I believe your doctor is right to suggest an iron infusion because both your hemoglobin and ferritin are substantially below normal, and it would take too long for oral supplements to do the job.
Post Edited (MMMNAVY) : 3/11/2008 8:26:18 PM (GMT-6)
According to the October 14, 2006 issue of Gut (a medical journal), iron infusions are recommended when hemoglobin drops to between 10-12 at the same time that ferritin drops to below 20. More info from the same issue:
"When serum ferritin is less than 15 ug/l, iron stores are definitely depleted. When iron stores are above 20 ug/l, there is iron in the stores but it may be insufficient to meet the proliferating progenitors of red cells..."