The number of British people who identify as vegan has quadrupled in the last five years (The Vegan Society, 2019). Indications are that nearly half of the vegans in the UK made the change in 2018 (Vegan Trade Journal, 2018), suggesting that veganism is not only growing, but growing rapidly. Vegans represent a small minority, constituting only 1.16% of the population (The Vegan Society, 2019) but there has been a rise in interest in ‘flexitarianism’ (Table 1) and a reduction in the consumption of meat and dairy products more generally over recent years (YouGov, 2019). Supermarkets in the UK are reporting substantial increases in the demand for plant-based options (Lupica, 2017; Sainsbury's, 2019), with Sainsbury's noting a 65% increase in sales of plant-based products year-on-year, and predicting that a quarter of Britons will identify as vegetarian by 2025 and half will identify as flexitarian (Sainsbury's, 2019). There is a need for midwives to consider the current research around nutritional guidance for this fast-growing group, in order to provide up-to-date, evidence-based direction.
| Term | Definition |
|---|---|
| Vegan | Someone who seeks to exclude animal-derived products for food, clothing or any purpose in order to avoid cruelty or exploitation of animals |
| Plant-based | A diet based mainly on foods derived from plants. Motivations often stem from pursuit of better health. Will not necessarily have objections to the use of animal products for clothing, toiletries, sport, entertainment etc |
| Vegetarian | A person who does not eat meat or fish. Usually vegetarians eat dairy, eggs, honey and other animal-derived products |
| Flexitarian | A person with a mostly vegetarian diet who occasionally eats animal products |
Background
Drivers for the widespread shift to plant-based diets stem from ethical, health and environmental arenas. Environmentally, studies indicate that animal agriculture uses the majority of the world's farmland, whilst only providing 18% of the calories consumed. Reduction or elimination of animal products may be the single biggest way to reduce environmental impact (Poore and Nemecek, 2018). Livestock farming may also contribute an estimated 18% of total greenhouse gas emissions (Food and Agriculture Organisation of the United Nations, 2006). The UK Government's Committee on Climate Change (2020) recently called on consumers to reduce their meat and dairy intake by a minimum of 20% to meet the Government's net zero target by 2025.
In addition to these environmental drivers, there is a growing body of evidence suggesting that animal products may be detrimental to human health. The World Health Organization ([WHO], 2015) reported in 2015 that it had categorised processed meat as a group 1 carcinogen and red meat as group 2A. Following this, published studies have indicated that plant-based diets may be beneficial to human health in the prevention of conditions such as diabetes and cardiovascular disease (Aune et al, 2017; Bechthold et al, 2019; Hyunju et al, 2019; Kahleova et al, 2019; Qian et al, 2019). It is easy to see how a sea-change in our approach to human nutrition is underway, and this is before ethical issues are taken into consideration.
Whilst nutrition in general is crucial in its relation to good health, maternal nutrition both during and before pregnancy is significant for its effect on the health of both mother and infant (WHO, 2016). Maternal diet impacts on an infant's immediate health, as well as on overall childhood growth and wellbeing (Geraghty et al, 2018). More significantly, epigenetic research indicates that maternal nutrition constitutes one of the environmental factors influencing the expression of genes in utero, increasing the fetus' susceptibility to chronic disease into adulthood and beyond (Mandy and Nyirenda, 2018).
It is essential that health professionals are able to adapt and respond to changing human diets with evidence-based advice, not only to assure health but to adhere to regulatory demands regarding individualised care (Nursing and Midwifery Council [NMC], 2018). Counselling individuals in relation to their nutrition is a significant part of the role of the midwife and, at present, there is an absence of clear guidance around counselling the growing number of people who identify as vegan or plant-based through pregnancy and breastfeeding.
Is it safe?
