On one side, there are many people who say it's essentially safe or healthy; on the other people that say that a vegan diet for babies and infants requires constant supervision of a pediatrician.
What is the current scientific consensus on the risks and benefits of administering a vegan diet to the very young?
An example of the claim that it is harmful from the links:
Ed è a causa di un’alimentazione sbilanciata che in questi giorni è ricoverata all’ospedale Gaslini di Genova la piccola Chiara di nemmeno 3 anni, giunta in uno stato di salute talmente grave da richiedere subito la rianimazione.
I medici hanno collegato tutto questo alla dieta vegana che la bambina seguiva dalla nascita.
Baby Chiara, not even 3 years old, has been hospitalized for a few days because of an unbalanced diet. She was in such a bad state to require emergency reanimation. The physicians connected all this to the vegan diet that the child followed since birth
An example of the claim that it is healthy:
It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases