Iron, the foundation
Iron directly rebuilds the body's stores. Plain ferrous salts are proven and inexpensive but can upset the stomach, while chelated bisglycinate and microencapsulated forms are gentler at similar effectiveness, which helps people actually finish the course.
Cofactors for absorption and red blood cells
Vitamin C sharply increases iron absorption from plant and supplement sources. B12 and folate are needed alongside iron to build healthy red blood cells, and copper supports normal iron metabolism.
Frequently Asked Questions
What is the best iron supplement?
For most people, a gentle, well-absorbed form like ferrous bisglycinate or a microencapsulated iron causes far less nausea and constipation than plain ferrous sulfate, which improves the odds you finish the course. Take it with vitamin C and away from coffee, tea, and calcium. The right elemental dose depends on your blood results, so test first.
Should I get tested before taking iron?
Yes. Ferritin, your iron storage marker, is the key test, and you should not take high-dose iron without confirming you are low. About 1 in 200 people carries a gene for iron overload, where extra iron damages the liver and other organs. Test ferritin first, then retest after a few months to confirm levels are rising appropriately.
Why does iron upset my stomach, and what helps?
The nausea, cramping, and constipation come mostly from unabsorbed iron irritating the gut, and they are worst with high-dose ferrous sulfate. Gentler options include ferrous bisglycinate, sucrosomial iron, and microencapsulated forms, lower daily doses, and alternate-day dosing, which research suggests can absorb as well with fewer side effects.
Should I take vitamin C with iron?
It helps, especially for non-heme iron from plants and supplements. Vitamin C keeps iron in the form that is most easily absorbed, so taking iron with a vitamin C source or supplement can meaningfully increase uptake. At the same time, separate iron from coffee, tea, dairy, and calcium supplements, which all blunt absorption.
How long does it take to restore iron levels?
Hemoglobin usually starts improving within a few weeks, but rebuilding ferritin stores takes longer, often 3 to 6 months of consistent supplementation. Keep going until your doctor confirms stores are replenished, not just until you feel better, or the deficiency tends to return. Retesting is the only way to know you are there.
When should I see a doctor about low iron?
If you have symptoms of anemia, heavy periods, black or bloody stools, or low iron that keeps returning despite supplements. Iron deficiency is a symptom, not a diagnosis, and in adults it sometimes signals blood loss from the gut that needs investigation. A doctor can find the cause and decide whether infusions are needed.