Calcium and Iron
Calcium taken at the same time inhibits iron absorption; separate them by at least two hours.
Calcium
The primary structural mineral of bones and teeth.
Iron
Oxygen-carrying mineral critical for energy.
Combine with care
These can compete for absorption or interact; separate the timing or keep the doses balanced rather than taking large amounts together.
How to take them
Calcium
- Dose
- 500–1,000 mg per day from supplements, only to fill dietary gaps
- Timing
- Citrate any time; carbonate with food. Split doses above 500 mg.
Iron
- Dose
- Only when deficient; commonly 18–65 mg elemental iron
- Timing
- With vitamin C; away from calcium, coffee, and tea
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Frequently asked
Can you take Calcium and Iron together?
It's best to separate them across the day or balance the doses rather than taking large amounts at the same moment. Calcium taken at the same time inhibits iron absorption; separate them by at least two hours.
What's the best time to take Calcium and Iron?
Space them out. Calcium: Citrate any time; carbonate with food. Split doses above 500 mg.. Iron: With vitamin C; away from calcium, coffee, and tea.
How do Calcium and Iron interact?
Use with care: Can compete, deplete, or interact; time or balance them. Calcium taken at the same time inhibits iron absorption; separate them by at least two hours.
Related pairings
Calcium + Vitamin D3
Vitamin D3 is required to absorb dietary and supplemental calcium.
Boron + Calcium
Boron influences how the body retains and uses calcium, supporting bone mineralization.
Calcium + Vitamin K2
K2 activates the proteins that bind dietary calcium into the bone matrix.
Calcium + Magnesium
Compete for absorption at very high single doses; keep intake balanced rather than mega-dosing one.