The vegan diet, although beneficial for adults in the prevention of metabolic diseases, raises questions about its benefits for a growing child : adequate caloric and protein intake, quality of essential amino acids, presence of essential fatty acids, inhibition of absorption of trace elements (including iodine, iron and zinc) and supply of various vitamins. Whereas vegan food is vitamin B12 deprived, the biggest challenge remains the vitamin B12 substitution in pregnant women, breastfeeding mothers and children at any age. Specific management by pediatricians using dietetic support and blood analyzes are required for children under vegan diet with respect of moral and ethical values related to this lifestyle choice.