RDA of Iron

My Supplement Has 100% of the RDA of Iron but My Iron is Still Low?

If you find yourself wondering why you are taking enough iron but you are still iron deficient, you may be taking the wrong type of iron. There are two types of iron. One is ionic iron which is manufactured in a laboratory from chemicals and the other is Heme Iron which is derived from bovine red blood cells. Heme Iron absorbs far better than does ionic iron. All Proferrin® products are Heme based iron supplements, ensuring that you are taking the only supplement you need to support healthy iron levels.

How does this relate to your iron supplement? The USDA publishes RDA’s based on the amount of a vitamin or mineral that you should ingest daily in order to maintain healthy levels. According to the Institutes of Medicine version the RDA of Iron includes a very important footnote (click on Elements Table .pdf file at bottom of page). That footnote says that the RDA “assumes” that you are getting 75% of that daily Iron intake amount from Heme Iron sources. So, if the iron in your supplement is ionic iron (virtually all of them are) the RDA really doesn’t mean anything relative to the iron supplement you are taking. Thus, it is very easy to be taking an iron supplement that supposedly meets the RDA, but still be low in iron, because not enough of the ionic iron is absorbing into the bloodstream to meet your body’s demand for iron. The only sure way to ingest enough absorbable iron is to take a Heme Iron supplement such as Proferrin®*. Furthermore you need to make sure that in your supplement the total number of milligrams of elemental iron in the form of Heme Iron is high enough to meet at least 75% of the RDA of Iron. There is only one supplement that contains 100% of its iron in the form of Heme Iron. That iron supplement is Proferrin®, and it contains a proprietary Heme Iron called Heme Iron Polypeptide. You will easily obtain the remaining 25% in the form of inorganic iron found in other foods such as enriched flours or grains used to make breads and cereals.[1]

Below is a table, which lists the recommended daily allowance of iron, with an adjoining column that showing the RDA recommendation when 75% of that intake comes from a Heme Iron source. The Institute of Medicine recommends that 75% of your iron intake comes from a Heme Iron source (e.g. lean meat, eggs, and seafood). Most iron supplements do not contain Heme Iron, which means if you are supplementing your iron, but not taking Proferrin®, you may not meet your recommended iron intake*.

GenderUSDA – RDA75% of RDA (Heme Iron)
Males8 – 11 mg. (age dependent)6 – 8.25 mg.
Females8 – 18 mg. (age dependent)6 – 13.5 mg.
Pregnancy27 mg.20.25 mg.

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


  1. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc : a Report of the Panel on Micronutrients. Washington, DC: National Academy Press; 2001.

PPI’s & Iron Deficiency

“Iron Deficient?

Have GERD or frequent Indigestion?”

Then you’re probably taking a Proton Pump Inhibitor (PPI) like Prilosec, Prevacid, Dexilent, Aciphex, or Protonix.  If so, you should be taking Proferrin® because PPI’s can and do impair absorption of non-heme iron. Your “typical” iron supplement won’t help if you’re taking a PPI,  according to Dr. Sharma (gastroenterologist).1

“These cases presented suggest that omeprazole-induced achlorhydria may impair the response to oral iron therapy”1  

“A hypochlorhydric state, therefore, would impair predominantly, the absorption of non-heme iron.”1   

If you are taking a PPI, Proferrin® heme iron is your best choice by far.

Why you should choose Proferrin® brand Heme Iron Polypeptide (HIP):

  • The ONLY Heme iron sourced from USDA edible red blood cells
  • Lowest cost per mg of Fe (as HIP) in the U.S. market
  • Multiple published “peer reviewed” medical studies using Proferrin® 2,3,4,5
  • Maintains healthy iron levels 3,4,5

Visit Proferrin.com to buy Proferrin® or to learn more about the Proferrin® brand and the science behind our products.


  1. Tempel, Mila et al. “Effects of omeprazole on iron absorption: preliminary study.” Turkish journal of haematology : official journal of Turkish Society of Haematology vol. 30,3 (2013): 307-10. doi:10.4274/tjh.2013.0042
  2. Seligman, PA, Moore, GM, Schleicher, RB. Clinical studies of hip: An oral heme-iron product. Nutrition Research. 2000;20(9):1279-1286. doi:10.1016/S0271-5317(00)00215-3.
  3. Nissenson, AR, Berns, JS, Sakiewicz, P, et al. Clinical evaluation of heme iron polypeptide: sustaining a response to rHuEPO in hemodialysis patients. American Journal of Kidney Diseases. 2003;42(2):325-330. doi:10.1016/S0272-6386(03)00658-9.
  4. Ndegwa, Sarah, and Raymond Banks. “Heme Iron Polypeptide (Proferrin®) versus Oral and Injectable Iron Products for the Treatment of Anemia.” Cadtha.ca, 28 Sept. 2007.
  5. Abdelazim IA, Abu-Faza M, Elbiaa AA, Othman HS, Alsharif DA, Elsawah WF. Heme iron polypeptide (proferrin®-ES) versus iron saccharate complex (ferrosac) for treatment of iron deficiency anemia during pregnancy. Acta Med Int 2017;4:56-61

