Timing of Iron Supplements
By Reed Mangels, PhD, RD
A Vegetarian Resource Group member contacted us with a question about when to take an iron supplement. Here’s what they said: “My health care provider recommended that I take a low-dose iron supplement once a day. I’m vegan and eat small meals and snacks throughout the day. When is a good time for me to take the iron supplement?”
And here’s our response:
Iron is best absorbed on an empty stomach, either about 1 hour before or 2 hours after meals so one idea would be to take your supplement right when you wake up and wait an hour or so to eat breakfast. If this isn’t feasible, you could take your supplement 2 hours after your last meal or snack of the day. Maybe taking it when you brush your teeth before going to bed, assuming you don’t have a snack right before bed, would work.
Although it’s ideal to take iron supplements on an empty stomach, some people get an upset stomach, nausea, or diarrhea if they don’t eat something along with their iron supplement. If that’s the case for you, try taking the supplement with a small meal or snack or immediately after a small meal or snack. You’ll absorb somewhat less iron but it’s likely that you’ll be getting more iron than if you didn’t take the supplement at all.
If you choose this option of taking your iron supplement with a small meal or snack, go for a meal or snack where you’re not drinking tea, herb tea, coffee, or calcium-fortified plant milk. All of these beverages can reduce iron absorption. Also, avoid foods high in phytate such as whole grains, dried beans, nuts, and seeds which can interfere with iron absorption. You might choose a snack of fruit, vegetables, and/or refined grains with your iron supplement.
If you use a calcium supplement, ideally you would take this at a different time than when you take an iron supplement.
Iron supplements may interfere with the absorption of some medications including levodopa, levothyroxine, penicillamine, tetracyclines, and bisphosphonates. Check with your health care provider about medications you are using and if they will be affected by supplemental iron.
To read more about iron sources for vegans see:
Latin American Vegan Foods High in Iron
The contents of this website and our other publications, including Vegetarian Journal and Vegan Journal, are not intended to provide personal medical advice. Medical advice should be obtained from a qualified health professional. We often depend on product and ingredient information from company statements. It is impossible to be 100% sure about a statement, info can change, people have different views, and mistakes can be made. Please use your best judgment about whether a product is suitable for you. To be sure, do further research or confirmation on your own.