Historically, reports have surfaced expressing concerns about the nutritional sufficiency of a vegan diet through pregnancy and breastfeeding (Gambon et al, 1986; Kühne et al, 1991; Ciani et al, 2000), though these are largely attributed to case studies focusing on families following extreme and/or restrictive diets that cannot be described as ‘well-planned’. Similar concerns have been raised for extreme or restrictive omnivorous diets. The British Dietetic Association's ([BDA], 2017a) position is that a well-planned vegan diet can support health throughout the human lifecycle. This is echoed in guidance from the NHS (2018a) and the WHO (2001). However, there is an absence of direction from the National Institute for Health and Care Excellence (NICE), the Royal College of Midwives (RCM) or the Royal College of Obstetricians and Gynaecologists (RCOG) regarding plant-based diets in pregnancy and lactation.
General nutritional recommendations
NICE (2008) make reference to the importance of vitamin D and folic acid supplementation in its clinical guidance for uncomplicated pregnancies. It also recommends that all women are given diet and nutrition information at their first appointment by their midwife and directs midwives to signpost women to the Healthy Start programme for those who qualify (NHS, 2020). A maximum of an extra 200 calories per day are recommended in the third trimester of pregnancy (Start4life, 2020a), though no guideline is given for breastfeeding (Start4life, 2020b). NICE (2015) further recommends 5 portions of fruit and vegetables a day and 1 portion of oily fish a week. Specific nutritional recommendations in breastfeeding are not given, with the same general dietary guidelines recommended (British Nutrition Foundation, 2018; NHS, 2018b). The guide below discusses these recommendations in the context of a vegan or plant-based diet.
Nutritional considerations for vegans
Folic acid
Folic acid is the synthetic form of folate, or vitamin B9, essential for the formation of red blood cells. Folic acid is known to decrease the risk of neural tube defects in the fetus, and women in the UK are recommended to take a daily 400 mcg folic acid supplement when planning a pregnancy or upon discovering they are pregnant (NICE, 2008). This should be continued throughout the first trimester, while the fetal spine is formed. Women at increased risk of neural tube defects are recommended to take an increased dose of 5 mg (NICE, 2008).
Good sources of folate include dark leafy greens, legumes and beans, whole grain foods, oranges and orange juice. Vegans and those on a plant-based diet may have relatively high folate intakes compared to omnivores, particularly if they eat a varied whole-food and minimally processed plant-based diet (Schüpbach et al, 2017). However, dietary doses are variable, and, as such, vegans should be directed to supplement throughout the first trimester of pregnancy with the same dose as non-vegans.
Calcium and vitamin D
Calcium requirements may be higher in pregnancy (Kovacs, 2019) though there is no distinction in government guidelines for this, with the daily recommended intake set at 700 mg for all women between the ages of 19 and 64 years (Public Health England [PHE], 2016). Vegan calcium needs can be met in pregnancy by eating a diet that is rich in green leafy vegetables, cruciferous vegetables (such as cauliflower, cabbage, kale and broccoli), sesame seeds, almonds and dried fruit. Calcium-set or calcium-fortified products are also good sources (such as tofu, plant-based yoghurts or milks, soya products and some breads and orange juices).
Vitamin D enables calcium absorption and is mostly obtained through exposure to sunlight, where it is formulated in the skin. It is necessary for bone growth and development for mother and fetus alike. It is difficult to obtain sufficient amounts of vitamin D through diet alone. NICE (2017) guidance recommends vitamin D supplementation (10 mcg/day) throughout pregnancy and lactation from first contact with a healthcare professional. This recommendation is no different for vegan or plant-based women. However, vitamin D3 (cholecalciferol) is commonly derived from animals via grease extracted from sheep's wool. Vegans can obtain supplementation from vitamin D2 (ergocalciferol) or vegan vitamin D3, grown on lichen. Currently, ‘Healthy Start’ vitamins contain animal-derived vitamin D3.
