Originally Answered: How could a vegan diet be safe and practical for infants and small children?
She didn't end up with rickets because she was vegan, she ended up with rickets because her parents didn't bother to see to her vitamin D intake. There's a big difference.
The American Dietitic Association and the Dietitians of Canada agree that a properly planned vegan diet is appropriate for ALL life stages, including pregnancy, lactation, infancy, childhood and adolescence.
It's the reponsibility of all parents to make sure that their children are getting the nutrition they need, regardless of the diet they've chosen for their families. A few isolated cases of malnutrition splashed all over the media should not constitute an indictment for a dietary plan that nutrition experts approve of. What the general public never hears about is the thousands of perfectly healthy vegan kids. I know four vegan kids personally ranging from 3-14; their parents are informed and responsible and the kids are happy, healthy and thriving.
I don't know all of the details of this particular case so I don't know if there were deficiencies beyond vitamin D, but that's all that was covered in the story. In that case, since she lived in Glasgow, which is too far north to get the necessary sunshine to form vitamin D most of the year, her parents could have added fortified foods or a supplement to her diet. Note that dairy products do NOT naturally have vitamin D. Rickets used to be a common problem. Vitamin D and calcium work best in conjunction and government officials needed a vehicle for getting sufficient vitamin D into children's diet, so they chose milk because it already had the calcium and most children drink it regularly. There's no reason, knowing those facts, that a vegan child drinking fortified plant milk would be any different than an omnivore child drinking fortified animal milk.