Nutritional status of Finnish vegan children is adequate
Recently, a Finnish study on nutrient intake and nutritional status of six vegan children (published in EMBO Molecular Medicine January 20th 2021), and the following overstatements and misrepresentations in the Finnish media, have raised concern in vegan families. In this expert bulletin we analyze the results of the study in more detail and answer the most common questions.
In addition to six vegan participants, 10 vegetarians and 24 omnivores participated in the study. Two of the vegans were siblings. All participants were children attending Finnish daycare. The median age was 3.5 years.
Height was normal in all vegan children. Two omnivores and two vegetarians were short for their age. One omnivore and one vegan were considerably overweight. All other vegans were of normal weight. Among the vegetarians and omnivores were a couple of overweight children. However, there were no significant differences in growth, height and weight between the groups.
Nutrient intake refers to nutrients from food and dietary supplements. Nutrient concentrations refer to values measured by laboratory tests.
In vegan children, the intake of all vitamins and minerals as well as macronutrients studied was adequate in relation to the Finnish Nutrition Recommendations (THL 2019). Essential amino acid intake was not investigated in this study.
Good nutrient intake and the use of dietary supplements in accordance with the Finnish nutrition recommendations indicates that Finnish vegan families and the centralized menu planning of Helsinki municipal daycares carefully follow the nutrition recommendations. Finnish vegan caregivers are usually well acquainted with nutrition issues (Kaipiainen 2005). Through the Finnish child health clinic system, they also have the option to meet a registered dietitian and doctor, if necessary.
Energy intake in vegan children was adequate, and there was no difference between groups. Macronutrient intake in vegans was also as recommended: carbohydrates accounted for 49.2%, fat for 32.6%, and proteins for 13.5% of total daily energy intake. Total fat intake deviated from the recommendations in two omnivores and one vegetarian.
A difference in fat quality was observed between vegans and omnivores. Saturated fatty acid intake was below the recommended maximum of 10% of total daily energy intake in all vegans. By contrast, it was exceeded by most omnivores and three vegetarians. Intake of monounsaturated fatty acids were in line with recommendations, for both vegans and vegetarians. Intake of polyunsaturated fatty acids were below the recommended level in some omnivores.
Essential fatty acids
Intake of two essential fatty acids, alpha-linolenic acid and linoleic acid, was abundant in vegan children. In contrast, intake of the long-chain docosahexaenoic acid (DHA) was absent in vegan children, as expected. The long-chain fatty acid eicosapentaenoic acid (EPA) and DHA are not obtained from vegan food sources, other than microalgae-based omega-3 supplements and in small amounts from some seaweeds.
DHA is not an essential fatty acid because the body converts it from alpha-linolenic acid. However, in several studies, as in this one, DHA levels in vegans have been significantly lower than in omnivores. Concentrations may also be low in non-fish eaters, who otherwise follow a mixed or vegetarian diet, as DHA fatty acids are obtained from fish and seafood. The clinical significance of lower DHA levels in vegans is unclear. It is not known whether low concentrations are due to ineffectiveness in the elongation of fatty acids to DHA, or whether high concentrations only indicate fish eating. For safety reasons, the Finnish Vegan Association recommends a supplement of 200 mg/day of DHA for pregnant and lactating vegans. The Finnish Nutrition Recommendations also recommend consuming 200 mg of DHA daily, during pregnancy and lactation. The authors commented that low DHA levels combined with low retinol levels may affect vision. However, a review examining the DHA status of vegans and vegetarians found no adverse effects of low DHA on vision, cognition or health (Sanders 2009). Retinol levels were not studied.
The cholesterol intake was significantly higher in omnivores than in vegans or vegetarians. Measured blood cholesterol levels were lower in vegans than in omnivores and vegetarians, which was expected. Total, LDL, and HDL cholesterol levels were normal in all vegans. In children, a total cholesterol level below 4.0 mmol/l is considered normal. It was exceeded by half of the vegetarians and most omnivores. Two omnivore children exceeded the upper limit for adults (<5.0 mmol/l).
LDL cholesterol was normal (<3.0 mmol/l) in vegans and vegetarians. Among omnivores, a few concentrations above the upper reference value (<3.0 mmol/l) were observed. HDL cholesterol levels were normal in all children.
