Why Don't Regular Iron Pills Work for Me?

Ordinary iron tablets may simply "not work" in two major scenarios: they are not being absorbed at all, or you are using/losing more iron than you take.

Reasons Why It Happens

Gastrointestinal side effects lead to missed doses. Ferrous sulphate/fumarate is notorious for nausea, acidity, constipation, abdominal pain, or black stools. Skipping it in first several days will prevent recovery of Hb/ferritin level. According to Cleveland Clinic, constipation, cramping, and other digestive symptoms are common adverse reactions to oral iron.

Iron is taken together with antagonists. Tea, coffee, milk, calcium supplements, antacids, and proton-pump inhibitors like omeprazole/pantoprazole decrease its absorption. Mayo Clinic Health System recommends avoiding food rich in calcium, tea, and coffee along with iron due to poor absorption.

Formulation may not fit you. Ordinary iron tablets contain mostly conventional forms of iron as ferrous sulphate or ferrous fumarate. Chelon material of Tzana's claims that chelated form of ferrous bisglycinate provides higher bioavailability and lower risks of constipation and stomach irritation with 30 mg of iron + vitamin C.

There may be ongoing losses of blood. In men and post-menopausal women especially, iron deficiency should never be addressed blindly by iron tablets for several months before searching its cause. According to NICE, iron diagnostic trial should not be undertaken in men and post-menopausal women without excluding possible gastrointestinal bleeding sources.

It may be not an ordinary iron deficiency. Tiredness and decreased levels of Hb can also result from B12/folate deficiency, thyroid disease, chronic inflammation, renal insufficiency, thalassemia trait, or multiple deficiencies.

You may suffer from poor absorption of iron. Possible causes are gastritis, Helicobacter pylori infection, celiac disease, inflammatory bowel disease, bariatric surgery, chronic diarrhea, or prolonged usage of acid-suppressing medications.

What You Can Do

Find out if there is a failure indeed: perform CBC, Hb, MCV, ferritin, transferrin saturation/TIBC, CRP, plus B12, folate, and TSH test after 3-4 weeks of proper iron intake. Level of Hb usually starts rising in case of success; if it does not, the problem is probably caused by poor adherence, poor absorption, incorrect diagnosis, or ongoing loss of iron.

In order to maximize iron absorption, it is necessary to take it apart from tea/coffee/milk/calcium/antacids, with water or vitamin C preferably. If regular forms of iron upset your stomach, chelated form like ferrous bisglycinate can be easier to tolerate, but iron deficiency requires finding out the cause anyway.