For best absorption, take iron supplements on an empty stomach along with 200 mg of vitamin C or an 8-ounce glass of orange juice. When taken together, vitamin C can enhance iron absorption by binding to non-heme iron and storing it in a form that’s more easily absorbed by your body [1
Additionally, avoid milk, yogurt, calcium, and antacids for at least two hours before taking your iron supplement as these can decrease the amount of iron that is absorbed. It’s also recommended to wait at least one hour after taking an iron supplement to consume caffeine and high-fiber foods (like whole grains and raw vegetables) as these can also hinder iron absorption.
Lastly, make sure to take your iron supplement as prescribed by your doctor or dietitian. Depending on the type and dose of iron you’re taking, they may recommend two or three smaller doses during the day to maximize absorption and minimize digestive upset.
If you experience stomach cramping, nausea, or diarrhea, taking your iron supplement with a small amount of food can help. If that is not enough, other forms of supplemental iron are available that might have fewer side effects.