. I too read all the nutrition books - are you old enough to remember Adele Davis?
Anyway now that I have a better idea of what the gist of your question was, let me give you a better answer (although I think the short answer is good too.) Dr. McDougall's conclusions are backed by diligent scientific research. And most of the other MDs associated with VegSource or PCRM have come to similar conclusions. Dr. Campbell (China Study) talks about reductionism - don't get too hung up on the small details. The overall consensus is that a plant based, low fat diet is best and provides adequate nutrients.
Regarding protein - the best example Dr. McD gives is that human breast milk is 5% protein. How can a grown adult require more than an infant who is doubling his size in a matter of months? (Unless, of course, the adult wants to double in size too.
) That's simple for me to remember.
Regarding calcium - I can visualize the chart that Dr. McD shows: The greater the intake of protein, the greater the incidence of osteoporosis. And the cultures with the highest intake of calcium have the highest rates of osteoporosis. Again easy to remember. And makes you begin to question just exactly who thinks that calcium cures osteoporosis. (Oh yeah, the dairy industry.)
Now regarding micronutrients like zinc. If you eat some beans and whole grains you should be fine. (If I remember correctly from looking them up in the USDA nutrient tables.) Remember that the RDAs were effectively set by politicians and are based on people eating the SAD. So who says that they are correct? And wouldn't it make sense that the food we were intended to eat would have the correct proportion of these nutrients. The idea that our food will sustain us well if we eat it as close to how it grows as possible is another simple idea that keeps me grounded with all the other "reductionism" swirling around.
Vitamin D doesn't come from food but from the action of the sun on our skin. So if you live in a Northern climate, you might have a legitimate concern there. Dr. Esselstyn said at the Healthy Living Expo that he has his patients take Vit D supplements. (He's in Ohio, I think.) I'm in So Calif and I try to get out in the sun for a few minutes regularly. But I admit that since my dog died a few years ago, it's not as consistent as it once was. I try though. The soymilk I use is fortified with Vit D and Vit B12, so all-in-all, I just don't worry about it. I would recommend that you relax too. Plant-based, whole foods sure makes the equation easier.