The number of people following a vegan diet is increasing in the UK and has been reported as comprising 1.21% of the population. This is a significant rise when compared with 0.25% reporting to be following a vegan diet in 2014.¹

This year (2022), Ipsos for the Vegan Society also found that almost half of British adults polled reported using plant milks and 58% reported including ‘at least one plant-based meat alternative’ in their diet.¹ Sales of vegan alternative food products are also on the increase, with Aldi reporting a 500% increase in sales in January 2022 compared with 2021 – and they expect a continued increase as they expand their range in response to demand.¹

In line with this, the percentage of women of childbearing age who are adopting a vegan or more plant-based diet will likely be on the rise.

POSITIVES AND NEGATIVES OF A VEGAN DIET IN PREGNANCY

Pregnancy is a critical time for both mother and child, providing a window of opportunity to lay foundations for healthy growth in the child and protecting the mother’s health. This increased intake of plant foods has the potential to have a positive effect on health. However, if swapping meat and dairy out for heavily processed and non-fortified alternatives, expectant mothers may be putting themselves and their child at risk of malnutrition.

Nutritional advice differs across the world. In the UK and many other countries, a well-planned vegan diet is not contraindicated for pregnancy or breastfeeding. However, in Germany, it is not recommended without sufficient nutritional support.²

Positives

• The positives of increased plant food intake are well documented and may well confer additional benefits to pregnant women. These may include a potentially reduced risk of preeclampsia (PE) in those following a vegan or vegetarian diet, linked with increased fibre and fruit and vegetable intake.^3,4 However, PE is a complex and multifactorial condition and so further research is warranted.
• Research has also highlighted the reduced risk factors for gestational diabetes in those consuming a more plant-based diet,⁵ although a recent Cochrane review highlights the need for more quality research.⁶

Concerns

• Those following a vegan diet may be at an increased risk of deficiency from certain nutrients, which could in turn have a negative impact on both maternal and foetal health. These deficiencies include: iron, vitamin B12, iodine, calcium, omega-3 fatty acids, zinc and vitamin D.

• B12 is of particular concern as it’s vital in foetal development and the only reliable dietary sources are from animal products or fortified foods.

• Iron deficiency during pregnancy has been associated with low birth weight and neonatal anaemia,⁷ and maternal B12 status is also noted to be a key determinant of neonatal and infant B12 status – itself an independent risk factor for neural tube defects (NTDs).⁸

• A 2021 systematic review also highlighted a risk of increased NTDs, lower birth weights and other adverse outcomes with B12 deficiency and noted a potential benefit of B12 supplementation in those in countries where animal products can be scarce and so B12 intake is low (high risk of a low-B12 intake areas).⁹ A recent study from the University of Bristol drew links between adverse maternal and infant health outcomes and low B12 intake in pregnant women. Speech and mathematical abilities in later life of the child may also be affected, though they report that more longitudinal studies are needed.¹⁰

• A recent observational study has also highlighted incidences of lower birth weights for children of vegan mothers and a higher chance of small for gestational age (SGA) babies when compared to omnivores.¹¹

• Links have also been made that suggest an increase in self-reported postnatal depression in vegetarian mothers, potentially due to micronutrient deficiencies.¹²

Table 1: UK recommended intake for some key nutrients in pregnancy for vegans

Nutrient	RDA	Vegan sources
Calcium	700mg/day	Fortified milk/yoghurt/spreads and other dairy alternatives. It’s always worth reminding pts that organic versions aren’t fortified and some popular versions like Rude health are also not always fortified. Calcium set tofu, not set with nigari. Check the label Green leafy vegetables Pulses Calcium fortified breads and cereals Dried fruit13
Iodine	200μg/day (usual adult RDA 140μg/day)	No official UK recommendations for supplementation of iodine in pregnancy, though intake is vital for baby’s brain development. The only reliable vegan sources of iodine are fortified plant milks and supplements containing <150μg/day potassium iodide or potassium iodate. Seaweed-based supplements are not recommended and excessive supplementation can be harmful.14
Omega-3 fatty acids	No official UK RDA but two portions of fish (one oily) per week guidelines = ~450mg EPA and DHA/day	Omega-3 fortified vegan foods and supplements. Rapeseed oil Walnuts Chia seeds Ground linseeds15
Iron	14.8mg/day	Fortified foods, including breakfast cereals Dried fruit, including apricots and dates Beans and pulses Dark green veg16
Vitamin B12	1.5μg/day	The only reliable vegan sources are fortified foods and supplements. Fortified foods: eat fortified foods at least twice a day, aiming for 3mcg of vitamin B12 17 Supplements: at least 10mcg daily or at least 2000mcg weekly. NB excessive supplementation with B12 can be harmful17

In addition to this, all pregnant women in the UK are advised to consider supplementation with the following:

• 400μg/day folic acid, prior to conception and up to 12 weeks into pregnancy
• 10μg/day vitamin D daily

SUMMARY

In summary, there is currently limited heterogenous research available that looks into the outcomes of a vegan diet in pregnancy. All of those following a vegan or plant-based diet are at risk of micronutrient deficiency without careful planning and in pregnant women this could potentially affect the health of mother and child.

