Recently, I had a discussion with a colleague about the effects of a vegan diet on child development. Being a vegetarian for more than a decade and eating almost vegan in recently, and not having a child yet, I had some feelings about the topic but little knowledge. Thus, the “discussion” was essentially a monologue with me listening to my colleague’s opinion.
In such situations something in me shouts “Check the scientific literature!” and, guess what, I couldn’t resist. But before I tell you a summary of what I’ve learned, first a
Disclaimer: I’m not an expert on the topic and my knowledge is entirely derived from scientific articles and reviews. Although I think that I’ve gained a fairly comprehensive overview of the current state of knowledge, you should consult an expert for any medical advice.
Ah, and feel free to read the articles yourself! Most of them are open access, they are neither rocket science nor quantum mechanics (unfortunately) and some of them even include practical guidelines or instructions. In the bibliography I’ve added short notes about why an article might be interesting to read for you.
General remarks
There are some studies on the effects of a vegan diet on children, but the older studies have two drawbacks: On the one hand, their sample size is typically small because there were only few vegan parents. On the other hand, diet habits have changed in the last decades, new (ready-made) vegan food and drinks are being sold and information about vegan diets is readily available on the internet, both from scientific studies and experiences of others. Hence, vegans today are better informed about possible problems with their (and their children’s) diets than they were in the past. The major part of the scientific knowledge about a vegan diet is, however, based on studies with adults. These studies show general health benefits, e.g. regarding ischemic heart disease, type 2 diabetes, obesity or cancer. Unfortunately, the results of studies of vegan adults are not immediately transferable to infants and children because of the special nutritional needs during child development.
If you do let your children eat animal products, you should care about their diet. If you do not let your children eat animal products, you have to care about their diet!
Pediatric societies of different countries have different recommendations. It seems to me that the consensus in the literature is that a well-designed vegan diet works and may be beneficial. The main concern is that every restriction in the diet increases the risks of nutritional deficiencies and that these risks need to be addressed. Or, in other word: If you do let your children eat animal products, you should care about their diet. If you do not let your children eat animal products, you have to care about their diet! The younger the children, the higher the risk. Some case reports in the literature show examples of problematic child development, but these cases were rooted in bad diet choices as well as resistance to regular checkups and expert support. Such an ignorance is always problematic, independent of whether you reject animal products or not. 1
That being said, there is still some lack of knowledge on the topic, although it seems to me like a coherent understanding of the effects of a vegan diet on children will emerge in the next few years. What makes the studies a bit tricky is that vegans have, on average, a healthier lifestyle and higher socioeconomic status. That transfers to how they feed and treat their children and needs to be taken into account when comparing to other groups. Also, the bioavailability of nutrients (how well the body can absorb and use the nutrient) can be different in plant-based food as compared to animal-based food. Hence, it is not enough to measure the intake of macronutrients (protein, carbohydrates, fat) and micronutrients (vitamins, minerals) but the status of these nutrients in the body needs also to be tested. Such testing has some pitfalls and it makes studies much more demanding in time and effort for the scientist and the participants.
Potentially critical nutrients
Typically, studies distinguish three diets:
- Vegans with a diet without animal products.
- Vegetarians with a diet containing animal products like eggs and dairy, but without meat and fish consumption.
- Omnivores with a diet that consists of plant- and animal-based products including meat and fish.
Potentially critical nutrients are
- for vegetarians iron, zinc, iodine, selenium, n-3 fatty acids, and vitamin D, and,
- for vegans, additionally vitamin A, vitamin B12, calcium, vitamin B2, and protein (total intake and some essential amino acids).
It is also necessary to differentiate between babies/infants and children/adolescents, as children have dietary needs that depend on their age. So, let’s go through the potentially critical nutrients to see how the current literature sees their status in a vegan diet.
Macronutrients:
Vegan children of all ages have a body weight and body height similar to their peers, although it tends to be slightly below. They are, on average, less overweight or obese. Their intake of carbohydrates and fiber is higher compared to omnivorous children and their intake of protein and fat is lower, although still within the normal range. The quality of the fat and carbohydrate intake is usually better for vegan children than for vegetarian and especially for omnivorous children. Overall, vegan children consume a similar amount of calories like omnivorous children but less added sugars.
The protein intake of vegan children is sufficient if a variety of plant-based foods (grains, legumes, soy) is part of the diet, and can be supported with soy-based products and meat analogues. However, there are concerns about the quality of the proteins, as one study of young children found relatively low levels of some essential amino acids (the building blocks of proteins) in circulation in the body.
The statements regarding marconutrient intake apply for all age groups. It is, however, recommended that infants up to 12 months of age should avoid food rich in fiber due to the high energy demands in their development and should rather be fed with a diet rich in fruits, vegetable juices, peeled beans, refined grains, and soy products.
Micronutrients (vitamins and minerals):
The critical micronutrients are vitamin B12, vitamin D, and calcium.
