An unexpected finding is the seemingly high prevalence of low sFt among women in the highest Hb category. There is no obvious reason why these sFt values should erroneously be low. It is conceivable that the women in the highest Hb category, in part, are not a healthy population. Their Hb may be elevated due to insufficient plasma volume expansion and their low sFt concentrations may demonstrate truly insufficient stores. We may have to expand our current thinking on ID and keep the
possibility open that even women with high Hb may be a