The Effects of Iron Deficiency on Concentration, Cognitive and School Performance

There was actually a couple of studies that look at concentration, cognition and school performance in college age females. Those who received iron did slightly better, although not statistically different than those who didn't receive iron. The symptom relief is much faster with IV iron, but it's pretty quick with oral iron. Most people don't tolerate it well. And if you're sick, then it doesn't work. So what are the indications for IV iron? What would you say that they are? I live human.