Women and Iron

Iron Supplements for Women Experiencing Iron Deficiency

Iron deficiency is caused by an insufficient amount of iron in the blood. Inadequate dietary intake of iron can lead to iron deficiency, which can lead to iron deficiency anemia. iron deficiency anemia is a condition in which blood does not have an adequate number of healthy red blood cells, the cells that carry oxygen to the body’s tissues. Without enough iron in your blood, your body just can’t produce enough hemoglobin, the substance in red blood cells that enables them to carry oxygen throughout the body.

Proferrin® ES Heme Iron supplements for women can help maintain iron stores in females with symptoms of iron deficiency. [1] Your doctor can explain how Proferrin® ES works and will be able to determine if you would benefit from this popular Heme Iron supplement. Iron deficiency in women is more prevalent than in men for a variety of reasons including:

  • Blood loss—Women with heavy periods are especially susceptible to iron deficiency anemia because of the amount of blood lost each month. Bleeding from peptic ulcers, colon polyps, or hiatal hernias can also cause iron deficiency anemia. Over-the-counter pain relievers, taken excessively, can lead to gastrointestinal bleeding.
  • Insufficient iron in diet—If you do not consume enough foods rich in iron, you may become iron deficient. Iron-rich foods include meat, eggs and green leafy vegetables.
  • Problems with iron absorption—There are disorders that affect your body’s ability to absorb iron. The small intestine is charged with iron absorption, so if you suffer from an intestinal disorder or if part of your small intestine has been surgically removed, your ability to absorb Iron may be affected.
  • Pregnancy—Many pregnant women are diagnosed with iron deficiency anemia because the iron in their body must nourish the baby, too. [2]

What to do for Iron Deficiency in Women?

Iron supplements are the most commonly used method to maintain healthy iron levels in women. Proferrin® ES and Proferrin® Forte provide nutritional support for those who might be at risk of developing iron deficiency. Proferrin® brand products provide supplementation with lower side effects and are more easily absorbed than iron salts*.[3]

To order Proferrin® ES Oral Heme Iron supplements, visit our Buy Now page.

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


1. K. Suzukawa, et. al., A Study of preventive effects of a high-absorbable iron supplement on an anemia; Prevention of an anemic tendency of Ekiden runner caused by a summer camp. J Physic Fit Nutr Innunol, 1996. 6(1): p. 1-10.

2. Mayo Clinic online. Iron Deficiency Anemia.

3. Seligman, Paul A., et al. “Clinical Studies of Hip: An Oral Heme-Iron Product.” Nutrition Research, vol. 20, no. 9, 2000, pp. 1279–1286., doi:10.1016/s0271-5317(00)00215-3.

Athletes and Iron

Why Do Athletes Need Iron?

Adequate levels of iron in the blood are critical for athletes because of the role iron plays in binding oxygen, which must circulate throughout the lungs and muscles in the body.  Vigorous training stimulates an increase in the number of red blood cells and small blood vessels, increasing the physiological demand for iron.  As muscle mass grows, there is a corresponding increase in red blood cells and blood vessels, thereby increasing iron intake needs.[1]

Blood, Sweat & Tears

Athletes are at risk of iron depletion for several reasons. Initially, iron is lost through sweat.  The more an athlete sweats, the greater the risk of iron loss. Iron can also be lost through blood loss.  Strenuous exercise can affect the stomach and intestinal lining, causing gastrointestinal bleeding.  The habitual use of anti-inflammatory drugs by athletes throughout training can also cause gastrointestinal bleeding. Exercise-induced hematuria (blood in the urine) is also a concern after strenuous exercise.

Mechanical trauma, such as foot strike hemolysis, which is the repeated pounding of the feet on hard surfaces, can destroy red blood cells during activities such as running.  Athletes also experience blood loss due to injury, bloody nose, or even menstruation.  Additionally, endurance training can cause rhabdomyolysis, which further depeletes iron stores.


Meanwhile, iron intake through diet is often sub-optimal, due to food regimen during training.  Consuming enough of the right nutrients is rarely enough to meet the recommended daily allowance for iron. Demanding training schedules regularly prevent athletes from consuming regular meals.

