Dietitian Elisa Rodriguez published a great interview with Jack Norris on One Green Planet last week. In talking about our book Vegan for Life, Jack noted that there are benefits to a “holistic” view of nutrition, but that his biggest contribution has most likely been in helping vegans understand that “micronutrients matter.” That’s because “being deficient in vitamin B12, calcium, vitamin D, iodine, omega-3s, iron, or zinc results in real consequences.”

It’s tempting to think that eating a variety of whole plant foods—the big picture or holistic approach—without attention to detail, is good enough for meeting nutrient needs. But that’s an approach based on philosophy, and there is no empirical evidence to back it up. And nutrition isn’t a philosophy; it’s a science. Which means that recommendations for vegans have to be based on scientifically-supported principles.

It’s true that humans managed to eat a healthy diet long before nutrients were discovered. But that was through a process of trial and error, until the available foods and practices that supported health became cultural norms.  We vegans don’t have that advantage because our “culture” is fairly new. We’re still working things out, and have no historical blueprint to guide us.  We can look to many of the world’s plant-based diets for some ideas, but since none of those diets are vegan, we’re still pretty much on our own. Fortunately, we do have nutrition science, which is a huge advantage.

Food is more than the sum of its parts, that’s for certain. But some of the parts—vitamins and minerals—are essential to life and health (not just good for you, but absolutely necessary) and they deserve to be singled out for consideration. We need to establish a few “rules” on how to meet needs for them as a way of creating a healthy vegan cultural diet.

Once in a while, I hear from vegans who are unhappy because they don’t think they should need to worry about whether they are absorbing enough iron in their diet or getting adequate calcium or eating enough legumes every day.  I understand that it’s annoying to have to bother about these things—but I’m not sure why they think it’s my fault. I really can’t take responsibility or blame for the nutritional requirements of humans. I can only look at what humans need based on the most current research, look at what plant foods provide, and then do my best to match them up.

And fortunately, it’s not that difficult to do so. The food guide on this site sums up the basics. It’s based on the information in Vegan for Life and is adapted from a food guide that was published in the Journal of the American Dietetic Association and that I created with Vesanto Melina (co-author of Becoming Vegan) and Reed Mangels (author of Simply Vegan and The Everything Vegan Pregnancy Book).

Yes, following it might feel a little more inconvenient than simply “eating a variety of whole plant foods.” But for most people, after paying attention for a little while, eating this way should become sort of second nature. And hopefully, someday we’ll have a world where this is just the way people eat—a part of a culture that no one thinks twice about.