Cholesterol is a non-essential nutrient. It can be sufficiently synthesized in each cell of the body, thus dietary cholesterol is not required. Maintaining blood cholesterol levels within the recommended range is beneficial for cardiovascular health.
The cholesterol levels of the vegan children were normal, but can too low cholesterol levels be a disadvantage? The authors refer to its possible link to increased stroke risk, based on one study in adults (Tong et al. 2019). However, the association of high cholesterol with an increased risk of stroke is much more significant and well-established. Genetically low LDL levels appear to be associated with a risk of intracerebral hemorrhage (Falcone et al. 2020), but with statin medication reduced LDL cholesterol levels, for example, did not increase the risk (Hackman et al. 2011). Instead, decreasing LDL cholesterol by 1 mmol/l decreases overall mortality by 10% and coronary heart disease mortality by 20% (Baigent et al. 2010).
Protein and essential amino acids
The normal growth of vegan children indicates adequate protein and amino acid intake. Whether there are any clinical significances in the differences observed in essential amino acid levels between vegans and omnivores remained unclear. It would be interesting to know whether the essential amino acid intakes or levels in vegans were normal, but the information was unfortunately not reported in the article or its supplements. An omnivorous diet easily provides more protein than recommended, as was the case for two omnivore children.
Vitamin A deficiency based on vitamin A status was not found in children on a vegan or vegetarian diet. However, a deficiency (concentration <0.5 nmol/l) was observed in one omnivore. Three of the omnivores had a vitamin A supplement.
In addition, vitamin A status was examined based on the levels of retinol binding protein (RBP) and transthyretin. RBP is an indirect measurement of the amount of active form of vitamin A (retinol). The authors commented on the suitability of RBP levels for studying vitamin A status at the individual level and found retinol levels to be a more reliable measure. However, retinol was not studied. Based on the RBP levels, one omnivore, one vegetarian and one vegan were below the reference value for a deficiency. Based on the RBP measurement, concentrations of the other vegan children were below the reference values considered sufficient, but some of the concentrations of vegetarian and omnivores were also below the sufficiency levels. The difference between vegans and omnivores was significant. The researchers commented that using RBP levels on an individual level as a sign of vitamin A status has some pitfalls.
Comments of the three Referees who peer reviewed the study can be found here. In their comments, one of them criticized the choice of RBP for measuring vitamin A status instead of serum retinol, as recommended by WHO. The Referee also notes that the study in question does not provide enough evidence to support the assertion that vitamin A or D status in vegan children is insufficient.
Transthyretin is a protein that carries retinol and thyroid hormone. Its concentration was normal in the vegan children, although lower than in omnivores.
Although the intake of vitamin A in retinol equivalents in vegans was in line with the recommendations, and equal to intake in other groups, its concentrations were lower. This may be due, among other things, to the fact that the conversion of beta-carotene to retinol depends on the vitamin A needs, as well as to the increased importance of hereditary when retinol is not obtained directly from the diet (Tang 2010, Hendrickson et al. 2012). According to the authors, the absorption appeared normal.
The reasons for the differences in vitamin A status and RBP levels should be further investigated to find out if vegan children are at real risk of vitamin A deficiency and, if so, how vitamin A status in vegan children can be improved. Vitamin A levels should be determined using a commonly used measurement method, in other words, by measuring serum retinol levels.
To our knowledge, retinol levels of adult vegans have been studied in one study. Serum retinol status was significantly lower in the vegan groups as compared to the omnivore group. However, the mean retinol levels in all groups were adequate and beta-carotene levels were higher in the vegan group (Schüpbach et al. 2017).
Beta-carotene levels measured in two other studies have been adequate as well (Waldmann et al. 2005, Elorinne et al. 2016). VItamin A intake has been adequate in most studies (Larsson and Johansson 2002, Waldmann et al. 2005, Sobiecki et al 2016, Elorinne et. al. 2016, Rehn 2019), but it was below the recommended in one danish study (Kristensen et al. 2015).
