My Red Blood Cell count has been borderline low for a long time. When I was first tested when I started the abx protocol a couple years ago my RBC was just below normal range. I think it was about 3.76 (ref 3.8-5.10 Million/uL). My B12 and folate tested good. My ferritin was a little low but not dire. I started taking an iron/folate/B12 supplement. In a few months the ferritin went up to good levels but the RBC stayed borderline, just inside normal. For the 2 years I've continued taking the supplements but my RBC has remained low, hovering around 3.90, never really budging much.
Recently I read something in an article about anemia present with normal ferritin levels. It said something about copper being necessary for the blood cells to take in the iron and, no matter how much iron is present, if there is insufficient copper, one can still be anemic because the cells are unable to absorb the iron. I added a simple 100% RDA copper supplement to my stack of daily pills and, within just a couple months, my RBC has jumped to 4.14! Maybe not a huge increase, but the most it's moved in 2 years, and a significant increase for just a 2 month period. Since I've only been taking the copper a short time I'm hoping the RBC will continue to climb a bit more over the next few months.
One thing that can cause low copper is zinc since it interferes with copper absorption. I know a lot of us probably take lots of zinc for immune support. So if you're struggling with low RBC you might want to try a little copper. Not much, though! Be careful of copper toxicity (and it doesn't take a whole lot of copper to become toxic). Slow and steady is the safer way to go.