Iron

A mineral the body needs to make hemoglobin and myoglobin, the proteins that carry and supply oxygen to the body's tissues.

Supplement

What it is

Iron is a mineral the body needs for growth and development. The body uses iron to make hemoglobin, a protein in red blood cells that carries oxygen from the lungs to the rest of the body, and myoglobin, a protein that supplies oxygen to muscles. Iron in supplements is often in the form of ferrous sulfate, ferrous gluconate, ferric citrate, or ferric sulfate. Iron-containing supplements carry a required label warning about the risk of fatal poisoning in young children who take an overdose.

Food and timing considerations

The body absorbs iron from plant sources better when it's eaten with meat, poultry, seafood, and foods containing vitamin C. Calcium may interfere with iron absorption; taking calcium and iron supplements at different times of day may help prevent this.

Known interaction categories

  • Insufficient evidence
  • Monitor
  • Use caution

Published interaction pages on this site

Sources

Last reviewed 2026-08-22

Medical information disclaimer: this information is general and educational. It does not diagnose conditions, prescribe treatment, or determine whether a combination is safe for you personally. Follow your prescription label and ask a pharmacist or clinician before starting, stopping, or combining products. Full disclaimer.