These points are interrelated. > Which means nothing to the people who don't have it So in the case of lactose intolerance, what's interesting, in fact, is th

These points are interrelated. > Which means nothing to the people who don't have it So in the case of lactose intolerance, what's interesting, in fact, is the environmental impact of the fact that the people in the Western world are largely fine with lactose. As the PBS NewsHour story about the causes and effects of China's meat consumption habits shows, Western habits are having a significant influence in the diets of the younger generation in developing countries. The effects of large-scale pollution of water resources is horrific, and competition for water resources is, after oil, the next source of conflict in the world. So yes, it will affect everyone. > Everyone knows this. That doesn't mean most First World people need supplements, because they don't. Sure, First World people don't need supplements, if they have a varied diet. In North America, that's a big if. There are cultural impediments to that varied diet, even for those with the means to afford it. But for many lower-income families, and especially those living in low-income neighborhoods, they experience the "food desert" problem. And they lack the same access to quality foods as more affluent people. That is a systemic issue related to how society (via government) deals with the problem. And the economics of the prices of foods is, in some part, related to the energy requirements which is related to the 90% energy loss up each level of the food chain. There is an environmental impact there. btw: I just threw in the names of Bittman and Pollan as representatives of the ideas of plant-based and natural diets. It's not like they invented the ideas; they're just the most recognizable cheerleaders for them at the moment.