OK, since this ISN'T on the Veg*n board, I'm going to weigh in with my completely unpopular opinion. Bear in mind that what I post here is based entirely on anecdotal evidence rather than published studies (I've looked, but haven't found enough of them that didn't have an obviously pro-dairy-industry slant).
I've known a LOT of vegan children. I was raised by hippies, first of all, and then I ran a veg*n restaurant that had a really "family" clientele including lots of vegans. I've worked on organic farms alongside vegan families. I've been doing this for a long time. I've also been a private vegan chef, and studied a fair amount of nutrition. FWIW, I was ranting about processed soy several years ago and everyone told me I was CRAZY, soy was BY DEFINITION nutritious and healthy. I'm so glad there's a more reasoned view on that now.
Some more caveats here: I think veganism is the ethically ideal way to eat. I was raised Buddhist. I try to live as close to that ideal as I can. I do NOT scoff at veganism. I love and applaud people who raise their children with the ethical structure that veganism implies.
In my experience, I think it is difficult to the point of being nearly impossible to raise children with a nutritionally adequate vegan diet. (Here's where the flamethrowers start to get charged up, I'm sure.) Yes, I know some people can make a full-time job of it with supplements and perfect nutritional balance and can achieve near-adequacy. However, this is assuming a Herculean level of planning and a basically-healthy-in-all-other-ways child. Most parents do not have either.
When I ran the restaurant, it was an ongoing topic of conversation among the (almost entirely vegetarian) staff, several of whom decided they would not raise their children vegan given what they'd seen. It was scary. You could pick the vegan children out at a glance. They were shorter. They were spindly. They clutched asthma inhalers or had tremors. They were, for want of a better word, sickly. I stopped guessing ages, because I would be so wildly off with vegan kids "He's so cute, is he two?" "Actually, he's five."
I have never--not once--met a vegan child who did not have health problems, or who was not VISIBLY more unhealthy than his/her peers.
I'm assuming they exist, because parents on internet message boards are always telling me that their child is completely healthy, and is vegan. And I will not call such parents liars. But I have met many, many more vegan and vegetarian children than the average person, and based on my observations I do not consider strict veganism to be an appropriate diet for a child.
Sometimes a do see a normal-looking kid, and the parents will claim to be vegan. And this will make me very happy, as I want veganism to be healthy for children! Inevitably, it comes out that the family is vegan but the child was given raw milk until the age of eight, or the child is given fresh fish caught by the family in a stream, or the mother believes children should be able to eat eggs. SOME kind of animal protein is sneaking its way in there.
I really wish this weren't what I had observed. And hey--if you're in NYC and want to show me otherwise, please do! I'd love to see if I could transition my children to veganism. But I can't--won't--do so until I see something different than what I've seen so far.
So yes, I think this article is dealing with reality. If debate on this topic is not allowed, then this thread should be moved to the veg*n board. As I said, I would never post this there--I would consider it rude to invade veg*n space with debate. However, I do think this needed to be said.