There is a sea change happening in the world of food and amongst heightened environmental and health concerns and much needed changes to agriculture, it doesn’t look like it is going anywhere soon.

Reasons for choosing to follow a vegan diet are variable and individual, ranging from religious and moral reasons to health and environmental concerns. Those who choose to follow these diets should be supported to follow them in the safest way. As nutrition healthcare professionals we need to be well-equipped to help support clients during their pregnancies who wish to follow a vegan or more plant-based diet, especially in the midst of an unimaginably large number of self-styled nutrition ‘experts’ and influencers.

At this time, it appears that well-planned vegan diets can be safe for pregnancy and breastfeeding, but attention needs to be paid at all times to some key nutrients. These nutrients and key sources are highlighted in Table 1.

Jessica English, RD 

Jess is a self-employed, private practice dietitian with interests in IBS,
maternal and child health, and public health.

Instagram: @meals.for.motherhood

Website: www.mealsformotherhood.com 

References

1. The Vegan Society: Worldwide growth of veganism – Veganism in the UK, available online: https://www.vegansociety.com/news/media/statistics/worldwide#:~:text=The%20number%20of%20vegans%20in,150%2C000%20(0.25%25)%20in%202014. (accessed 18/04/2022)
2. Koletzko B, Bauer CP, Bung P, Cremer M, Flothkötter M, Hellmers C, Kersting M, Krawinkel M, Przyrembel H, Rasenack R, Schäfer T, Vetter K, Wahn U, Weissenborn A, Wöckel A: German National Consensus Recommendations on Nutrition and Lifestyle in Pregnancy by the ‘Healthy Start - Young Family Network'. Ann Nutr Metab 2013
3. Frederick IO, Williams MA, Dashow E, Kestin M, Zhang C, Leisenring WM. Dietary fibre, potassium, magnesium and calcium in relation to the risk of preeclampsia. J Reprod Med. 2005
4. Chunfang Qiu, Kara B Coughlin, Ihunnaya O Frederick, Tanya K Sorensen, Michelle A Williams, Dietary Fibre Intake in Early Pregnancy and Risk of Subsequent Preeclampsia, American Journal of Hypertension, Volume 21, Issue 8, August 2008
5. Streuling I, Beyerlein A, Rosenfeld E, Schukat B, von Kries R. Weight gain and dietary intake during pregnancy in industrialized countries – a systematic review of observational studies. J Perinat Med. 2011
6. AMA. Tieu J, Shepherd E, Middleton P, Crowther CA. Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus. Cochrane Database Syst Rev. 2017
7. Sebastiani G, Herranz Barbero A, Borrás-Novell C, et al. The Effects of Vegetarian and Vegan Diet during Pregnancy on the Health of Mothers and Offspring. Nutrients. 2019
8. Molloy AM. Should vitamin B12 status be considered in assessing risk of neural tube defects?. Ann N Y Acad Sci. 2018
9. Behere RV, Deshmukh AS, Otiv S, Gupte MD, Yajnik CS. Maternal Vitamin B12 Status During Pregnancy and Its Association With Outcomes of Pregnancy and Health of the Offspring: A Systematic Review and Implications for Policy in India. Front Endocrinol (Lausanne). 2021
10. Jean Golding, Steven Gregory, Rosie Clark, Yasmin Iles-Caven, Genette Ellis, Caroline M Taylor, Joseph Hibbeln, Maternal prenatal vitamin B12 intake is associated with speech development and mathematical abilities in childhood. Nutrition Research, 2021
11. Avnon T, Paz Dubinsky E, Lavie I, Ben-Mayor Bashi T, Anbar R, Yogev Y. The impact of a vegan diet on pregnancy outcomes. J Perinatol. 2021
12. Hogg-Kollars S, Mortimore D, Snow S. Nutrition health issues in self-reported postpartum depression. Gastroenterol Hepatol Bed Bench. 2011
13. BDA. Calcium Food Fact Sheet - available online at: https://www.bda.uk.com/resourceDetail/printPdf/?resource=calcium (accessed 17/04/2022)
14. BDA. Iodine Food Fact Sheet - available online at: https://www.bda.uk.com/resource/iodine (accessed 18/04/2022)
15. BDA. Omega-3 Food Fact Sheet - available online at: https://www.bda.uk.com/uploads/assets/e8fa989a-6845-4864-a87427c78b5d65d7/Omega-3-food-fact-sheet.pdf (accessed 18/04/2022)
16. BDA. Iron Food Fact Sheet - available online at: (accessed 18/04/2022) https://www.bda.uk.com/resource/iron-rich-foods-iron-deficiency.html
17. BDA. Other Sources of B12: A practical guide for dietitians - available online at: https://www.bda.uk.com/uploads/assets/5378b751-58bd-4e85-b15b360d8165a3f8/Practical-guide-other-sources-of-B12.pdf (accessed 19/04/2022)