You can read the article in CBS NEWS by yourself, but it basically says that the parents of baby Lucas whom ran a natural food store in the town of Beveren in Belgium that they were attempting to raise their son on an alternative diet that included quinoa milk. Doctors had warned that such a diet is generally unsuitable for such young children. The seven-month-old baby died weighing just 9lbs after his parents fed him an alternative gluten-free, lactose-free diet.
http://www.cbsnews.com/news/belgian-convicts-alternative-diet-parents-in-death-of-baby-lucas/
I think the parents are strong animal lovers, but they didn't know that their dear baby needed something they themselves were against using. The mother could have breastfed their son :(