Earlier quoted context omitted.
At the very least some animal product is necessary (e.g., dairy or eggs). See: http://www.nytimes.com/2007/05/21/opinion/21planck.html Vegetarians can go ahead and argue that vegans are too extreme while vegans fire back that vegetarians are just vegans who lack commitment.
I am vegan and have been for about a year and a half. Animal products are not necessary for a healthy diet. That goes for adults and infants. http://www.veganoutreach.org/enewsletter/20070523.html Crown Shakur did die because he parents didn't supply him with adequate nutrition, but there's no reason he couldn't have gotten what he needed on a vegan diet. Plenty of children are raised on a 100% vegan diet and thrive…
Citation? The only children I know [that I can recall] that are brought up in vegetarianism are noticeably "weedy". Shorter than average, low muscle tone, paler skin than their peers. That's completely anecdotal and a very small sample but it informs my demand to see your support for this claim.
Now it's probably quite possible to create a vegan diet with all required nutrients a child needs; but how practical is that and does it happen.