I have benefited greatly from eating organ meat, most importantly beef liver. I have had issues with adrenal fatigue, am recovering from chronic illness and found that vitamin/mineral supplements were never enough to keep my nutrient levels up and give me energy. Since eating liver, kidney, heart, bone marrow and oysters, I have noticed a huge increase in energy. I guess most normal people might not notice these effects but if you're sick and fatigued you probably would. I highly recommend it.
I can't say much about getting nutrients from plants as I never could eat enough to make any difference in my health or energy.
As for numbers, my B12, folate and iron have been on and off low for years. I took supplements which brought my levels to low-normal in each range. Now without supplements and eating organ meats, I'm sitting in the high-normal range.