Many athletes increase their carbohydrate intake prior to a race, unintentionally reducing their meat intake, further impacting iron levels. Coupled with a reliance on snack and convenience foods (even if they are healthy ones), athletes may not consume enough of the right nutrients to meet the recommended daily allowance for iron. Vegetarian and vegan athletes are at even greater risk for iron deficiency, particularly if they don’t substitute with sources rich in heme iron, the most readily absorbed form of iron.[2]


  1. Mairbäurl, Heimo. “Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells.” Frontiers in physiology vol. 4 332. 12 Nov. 2013, doi:10.3389/fphys.2013.00332
  2. Uzel, C, Conrad, ME. Absorption of heme iron. Seminars in Hematology. 1998;35(1):27-34.

Fighting Iron Deficiency during Pregnancy

Fighting Iron Deficiency During Pregnancy with Proferrin® ES and Forte Iron Supplements

Taking good care of your health and the health of your baby is crucial during pregnancy. One condition that affects some women is low iron during pregnancy; iron deficiency occurs when there is not enough iron in your blood. Without adequate iron supplementation, iron deficiency anemia can be the result.

Anemia is simply a lack of healthy red blood cells, the cells that circulate in the blood plasma and give blood its red color. Red blood cells obtain oxygen in the lungs and distribute it to all the cells in the body in a process called oxygenation. While the actual statistics regarding how many women suffer from iron deficiency anemia during pregnancy vary, it is quite common.

If your doctor tells you that you have low iron during pregnancy, he may have you take an iron supplement such as Proferrin® ES Iron Supplements or Proferrin® Forte, made with Heme Iron Polypeptide (HIP), a naturally-occurring source of iron.

What Causes Iron Deficiency During Pregnancy?

In order to keep you and your baby well nourished, the amount of blood in the body must increase by 50% during pregnancy [1]. As the mother’s body makes blood more quickly, the need for iron is often greater than the amount the expectant mother has stored in her body. The result is iron deficiency.

There are certain factors that will increase the likelihood that you will become iron deficient during pregnancy [2]:

  • Severe morning sickness with frequent vomiting
  • Insufficient intake of iron in your daily diet
  • Heavy menstrual flow prior to the pregnancy
  • Multiple pregnancies
  • Two or more successive pregnancies

Avoiding Iron Deficiency During Pregnancy

The good news is that you can take steps to reduce your chances of becoming iron deficient during pregnancy. Because iron deficiency during pregnancy is so very common, your blood will be checked during your first prenatal visit. Some doctors will repeat the test at about 28 weeks or whenever they are concerned you may be iron deficient [1]. Eating food high in iron and Vitamin C is the best way to keep your blood healthy during pregnancy:

  • Liver
  • Red meats
  • Eggs
  • Dried fruit
  • Green leafy vegetables, such as broccoli, kale, and swiss chard
  • Tofu
  • Pasta
  • Cereal
  • Oatmeal
  • Whole grains
  • Good sources of Vitamin C include oranges, strawberries, tomatoes and grapefruit.

Iron Supplementation During Pregnancy

Use of Heme Iron supplements in pregnant women is acceptable [3]. For iron deficiency in pregnancy, your doctor may recommend using Proferrin® ES in addition to your prenatal vitamins, especially during second and third trimesters. Proferrin® ES Heme Iron supplements for women can help keep iron stores from dropping during pregnancy [5]. An added benefit is that you will be less likely to experience the gastrointestinal distress that can occur with other iron supplements [4].

If you know your diet lacks iron or if you know you are iron deficient, please see our Buy Now page, or you can inquire about Proferrin® ES at your local pharmacy. Please consult your doctor before taking any supplements and to get specific serving instructions for Proferrin® ES or Proferrin® Forte.


  1. Utah Department of Health. Maternal and Infant Health Program. “Anemia During Pregnancy.”
  2. The Pregnancy Zone. “How to Prevent Anemia During Pregnancy?” [sic]www.thepregnancyzone.com
  3. Suzuki, S., et. al., Effect of Bioion 150 – Enriched Heme Iron Food – on Pregnant Woman and Anemic Women with Iron Deficiency, Obstetrics and Gynecology World, Volume 10, pg. 32-43.
  4. Ghaddar, abstract presented at NKF April 7, 2003, Dallas, TX.
  5. Abdelazim IA, Abu-Faza M, Elbiaa AA, Othman HS, Alsharif DA, Elsawah WF. Heme iron polypeptide (proferrin®-ES) versus iron saccharate complex (ferrosac) for treatment of iron deficiency anemia during pregnancy. Acta Med Int 2017;4:56-61