A  60-year-old  woman  complained  of  weakness,  lethargy  and  easy  fatigability.  Investigation showed that she had iron deficiency anaemia (Hb. 8 g/dl). She was prescribed cap. ferrous fumarate 300 mg twice daily. She returned after one month with no improvement in symptoms. Her Hb. level  was  unchanged.  On  enquiry  she  revealed  that  she  felt  epigastric  distress  after  taking  the iron  capsules,  and  had  started  taking  antacid  tablets  along  with  the  capsules. What could be the possible reason for her failure to respond to the oral iron medication?
Gastric acid is required for the absorption of oral iron salts. Concurrent ingestion of antacid tablets could  have interfered with iron  absorption.  Hence,  the  anaemia  failed  to  improve.
Lower pH is required for absorption of oral iron salts
Higher pH is required for absorption of oral iron salt
Oral iron can not cross biomembranes in any form
Any of the above can be possible reason.