Can frequent blood donation combined with a proton pump inhibitor cause iron deficiency?

I started giving blood in June, 2010 and gave once a quarter until March, 2011. I was also placed on Prevacid at Rx level in the 3rd quarter of 2010 and remained on it until March, 2011. My iron level dropped from 188 in Oct. 2009 to 16 in May, 2011. It is my understanding that frequent blood donation, especially for someone over 65, can lead to iron deficiency anemia. During that same period my hemoglobin dropped from 16.2 to 15 and, since stopping Prevacid, and taking iron supplements has increased to 15.8. Iron has only increased to 42 from16 after 6 weeks of SloFE tabs.