Intake of micronutrients and fatty acids of vegetarian, vegan, and omnivorous children

2021 Alpro Foundation Award for best scientific publication

Dr Stine Weder received the award for her PhD research on the nutritional adequacy of vegetarian and vegan diets for children.

“Children following vegan and vegetarian diets have good intakes of many micronutrients and essential fatty acids.”

Dr Stine Weder

Introduction

As vegetarian and vegan diets have become more popular, the question has arisen whether these diets are nutritionally adequate, particularly for children. The limited research in this field has mostly been cross-sectional and conducted with small sample sizes. Furthermore, the availability of vegetarian and vegan foods, such as meat and dairy alternatives has increased significantly in recent years.

Therefore, the team of Dr Markus Keller (Research Institute for Plant-Based Nutrition) in cooperation with PD Dr Ute Alexy (University of Bonn) conducted the Vegetarian and Vegan Children Study (VeChi Diet Study) aiming to compare the micronutrient intake and dietary fatty acid profile of children following vegetarian and vegan diets to that of omnivorous children.

Method

A total of 430 children aged 11 months to 4.3 years participated in the study (127 vegetarian, 139 vegan, and 164 omnivorous), primarily from urban areas in Germany with a mid-high socio-economic status. Dietary intake was assessed via a 3-day weighed food diary completed by the parents.

Energy and nutrient intakes as well as fatty acid profiles of the children's diet were assessed and compared to the harmonised Average Requirement (h-AR) as a measure of adequate intake. Further information about the children’s activity, current height and weight and other factors such as birth weight were also collected via an online questionnaire.

Key findings

Vegetarian and vegan children’s diets (including supplements and fortified foods) met the majority of the nutrient intake requirements. Dietary supplements were given to 97% of children on a vegan diet, over half of children on a vegetarian diet and 40% of omnivorous children.

When dietary supplements were excluded from the analysis:

• All children irrespective of diet type had on average very low intakes of vitamin D (<10% of h-AR) and iodine at 48-72% of h-AR.

• Vitamin B12: not surprisingly children on vegan diets had the lowest median vitamin B12 intakes (28% of h-AR), followed by those on a vegetarian diet which only just fell below h-AR (0.6mcg vs 0.7mcg h-AR). Only omnivorous children met and exceeded recommendations at median intakes of 1.5mcg/day.

• Calcium was below recommended intakes for children on a vegan diet (320mg/d, 82% h-AR), whilst those following a vegetarian or omnivore diet consumed adequate amounts.

• Vitamin B2 was just below h-AR for children following a vegan and vegetarian diet (86% and 92% of h-AR respectively). Whilst omnivore diets provided sufficient quantities.

Other significant differences between diet types were found – supplement intake was once again excluded from dietary analysis:

• Vegan children had the highest intakes of vitamins E, K, B1, B6, folate, and C and minerals potassium, magnesium, and iron

• Omnivorous children had the highest intakes of vitamins B2 and B12 and mineral calcium but also of saturated fat and cholesterol which exceeded the recommended daily intake.

• The fatty acid profile of the vegan children’s diet was most favourable (higher in PUFA/MUFA and lower in saturated fat and cholesterol).

• Long-chain fatty acids: the omnivore diets provided the highest intakes of the pro-inflammatory arachidonic acid, as well the highest intakes of the anti-inflammatory omega-3 EPA and DHA compared to the vegan and vegetarian groups. In contrast, the vegan diets provided the highest intake of the essential fatty acid alpha-linolenic acid (ALA) and both the vegan and vegetarian diets provided significantly greater quantities of linoleic acid (LA).

Discussion and recommendations

1. Vitamin and minerals

Vitamin D and iodine supplementation or fortification is essential for all infants and young children irrespective of diet type.

Vegetarian and vegan children’s diets should continue to be supplemented with vitamin B12. In addition, parents should ensure their children’s diets include several daily helpings of foods fortified or rich in vitamin B2 and calcium. Good plant sources of vitamin B2 include yeast extract, nutritional yeast, fortified breakfast cereals, fortified plant-based drinks and almonds. 3-4 daily servings of calcium rich foods should be encouraged such as fortified plant-based drinks and alternatives to yogurt, beans and pulses, tofu, nuts and seeds.

Iron intakes were greatest for children following a vegan diet with intakes 53% greater than omnivorous children. In the dietary recommendations of the European Food Safety Authority (EFSA), the h-AR for iron are doubled for those diets with a low absorption of iron from an unrefined diet such as vegan or vegetarian diets compared to omnivore diets to compensate for potentially lower bioavailability from plant sources. Without undertaking plasma ferritin and haemoglobin measures it is difficult to interpret the adequacy of iron intakes from this study.

2. Fatty acid profile

Omnivorous children's diets need to have a better balance of saturated fat and PUFA which could be achieved by including more plant-based foods.

Whether vegan and vegetarian diets need supplementation with EPA and DHA is under discussion, but vegan supplement variants based on microalgae are now available. What is important for plant-based diets is to improve the ALA to LA balance to help boost conversion to EPA and DHA in the body. ALA food sources include rapeseed oil, walnuts and chia, hemp and flax seeds.

Conclusion

All diet types need to be improved for infants and young children and vitamin D and iodine supplementation and/or fortification is essential to help meet requirements.

Vegan and vegetarian diets of infants and young children in this study contained most micronutrients in sufficient quantities to meet requirements. However, additional attention is needed to address insufficient intakes of vitamins B2 and B12 as well as calcium and improve the ALA to LA balance.

Omnivore diets also need attention to address high intakes of saturated fat and lower intakes of PUFA and MUFA alongside a higher intake of healthy plant-based foods.