How Much Iron Do I Need?
Quick Answer
Men need 8mg daily, women 18mg (8mg after menopause). But here's the catch: don't supplement iron unless you've tested and confirmed you're low. Unlike most vitamins, excess iron is harmful. Get your ferritin tested first.
Key Points
- Men 8mg, pre-menopausal women 18mg daily
- NEVER supplement without testing first
- Ferritin under 30 suggests deficiency
- Excess iron is harmful (unlike most vitamins)
- Vegetarians need 1.8x more (plant iron absorbs poorly)
Detailed Answer
DAILY REQUIREMENTS:
• Men: 8mg/day • Women (pre-menopause): 18mg/day • Women (post-menopause): 8mg/day • Pregnant women: 27mg/day • Vegetarians: 1.8x above amounts (plant iron absorbs worse)
WHY IRON IS DIFFERENT:
Unlike vitamin C or B vitamins, your body can't easily excrete excess iron. It accumulates. Too much iron causes oxidative damage. This is why you should NEVER take iron supplements without testing first.
WHAT TO TEST:
• Ferritin: Most useful. Under 30 = likely depleted. Under 50 = may cause fatigue. • Serum iron: Fluctuates, less useful alone • TIBC: High TIBC suggests deficiency • Hemoglobin: Late indicator of deficiency
WHO'S AT RISK FOR DEFICIENCY:
• Menstruating women (especially heavy periods) • Pregnant women • Vegetarians and vegans • Athletes (especially runners) • People with GI issues (poor absorption) • Regular blood donors
IF YOU NEED TO SUPPLEMENT:
• 18-27mg elemental iron is typical treatment dose • Take with vitamin C (improves absorption) • Take on empty stomach if tolerated • Avoid with calcium, coffee, tea (block absorption) • Bisglycinate form is gentler on stomach
Evidence Quality
Multiple high-quality studies support this
Key Sources:
- guidelineNIH Office of Dietary Supplements: Iron Fact Sheet
- reviewIron Deficiency in Athletes: Review
- studyIron Status Assessment: Laboratory Markers
Related Questions
Excess iron doesn't just pass through you. It accumulates and causes damage. Hemochromatosis (iron overload) affects 1 in 200 people. Many don't know they have it. Testing is cheap. Damage isn't.
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About this information: Our recommendations draw from peer-reviewed clinical trials, systematic reviews, and the same medical databases your doctor uses. These statements have not been evaluated by the FDA. Supplements are not intended to diagnose, treat, cure, or prevent any disease.
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