Vitamin B12
Vitamin B12 is essential for nervous system function and deficiency can cause neurological problems and anaemia. It is even more important in pregnancy, when demands for vitamin B12 are higher (Balcı et al, 2014). Contrary to popular belief, vitamin B12 is produced by anaerobic micro-organisms, not by animals or plants. Animals are exposed to B12-producing bacteria encountered in grazing or else through supplemented feed. Historically, plants would have had similar exposure to these organisms in the soil, but modern hygiene practices combined with depletion of soil bacteria mean that plants are no longer viable sources. Vegans should therefore ideally take a daily supplement. Government guidelines suggest a recommended intake of 1.5 mcg per day (PHE, 2016) but there is no defined upper limit and no identified toxic effect associated with excess intake (Siddiqua et al, 2016). As such, supplemental doses are often much higher and vegans should be assured that either a daily (10 mcg) or weekly (2000 mcg) dose is appropriate in pregnancy (BDA, 2019). Fortified foods can be used as an alternative (such as fortified plant milks, breakfast cereals and nutritional yeast flakes), though again, dietary doses are more difficult to assure.
Omega 3
Essential omega-3 fats (alpha-linolenic acids or ALAs) are obtained through dietary sources, as our bodies cannot make them. They are converted to polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic and docosahexaenoic acids (EPA/DHA). These contribute to proper function of the immune system, brain, nerves and eyes. Good intake of omega-3s in pregnancy has been associated with a decrease in the incidence of pre-term birth and low birthweight babies (Middleton et al, 2018).
Good plant-based ALA sources include ground flaxseeds and flaxseed oil, chia seeds, walnuts and soya beans (BDA, 2019). A tablespoon of ground flaxseeds a day can be added to a smoothie, a bowl of porridge or soup to ensure a daily source. Vegans may also choose to take a DHA/EPA supplement derived from algae, rather than fish, though there is currently no research regarding the effect of algal supplementation.
Iodine
This trace mineral regulates production of thyroid hormones. A moderate to severe decrease in iodine in pregnancy can increase the risk of miscarriage, low birthweight and overall infant morbidity and mortality (Eastman et al, 2019). The impacts of a mild deficiency in pregnancy are less clear, though this has been associated with neurodevelopmental impairment and UK-based studies suggest deficiency is becoming more common (Bath et al, 2014; Knight et al, 2017).
Vegans can obtain iodine through dietary sources, such as nuts, cereals, grains, bread and fortified plant milks. It is also present in variable quantities in fruits and vegetables, though this depends on the amount in the plant's soil. Iodine is also found in many pre-natal vitamin formulations, though not all and notably not in the formulation given out to those receiving Healthy Start vouchers. Vegans (as well as non-vegans) can take a daily pregnancy multi-vitamin and check that they are taking a formulation that includes iodine. This may be listed as ‘potassium iodide’ in the vitamin ingredient listing and should ideally meet the agreed minimum 150 mcg recommendation (BDA, 2016a). Regular consumption of iodine-containing seaweeds, such as kelp, should be avoided, as doses are variable and can easily result in excessive intake, which may impair thyroid function (Leung and Braverman, 2014).
Iron
Iron deficiency is a cause for concern in pregnancy, in view of increasing iron requirements making anaemia a common occurrence; prevalence in pregnant UK women is nearly 1:4 (Barroso et al, 2011). This becomes even more significant for women carrying twins or multiples, when iron needs are increased and anemia is more common (NICE, 2019). The iron content of vegan and plant-based diets may be higher than omnivorous diets (Collings et al, 2013); however, the iron is derived in a non-haem form. This can be more difficult to absorb than the haem form in animal products and, whilst non-haem forms are protective against iron overload and cardiometabolic disease, higher iron intake for vegans is generally indicated.
Iron-rich foods in a vegan diet include wholegrain foods, soya products, beans, nuts, seeds and green leafy vegetables (also high in essential zinc). It is also notable that cooking and/or eating iron-rich foods with vitamin C-containing foods (such as broccoli, peppers, tomatoes, oranges) may considerably increase absorption of iron.
