Iron needs increase to 27 milligrams (mgs) per day during pregnancy. (1) You need more iron during pregnancy because you are making more blood. Your blood volume increases about 50% over what it was before you got pregnant. (2)
It is usually difficult without careful food selection to get 27 mgs of iron per day. That is the main reason women are asked to take a prenatal vitamin. (3) You will notice that your prenatal vitamin directions may ask you to take it on an empty stomach. Taking it this way can increase the absorption of iron. If you don’t tolerate taking iron on an empty stomach, it is better to take it with food than not take your vitamin.
Be aware that taking iron with milk or other calcium-containing foods can interfere with the absorption of iron. (1) Also, be aware that taking iron with a Vitamin C containing food (like oranges, grapefruit or their juices) increases the absorption of iron. (4) Check with your healthcare provider if you have questions.
- Kleinman, RE, Greer FR, Pediatric Nutrition, 7th edition, Elk Grove Village, IL, American Academy of Pediatrics, 2014, pp 1357, 1372.
- Hytten, F, Blood volume changes in normal pregnancy, Clin Haematol 1985, Oct: 14(3):601.
- Position of Academy of Nutrition & Dietetics: Nutrition and Lifestyle for a Healthy Pregnancy Outcome, J Acad of Nutr & Dietetics, 2014; 114:1100.
- American College of Obstetrics & Gynecology: Nutrition During Pregnancy, April 2015, Available at, http://www.acog.org/Patients/FAQs/Nutrition-During-Pregnancy#iron Accessed June 10, 2015