10 Natural Sources of Iron in a Daily Diet
Copyright 2012 - Kris Heeter, Ph.D. .
Iron comes from a number of different sources in your diet. It occurs naturally in many animal and plant foods, but it's also added to the processed foods we eat.
The addition of iron to fortify and enrich processed foods is a practice that has been done for decades to combat iron deficiencies, especially in children or adults with poor diets.
However, with proper diet and a focus on eating a well-rounded group of natural and whole foods, sufficient amounts of iron can be obtained without the need to supplement.
Heme and Non-heme Iron
Our dietary iron comes in two forms:
- Heme
- Non-heme
Heme iron comes from hemoglobin -- a protein in red blood cells that is responsible for delivering oxygen to cells. Heme iron is found in animal meat that originally contained hemoglobin, such as red meat, fish, and poultry.
Non-heme iron comes from plant foods. This form can also be added to food to enrich and fortify foods.
According to the National Institutes of Health, most dietary iron comes from plant sources but, it should be noted that it is absorbed better from heme sources compared to non-heme sources.
Best Natural Sources of Iron
You can obtain iron in your diet through a number of good natural sources. Here are ten notable ones:
1. Clams
2. Oysters
3. Organ meats (e.g. liver)
4. Soybeans
5. White beans
6. Kidney beans
7. Lentils
8. Spinach
9. Roasted pumpkin and squash seeds
10. Black strap molasses
Of this list, clams, oysters and organ meats have the highest levels of iron. Other foods like mussels, fish eggs, sesame seeds, sunflower seeds, and sun-dried tomatoes are also great sources.
This is not an exhaustive list -- for a more inclusive list, visit the National Institutes of Health: Iron Fact Sheet.
Symptoms of Low Iron Levels
If you have a deficiency in iron, it can lead to anemia -- resulting in a decrease in the amount of oxygen delivered to cells throughout your body.
Typically a blood test is used to confirm whether or not you have anemia. However, there are a number of iron deficiency symptoms that should be considered as potential warning signs:
- lack of energy or tiredness
- fatigue
- feeling weak
- feeling lightheaded
- headaches
- rapid heartbeat
- a drop in blood pressure when changing from sitting to standing
- finger nails that become thin and brittle
- a tongue that becomes white and may be sore, smooth and/or reddened
- decreased appetite
- shortness of breath during exercise
- brittle hair
- reduction in immunity and increased vulnerability to infection
- a weird desire to eat non-foods such as ice, paint or dirt (a condition called "Pica")
- disturbed sleep
- abdominal pain
When anemia goes unchecked, it results in fatigue and decreased immunity.
3 Ways to Increase Iron Absorption
If you are concerned about low iron levels, there are a couple of ways to increase your dietary absorption of this mineral:
- Eat a good source of vitamin C (e.g., citrus, tomatoes, broccoli or strawberries) with foods containing non-heme iron
- Eat foods that contain heme iron and non-heme iron together
- Cook foods in an iron pot, such as a cast iron skillet
Other factors that can affect your iron absorption:
- Large amounts of tea or coffee consumed with a meal will decrease iron absorption. The polyphenols in these drinks bind the iron and prevent absorption.
- A significant excess of high fiber in the diet can decrease absorption. It is the phytates (and phytic acid) in high fiber foods like bran that can inhibit absorption.
- High intake of calcium while eating foods with iron. Research suggests that taking an calcium supplement at a different time from an iron supplement will prevent a decrease in iron absorption.
Iron Toxicity or Poisoning Symptoms
While iron deficiencies are a concern and can be corrected with diet, too much iron in the body can also be a serious health problem.
Those eating iron-rich foods and taking iron supplements should be mindful of this and consult with a doctor as needed.
Early warning signs and symptoms of iron toxicity or poisoning include:
- Abdominal pain
- Nausea
- Vomiting
Those that suspect they may have ingested too much iron should have their blood checked and consult a doctor.
