and early preterm birth in randomised trials [18]. A vegan diet supplies almost none: in the 2026 Tel Aviv analysis the vegan women’s food gave them 0 g a day, against 0.07 g for the other women [12]. Ireland’s HSE tells vegans to take an EPA and DHA supplement in pregnancy, and notes that algae supplements are their only source [15]. The British Nutrition Foundation’s 2025 briefing paper says women on plant-based diets should be advised to include a reliable source of DHA, such as a microalgae supplement (Hart et al., 2025) [30], and Germany’s Healthy Start Network (2026) tells pregnant women who eat no oily fish to take 200 mg of DHA a day as a supplement [29]. New Zealand’s guidelines (2020) are more hesitant, noting that the WHO wanted more research before recommending omega-3 supplements in pregnancy [22]. There is more on omega-3 without fish.

Is it safe to breastfeed on a vegan diet?

Vegan mothers are encouraged to breastfeed, and B12 is the supplement they must not skip, because a vegan mother’s milk can run short of it [20]. British Columbia’s health service says that milk “may be low in vitamin B12” and advises asking a health care provider about B12 supplements for mother and child [20]. New Zealand’s guidelines say breastfeeding vegans “will require B12 supplements even if they are showing no signs of deficiency” [22], and Victoria’s Better Health Channel warns that a severe lack of B12 in breast milk can interfere with a baby’s brain development, while recommending that vegan mothers keep breastfeeding, ideally for two years or longer [21]. Health New Zealand calls B12 deficiency a serious condition with effects that cannot be reversed, most likely in pregnancy and while breastfeeding [23]. Iodine needs stay at 200 µg a day while breastfeeding on the European figures in the BDA’s 2022 fact sheet [16]. In the Israeli study (2026), 47.3% of vegan mothers breastfed at least partly for a year or more, against 27.4% of omnivorous mothers [7]. The baby’s own vitamin drops and first foods are covered in raising vegan children.