Iron
Iron is an essential mineral for the proper functioning of the body. It is involved in many body processes, including oxygen use and transport, energy production, DNA synthesis, and immune function. Iron is contained in hemoglobin, a component of red blood cells, and myoglobin, which is found in the muscles.
Sources
The body can't produce iron, which means it must be obtained from food. The best sources of iron are:
- Blood sausage
- Liver
- Certain offal (e.g., kidneys, heart)
- Poultry
- Red meat
- Mollusks (e.g., oysters, clams, mussels, scallops)
- Whole grain or enriched cereal products
- Nuts and seeds
- Dark green vegetables
- Legumes
- Prune juice
- Blackstrap molasses
- Dried fruit
Contrary to popular belief, raw spinach contains very little iron; however, boiling spinach increases its iron content threefold.
People who are vegan or vegetarian are at greater risk of developing an iron deficiency. In addition to the fact that their diets exclude certain iron-rich foods, the form in which iron occurs in food affects its absorption. More specifically, the body absorbs iron from animal sources better than it absorbs the iron found in plants and eggs.
To improve the absorption of plant-based iron, it's recommended to include foods rich in vitamin C at every meal, such as citrus fruits, kiwis, strawberries, bell peppers, kale, broccoli, and other fruits and vegetables. It's also recommended not to drink tea with meals, as it decreases iron absorption. Coffee has the same effect, but to a lesser degree.
Below is a table to help you choose iron-rich foods.
Approximate iron content
| Food | Portion | Iron content |
|---|---|---|
| Clams, boiled or steamed | 5 large | 16.8 mg |
| Blood sausage | 75 g | 11 mg |
| Chicken liver, cooked | 75 g | 9.5 mg |
| Sesame seeds, whole | 60 mL | 5.7 mg |
| Mussels, boiled or steamed | 15 small | 5 mg |
| Lentils, boiled | 170 mL | 4.8 mg |
| Beef kidneys | 75 g | 4.4 mg |
| Oysters, raw | 75 g | 4.2 mg |
| Enriched cereal | 30 g | 4 mg |
| Food | Portion | Content |
|---|---|---|
| Red beans, boiled | 175 mL | 3.9 mg |
| Blackstrap molasses* | 15 mL | 3.8 mg |
| Spinach, boiled | 125 mL | 3.7 mg |
| Beef steak, cooked | 75 g | 3 mg |
| Plain tofu | 150 g | 2.2 mg |
| Cashews, dry roasted | 60 mL | 2 mg |
| Apricots, dried | 60 mL | 1.8 mg |
| Prune juice, ready-to-drink | 125 mL | 1.6 mg |
| Commercial whole wheat bread | 1 slice | 1.2 mg |
*Blackstrap molasses is different from the fancy molasses generally used for cooking. Blackstrap molasses has a darker hue and a more pronounced flavour. In addition to being slightly less sweet, it has certain nutritional benefits. It can be found in some grocery stores and health food stores.
Recommended daily allowance (RDA)
The RDA for iron is the daily iron intake required to meet the needs of most healthy individuals.
| Age | Men | Women |
|---|---|---|
| 1-3 years | 7 mg | 7 mg |
| 4-8 years old | 10 mg | 10 mg |
| 9-13 years old | 8 mg | 8 mg |
| 14-18 years old | 11 mg | 15 mg |
| 19-50 years old | 8 mg | 18 mg |
| > 50 years old | 8 mg | 8 mg |
| Age | ||
|---|---|---|
| Pregnancy | ||
| Any age | 27 mg | |
| Breastfeeding | ||
| ≤ 18 years old | 10 mg | |
| 19-50 years old | 9 mg |
Deficiency
Insufficient iron intake can lead to iron deficiency anemia, which causes the following symptoms:
- Fatigue
- Weakness
- Shortness of breath
- Pale skin
In addition, lack of iron can contribute to delayed growth and development in children and reduce the immune system's ability to protect the body.
Iron deficiency can be caused by various factors:
- Insufficient dietary intake
- Decreased absorption of iron by the body
- Increased use of iron by the body
- Significant loss of iron (e.g., during heavy menstruation)
If you have an iron deficiency, your health care professional may prescribe iron supplements. It's also important in such cases to increase your dietary iron intake.
Toxicity
Although rare, iron overload can cause gastrointestinal problems such as vomiting and diarrhea.
For individuals with certain diseases, taking high doses of supplemental iron can result in potentially toxic iron levels. Dietary sources of iron, however, do not appear to pose a risk of iron toxicity.
Supplements
Since a balanced diet usually provides the body with enough iron to maintain adequate iron stores, it isn't necessary to take iron supplements. However, they can be essential if you have anemia or if you are pregnant and unable to increase your iron intake by the recommended amount.
When iron supplements are used to treat anemia, they can cause stomach irritation and constipation. They can also turn stool and urine brown or black, and liquid forms can stain your teeth.
Iron absorption is optimal when supplements are taken without food. However, taking them with food improves digestive tolerance.
It's important to keep iron supplements in a safe place. Iron poisoning is a known cause of accidental death in children.
Always watch your diet:
it has a strong impact on your health!© Copyright Vigilance Santé
The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.