Timing of Food After Iron Supplements
You can eat a full meal 2 hours after taking iron supplements to maximize absorption while avoiding food-related interference. 1
Optimal Timing Strategy
The evidence strongly supports specific timing windows to optimize iron absorption:
Wait at least 2 hours after taking iron before eating to ensure maximum absorption, as food consumed within 2 hours after oral iron can reduce absorption by as much as 50%. 1
Ideally, take iron 1 hour before meals on an empty stomach in the morning for best results. 1, 2
Morning dosing is superior to afternoon or evening because serum hepcidin (which blocks iron absorption) increases during the day and reduces absorption of doses taken later. 1, 2
What to Avoid During the Waiting Period
During the 2-hour window after taking iron, avoid:
Coffee and tea - These are powerful inhibitors of iron absorption (coffee decreases absorption by 54%) and should not be consumed within 1 hour after taking iron. 3, 2
Calcium-containing foods or supplements - Calcium significantly reduces iron absorption and should be avoided during this window. 1, 3
Fiber-containing foods and whole grains - These contain phytates that bind iron and prevent absorption. 1, 4
Dairy products - Milk and other dairy reduce iron absorption due to calcium content. 4, 5
What You CAN Take With Iron
To enhance absorption, iron should be taken with:
Vitamin C (approximately 100-500 mg) - Take with orange juice or a vitamin C tablet to enhance absorption by 30%. 3, 4, 2
Plain water - If vitamin C or citrus juice is unavailable, take iron with a full glass of water. 5
Remain upright for 30-60 minutes after taking iron to reduce the risk of pill esophagitis. 5
Practical Dosing Schedule
The most effective regimen is:
Take one tablet (50-100 mg elemental iron) in the morning on an empty stomach with orange juice or 100 mg vitamin C. 1, 3
Wait 2 hours before eating breakfast or consuming coffee/tea. 1, 2
Consider alternate-day dosing (every other day) if daily dosing causes intolerable side effects, as this significantly increases fractional iron absorption while reducing gastrointestinal symptoms. 1, 3
Common Pitfalls to Avoid
Do not take iron multiple times daily - Doses of iron ≥60 mg stimulate hepcidin elevation that persists for 24 hours and blocks absorption of subsequent doses by 35-45%. 1, 3
Do not take iron with breakfast - Even with orange juice present, consuming iron with coffee and breakfast decreases absorption by 66%. 2
Do not take iron with antacids or proton pump inhibitors - These medications significantly impair iron absorption. 5