Vitamin B12 (cobalamin) is probably the most famous risk factor in a vegan (and actually also a vegetarian) diet, as it is only contained in animal food and, with limited bioavailability, in some algae and fungi. Supplementation for children and adults is highly recommended because vegan sources do not provide the needed amount. Also, breastfeeding mothers need B12 supplements because a lack of B12 can lead to irreversible neurological damage in the infant.
Vitamin D is actually vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). They are fat-soluble and, like calcium, important for bone health. You probably know that the human body can synthesize them if it is exposed to enough sunlight, but this is not a reliable source in many parts of the world and depends on the season. A deficiency is likely independent of the diet and supplements are recommended for adults and children in many countries. Still, vitamin D is mostly found in animal-based food and the studies on vegan children often report vitamin D values below the reference. Thus, supplements or fortified drinks and food are especially recommended for a vegan diet, in particular for pregnant humans and infants until 18 months of age.
Calcium (Ca) is very important for bone health but only available in limited amounts in plant-based food. There are good sources (tofu, soy drinks, broccoli, kale, cabbage, which all have little oxalate, and some mineral water) and not-so-good-but-still-useful sources (nuts, dried beans, and spinach have calcium with limited bioavailability). Some studies report too little calcium in vegan children, some report acceptable amounts. It looks like a suitable choice of food sources is enough and supplements are not needed, but fortified foods and drinks (like some oat or soy drinks) can make the food selection easier.
Iron (Fe) has quite an interesting status in the human body, as it participates in many biological processes but can be damaging if too much is present (see, e.g., 10.3390/nu12061761 or here). Although plant-based food is a good source of iron, its bioavailability is less compared to iron in meat due to the presence of phytates or oxalates.2 However, some substances in fruits and vegetables (carotenes, retinol, ascorbic/citric/lactic/malic/tartaric acid) increase the bioavailability.3 Supplementation is recommended for vegans, in particular during pregnancy (for the mother, obviously) and breastfeeding (for the child). Otherwise, studies do not indicate an high risk of iron deficiency and find enough iron intake, but the ferritin levels4 in vegan children are typically on the lower side. This might indicate that the actual status of iron in the body is not so high. Thus, I would say that the data on iron is still inconclusive.
Zinc (Zn) is relevant for cell functioning and the immune system. Like iron and calcium, its bioavailability in plant-based food is less compared to animal-based food (due to the presence of phytates or oxalates), but again some substances in fruit and some food processing (e.g., fermentation and grinding) increase zinc absorption. None of the articles that I looked at identified zinc as a problem, although it was suggested to use zinc-fortified cereals for weaning. However, more data might be needed here.
Iodine (I) is, among other functions, needed for brain and bone development (via thyroid hormones). It is contained in sea fish, meat, eggs, and dairy, but most importantly in iodized table salt. The risk of iodine deficiency is not specific to a vegan diet but a general risk, and iodized table salt is the recommended form of intake.
n-3 fatty acids, or long-chain n-3 fatty acids, or omega-3 fatty acids, are polyunsaturated fatty acids. Three are relevant, which are abbreviated as ALA, EPA, and DHA. Those fatty acids are contained in flaxseeds, chia seeds, and walnut, canola (rapeseed) and soy oil, which should be preferred over peanut, corn, sunflower and olive oil. DHA was sometimes found to be present in too low amounts in vegan children, but also here more data would be good.
Vitamin B2 (riboflavin) is the basis of two molecules that do a lot of good stuff in the body, e.g. for your skin and hair. It was lacking, but this seems not to be specific to a vegan diet, even though dairy products are a good source. Plant-based sources exists (nuts, mushrooms, legumes, textured soy proteins) as well as fortified milk-alternatives.
Vitamin A (a group containing retinol, retinal, and beta-carotene) has many functions in the body but may be most famous for its relevance in vision. In one study on young children it was found that its status in the body was insufficient despite enough intake, although the authors mentioned that testing for the status of vitamin A is a bit tricky. Otherwise, I have not found much about a possible problem with vitamin A for vegan children.
Otherwise, it was found that vegan children have more folate, vitamin E, vitamin B1, vitamin C, and in some studies a low amount of (the good) HDL and (the bad) LDL cholesterol was found. As cholesterol is relevant for cell growth, low levels may or may not be a concern. Selenium was not studied in the articles that I read.
Summary
Most studies do not see a problem with a suitably-chosen vegan diet for children and there are indications of health benefits. However, vegan parents are typically well-informed and health-conscious, hence they do not reflect the average population. In general, more care needs to be taken regarding the diet than if and omnivorous diet is used, and regular checkups are necessary. The critical nutrients are vitamin B12 (supplements are recommended), vitamin D (supplements or fortified food are recommended), and calcium (a good choice of the diet and maybe also fortified foods and drinks are recommended). More information is still needed regarding iron, zinc, n-3 fatty acids, and maybe also iodine as well as vitamin A.