Protein
The BDA (2016b) advise eating two daily portions of protein-rich foods during pregnancy. Plant-based sources of protein are numerous, with most whole plant foods containing some protein. As long as a varied and plant-based diet is followed that meets calorific needs, protein requirements will usually be met without issue (Schüpbach et al, 2017). Plant-based foods with the highest amounts of protein include beans, peas, lentils, tofu, nuts and nut butters and seeds. Plant-based meat alternatives, such as Quorn or soya-based burgers and sausages, may also contain high levels of protein. However, as with their counterparts that contain meat, these are often highly-processed, containing high levels of salt and fat and should either be avoided or eaten in moderation.
Vegans and infant feeding
Nutrition in breastfeeding
Largely, the same nutritional guidance stands during both pregnancy and lactation, with three main exceptions; the requirements for protein, zinc and calcium are markedly increased when breastfeeding and these requirements may be increased even further for those carrying twins or multiples, though research on this is scant. The recommended daily intake of protein is 11 g when breastfeeding (increased from 6 g during pregnancy) (Committee on Medical Aspects of Food and Nutrition Policy, 1991), though these requirements decrease after six months. Similarly, zinc requirements increase from 7 to 13 mg per day when breastfeeding, falling to 9.5 mg per day from four months onwards. Helpfully, most protein-rich, plant-based foods are also rich in zinc, and consuming a reliable intake of wholegrains, soya, beans, nuts and green leafy vegetables should easily meet the needs of a vegan woman through pregnancy and lactation. Vegans may also wish to adopt food preparation techniques that decrease phytate content, as this may impair zinc absorption (King, 2000). Such techniques include soaking beans before cooking them, as well as eating fermented foods, such as sauerkraut.
Calcium needs increase from 700 to 1250 mg per day during breastfeeding (BDA, 2017b) and it is crucial that vegan breastfeeding women are aware of this increase, so that calcium-rich foods can be added to the diet. Examples of portion-based calcium-rich plant-based foods based on BDA (2017b) guidelines are given in Table 2.
| Food (portion) | Calcium content (mg) |
|---|---|
| Calcium-set tofu – 60 g | 200 |
| Calcium-fortified soya yoghurt – 125 g | 150 |
| Calcium-fortified plant-milks (eg soya, oat) – 100 mls | 120 |
| Dried figs – 30 g | 75 |
| Almonds – 30 g | 72 |
| Broccoli – 100 g | 47 |
As with non-vegans, vegans should be encouraged to supplement exclusively-breastfed babies with 8.5-10 mcg vitamin D daily (Scientific Advisory Committee on Nutrition, 2016) but, as with pregnancy multivitamins, many contain vitamin D derived from an animal source. There are commercially available brands that contain plant-based vitamin D2. However, parents may wish to be aware that, whilst these are suitable from birth, they may be in a ‘multivitamin’ format and contain vitamin supplementation of vitamins A and C in addition to D. Vegan mothers who are breastfeeding should also be encouraged to continue taking a daily multivitamin themselves to ensure sufficient vitamin B12 and iodine levels in breastmilk.
Formula feeding
Vegans who choose not to breastfeed may need to know that there are currently no commercially available vegan infant formula milks on general sale in the UK. Whilst there are milks that do not contain animal protein, the vitamin D within these products is derived from animals (First Steps Nutrition Trust, 2020). Therefore, many vegans will choose to breastfeed their babies and start them on an unsweetened calcium-fortified plant-based milk (such as soya, oat or nut milk) from the age of one year old. This will provide nutritional parity to infants commencing on whole cow's milk (First Steps Nutrition Trust, 2017).
Conclusions
Vegan and plant-based lifestyles are becoming more popular and, with environmental and political drivers, they are likely to become more so. It is imperative that midwives provide women and families with evidence-based nutritional advice to support them through pregnancy and infant feeding, particularly when considering the influence that good nutrition can have on health and disease-prevention into adulthood and beyond. Well-planned vegan diets are healthy in pregnancy and breastfeeding, and professional nutritional advice is very similar to that given to non-vegans; no extra supplementation is required if a broad multivitamin is used. However, midwives may wish to familiarise themselves with plant-based sources of major nutrients, so they can ensure vegans are consuming foods rich in these and are increasing intake of protein, zinc and calcium when breastfeeding.