Vitamin D deficiency (concentration <50 nmol/l) was not found in vegan children or children on other diets. Concentrations in vegans were lower compared to those following an omnivorous diet, but still above 50 nmol/l, which is a sufficient concentration according to the Finnish recommendations. According to some experts, the optimal vitamin D concentration should be above 75 nmol/l. However, the total intake of vitamin D was the same in vegans as in omnivores (18.2 µg/day). The authors thought the difference was due to vitamin D from vegan food being ergocalciferol (D2). For example, vitamin D obtained from plant based milk alternatives is D2, while in cow’s milk the vitamin is cholecalciferol (D3). Vitamin D2 is notoriously inferior in maintaining blood vitamin D levels (Tripkovic et al. 2012). At the time of the study (2017), there was a transition period, when many D2-containing supplements on the Finnish market were replaced by a lichen-derived D3. This could also explain why concentrations were low although measured in summer. Concentrations should be further investigated now that the availability and popularity of vegan vitamin D3 has considerably increased, preferably in the early spring when vitamin D levels are typically at their lowest. The findings also raise a question whether the recommended vitamin D supplement (10 µg/day) for young children is sufficient when vitamin D obtained from food is exclusively D2?
The intake of all vitamins was as recommended in the vegan groups. Vitamin B12, which is lacking in non-fortified vegan food, was also taken care of and its serum levels were adequate. Folate was abundant in food consumed by vegan children and, correspondingly, they had the highest concentrations, some above reference values. However, folate is a water-soluble vitamin that does not accumulate in a harmful way to the body. Insufficient intake of folate has been a persistent problem for Finns (FinRavinto 2017 survey, Valsta et al. 2018). There is no established upper limit for safe intake, in contrast to synthetic folic acid (EFSA 2008), which was not exceeded in any child. The authors commented on the potential disadvantages of high folate status along with poor vitamin B12 status, although this study found that all vegan children had adequate vitamin B12 status.
Intake of minerals (including calcium, iron, zinc, iodine) in vegans was in line with the recommendations and did not differ significantly from the intake of the other groups, except for iron and zinc, which were significantly higher in vegans. In addition, the status of zinc, iron, and iodine was studied and no differences were observed between children following different diets. Low hemoglobin and ferritin levels were present in all diet groups. Sodium intake was excessive in all diets and no difference was observed between groups. It would be beneficial to reduce children’s salt intake.
Further information is needed on following topics
Although the research is reliable and carefully conducted, it also has its flaws. The sample of six children is small, although the results for vegans were exceptionally consistent. We acknowledge that the authors had set goals for a bigger sample. We were hoping for more info on the following:
- Measuring serum vitamin A levels
- The form of vitamin D supplementation used by vegan children and, in the case of possible D3 supplements, information on the duration of supplementation (lichen-based D3 preparations suitable for children entered the Finnish market around the 2017 sampling year, although it was introduced in the popular plant based multivitamin Veg1 in august 2016.)
- Authors’ assessment of the adequacy of DHA levels in vegans and the need for possible supplementation
- Information on children’s EPA levels and assessment of adequacy
- Information on intake and status of essential amino acids
What is known from previous studies?
Quite a few studies on vegan children have been published so far. In the UK and the US, vegan children have been studied in the late 1980s and 1990s in two follow-up studies. In these studies, vegan children were born at normal weight and grew and developed normally, but were slightly lighter and shorter than their omnivorous peers. The nutrient intake in these studies has been largely adequate, with the exception of vitamin D, which has been low in all diets, including omnivorous. Vitamin B12 intake has been adequate. Iron and calcium intake was below the recommended level in some groups of children. Vitamin A intake has been abundant, but its serum levels have not been studied. (Fulton et al. 1980, Sanders and Purves 1981, Sanders 1988, O’Connell et al. 1989, Sanders 1992)
In 2019, the results of an extensive VeVhi Diet Study were published in Germany. The study included 430 children from age 1 to 3 years, 139 of whom were vegans. The study looked at growth and intake of energy and macronutrients, i.e. carbohydrates, fat and protein. No differences in energy intake and growth were observed between groups. The macronutrient intake of vegans was as recommended. They had higher carbohydrate and fiber intake than others. Similarly, they received less sugar than omnivores. The proportion of protein and fat increased with the transition from vegan children to vegetarians and further to omnivores (Weber et al. 2019).