Long-term data on the effect of a vegan diet on children is still not available, so possible health benefits cannot yet be assessed. There are still many prejudices regarding a vegan diet in parts of the population and, unfortunately, also among some healthcare specialists. Hence, parents can have problems to get qualified support of they choose a vegan diet for their children. This will hopefully change soon, as those parents that do not get the support that they need from their pediatricians may then turn to other, less trustworthy sources of information.
So, overall it looks pretty good for this kind of diet and I’m looking forward to reading more about how the metabolism of vegan children differs from omnivorous children or how many vegan children start eating meat during puberty to annoy their parents. Unfortunately, however, I will almost certainly not survive until the day that a vegan from birth becomes the oldest person on the planet.
Literature
Nutrient status and growth in vegan children, 2021; 10.1016/j.nutres.2021.04.005
Review that gives a good overview about the current state of knowledge.
Nutrient Intake and Status of German Children and Adolescents Consuming Vegetarian, Vegan or Omnivore Diets: Results of the VeChi Youth Study, 2021; 10.3390/nu13051707
Large cross-sectional study about 6-18 years old humans in Germany. The intake and levels of macro- and micronutrients are assessed. Little problems with a vegan or vegetarian diet are found, at least in the way how the parents currently implement it (typically with supplements). Very relevant and informative.
Vegan diet in young children remodels metabolism and challenges the statuses of essential nutrients, 2021; 10.15252/emmm.202013492
Study about Finnish children (~3.5 years of age) that finds that a strict vegan diet leads to a different metabolism but it is difficult to say if this is also problems. Vitamin A and D status can be problematic.
Case report of nutritional rickets in an infant following a vegan diet, 2020; 10.1016/j.arcped.2020.03.008
The parents of an infant decided to feed it with a self-designed vegan diet (but with some fish oil). They also had the not-so-clever idea to ignore any check-ups from day 12 until the 12th month, when they became a bit worried about it not being able to get up alone anymore. Turns out it was a vitamin D (and calcium) deficiency. The child was temporarily separated from the family and given supplementation. The parents agreed to follow the procedures that were developed in the past to mitigate the risks of childhood and the child seems to have fully recovered.
Vegetarian and Vegan Weaning of the Infant: How Common and How Evidence-Based? A Population-Based Survey and Narrative Review, 2020; 10.3390/ijerph17134835
Italian study based on questionnaires and literature research to assess how well the transition from breastfeeding to feeding works for vegans and vegetarians. The authors say that the family pediatrician is often not seen as a good guide for alternative diets by the parents. This can be potentially risky for the infant, as the parents might ignore the advice of the pediatrician and/or might rely on false information (see the case report above).
Energy, Macronutrient Intake, and Anthropometrics of Vegetarian, Vegan, and Omnivorous Children (1–3 Years) in Germany (VeChi Diet Study), 2019; 10.3390/nu11040832
Large study on young children that analyses the intake of macronutrients and finds that there is no problem with a vegan or vegetarian diet. However, the actual status as well as the intake and status of micronutrients was not analyzed. This would be interesting, as measuring the intake itself may not be enough (see the Finnish study above).
Vegetarian diets in childhood and adolescence, 2019; 10.1186/s40348-019-0091-z
Position paper of the nutrition committee, German Society for Paediatric and Adolescent Medicine (DGKJ), that talks a bit about potential risks when restricting the dietary choices.
Developing a Food Exchange System for Meal Planning in Vegan Children and Adolescents, 2019; 10.3390/nu11010043
This article proposes a way of how to exchange animal-based product with plant-based products while still keeping a similar amount of nutrients. Very interesting, although focused on the intake. The practical recommendations in table 3 can be useful.
Vegetarian diets in children: a systematic review, 2017; 10.1007/s00394-017-1416-0
Meta-analysis of 24 publications about 16 studies from 1988-2013, finding that a vegetarian diet tends to be beneficial. However, it also notes that more data is needed and that the old studies are not so helpful due to recent changes in the dietary habit.
- Why should you rely on cultural knowledge? Because death is entirely natural, and the reason why we live a reasonably safe and comfortable life is because of our collective knowledge on how to avoid death. After all, your ancestors have survived long enough to have children, so their behavior has been successful for some reason and they, as parents, want to pass this knowledge it on to their children. And why should we rely on science? Because the modern scientific method (i.e., making assumptions and testing them) is a shortcut to test and to improve our cultural knowledge without getting killed. Of course you can choose homeopathy to treat cancer or deny your child the vaccines that would protect it from agonizing diseases; that is certainly more “natural”, but maybe not the best choice from an evolutionary point of view.
- They are even called “anti-nutrients”. However, just avoiding them might not be a good idea, they seem to also have some beneficial effects.
- BTW, milk as well as eggs decrease the bioavailability of iron.
- Ferritin is an iron-storing molecule in the body and acts as buffer to prevent iron deficiency or overload.
nice article !
Thanks!