Accepted norms may be off because the control populations used to establish the numbers were not taking sufficient amounts to maintain peak cellular efficiency.
They established the RDA's by depriving a control group of nutrients until deficiency symptoms were induced, then measured how much of a nutrient was required to eliminate those symptoms. There have not been any studies done to determine how much of a nutrient is needed for a body to perform optimally. Without that kind of data, our only choice is to experiment on ourselves and try to figure out what we need individually.
If all the cars in the city have been missing a spark plug for over a century, it is considered normal to be puttering and sputtering around.