At times scientific papers publish case reports of children on vegan or other vegetarian diets diagnosed with a nutrient deficiency. These case reports serve as warning examples, for example, of the serious consequences of a failure to supplement with vitamin B12 or vitamin D. However, no generalizations can be made from case studies because, as other studies on vegan children show, the necessary dietary supplements are well taken care of.
Our advice for vegan caregivers
- We do not recommend vitamin A supplements, as those are not recommended by Finnish pediatricians or nutrition recommendations. However, it is good to pay attention to the intake of vitamin A from the diet. Good sources of vitamin A, such as orange and green leafy vegetables (e.g., carrot, sweet potato, pumpkin, bell pepper, spinach, kale) should be provided daily. Cooking improves the utilization of beta-carotene. Processed tomato products and fruits like apricot, peach, mango and papaya are also good sources. In addition to these, vitamin A is obtained throughout the day from several smaller sources. Any fat ingested as a part of meals (oils, margarine, avocado, nuts, seeds) enhances the absorption of fat-soluble vitamins A and D. Some margarines are also fortified with vitamins A and D.
- Use vegan vitamin D3 as a vitamin D supplement
- Provide a plant based milk alternative with added folic acid only in moderation, as young children may exceed the safe level of folic acid intake more easily than adults
- Make sure every meal has a source of protein: whole grains, legumes, seeds, nuts. Contribute to protein diversity
Food at daycare
The nutritional adequacy of food in Helsinki municipal daycare has been discussed among caregivers of vegan children. This has been elucidated in more detail in a master thesis related to this study, according to which nutrient intakes in vegans were in line with recommended values and often better than in omnivores (Rehn 2019).
Although the vegan protein intake from daycare food (12 % of total daily energy intake) observed in the Master´s thesis reached the quantitative recommendations (10-20 % of total daily energy intake), it was significantly lower than in omnivores (19 % of total daily energy intake). The difference is explained by the menu of the vegans, which raises concerns about the versatility of the amino acid composition of the meals: in breakfasts and snacks, the protein source is almost invariably cereal. Some snacks have no source of protein at all. When bread is served, the protein-rich bread topping offered to omnivores is omitted from the vegan portion. Replacing it, for example, with a slice of tofu would diversify the intake of essential amino acids of vegan children in daycare and increase overall protein intake. According to the menu, soy drink should be served with the meals, but in practice it is oat drink in several daycares. The amino acid composition and protein content of soy drink would be a welcome addition to meals enjoyed by vegan children in daycare.
Main meals should have 1/3 of the portion of legume-based plant protein. When using a processed high-protein product such as tofu, a slightly smaller amount is enough. When planning protein content in menus, it is a good idea to aim for a 15 % of total daily energy intake, and use a variety of plant proteins, for breakfast and snacks too.
We call on the media to take responsibility in nutrition communication, both in headlines and in the content of stories. Some news spread disinformation about the results of the study, which has caused confrontation, hate speech against vegan families, and unnecessary concern for vegan caregivers.
The number of vegan children who participated in the study was small, and therefore conclusions should be drawn with caution. In summary, the overall nutritional status of these six vegan children was adequate, and caregivers of vegan children have no reason to worry. The children had grown normally and there were no statistical differences in height or BMI between the children. The intake of energy as well as all nutrients was in line with the recommendations. No nutrient deficiencies were found in vegan children. The findings of the study were largely consistent with previous studies of vegan children and adults. Although some measurements showed differences with other children, it does not automatically mean that there is something worrying. The study provided more indications for future research. As the authors point out, more long-term follow-up studies on vegan children are needed.
We would like to thank the research team for their valuable work and all the families who participated in the research. As the vegan diet becomes more widespread with increasing climate, environmental, animal rights and health awareness, we need more evidence-based information on how to plan safe and healthy vegan diets for all age groups. This study, too, is playing its part in improving the understanding of the strengths and areas for development of a recommendation based vegan diet.
Charlotta Hyttinen, M.Sc. (Nutrition Science)
Johanna Kaipiainen, M.Sc., registered dietitian
Evy Peltola, B.Sc. (Nutrition Science)
You can contact us at: [email protected]