is an essential nutrient in our bodies - and in all living organisms. Together with zinc, copper, vitamin K, folate and vitamin B12, iron is responsible for maintaining blood health. Healthy blood is important because our blood is responsible for transporting nutrients to organs and tissues. Without healthy blood, we could eat all of the nutrients in the world and it wouldn’t matter, because those nutrients would have nowhere to go without blood.
Why do we need it?
Iron is a component of numerous proteins in the body, such as hemoglobin and myoglobin. Hemoglobin is the protein found in red blood cells, responsible for transporting oxygen from our lungs to the organs or tissues where it is needed. About two-thirds of all our body’s iron can be found as hemoglobin. Myoglobin is the protein that provides oxygen to our muscles, so it plays a key role in energy support. Iron is necessary for growth and development, DNA synthesis and normal cell functioning.
Iron is also a trace mineral, which means it is a mineral essential to almost all of our bodily functions and is only required in small amounts. Our bodies also only store low amounts of it (2,5 - 4g in iron’s case). Despite this small amount, the WHO (World Health Organisation) lists iron deficiency as the most common nutrient deficiency in the world. Recent estimates put almost 80% of the global population at some level of iron deficiency.
How do we get enough iron?
We consume about 10-15mg of iron every day with our nutrition. From this amount, we are only able to absorb about 0,5-2mg of iron. Most of the iron needed comes from a recycling system in our body that takes the iron out of old red blood cells that are not functional anymore. As iron is such an important molecule, the body controls its metabolism very strictly because too much iron can be toxic.
There are several mechanisms involved in iron metabolism to make sure we get just the right amount of this important trace mineral. The most important ones are:
- Iron status in the body
- Level of dietary iron consumption
- Type of iron present in the food consumed
- Presence of other nutrients that can either increase or decrease iron absorption
There are two different types of dietary iron: heme and non-heme iron. In other words, iron from animal products (heme iron or Fe2+) and iron from plant products (non-heme iron or Fe3+). The bioavailability of iron (the part which is actually available for the body’s needs) is about 14-18% from mixed diets and 5-12% from vegetarians diets (1).
Research has proven that various nutrients or foods can influence the iron absorption. Let’s start with the ones that decrease iron absorption:
- Green tea (2): there are special plant molecules in green tea that can decrease iron absorption. If you are concerned about your iron intake, it is recommended not to have green tea at the same time with iron-rich food.
- Zinc (3): this only affects zinc supplementation with more than 10mg at once with iron intake. Zinc eaten naturally with food does not have such an effect. So check your supplement for zinc and iron levels.
- Fiber: fiber often slows down the absorption of micronutrients such as iron. It also decreases the absorption of sugar, which leads to less high glucose peaks in the blood.
- Calcium: the highest inhibiting effect was shown at about 300-600mg of calcium in the meal (4).
On the other hand, you can combine foods wisely to increase your iron absorption. Vitamin C (5) increases iron absorption. Have a glass of orange juice with your cereals in the morning or squeeze a bit of lemon over your oysters or clams. Meat protein such as fish, beef or poultry (6) also increases iron absorption. There are delicious plates like a fish curry with lentils that can help you increase your daily iron intake.
There is also a connection between iron deficiency and obesity. Research has shown that obese people (most of the research was done with children) are at higher risk to develop iron deficiency (7). So go out, play, run and have fun with your kids to stay healthy and in shape altogether.
Iron is needed in different amounts at different stages or circumstances of our lives.
There are especially high needs in pregnancy and in women in general because of the blood loss with menstruation. Infants also have a very high need because it is essential for a lot of developmental processes like brain development for instance.
Recommended daily amount
Birth to 6 months
Infants 7-12 months
Children 1-3 years
Children 4-8 years
Children 9-13 years
Teens boys 14-18 years
Teens girls 14-18 years
Adult men 19-50 years
Adult women 19-50 years
Adults 51 years and older
Source: National Institutes of Health - Office of dietary supplements
As already mentioned, the bioavailability of iron coming from animal products is much higher than from plant products. Excellent iron sources are all innards, for those who like it. Beef liver, for example, has 4,06mg iron / 85g, which is about 22% DV (Daily Value)*. But it is still possible to get the recommended daily iron amounts through a plant-based diet, and some plant sources are even higher than animal sources. An excellent plant-based source of iron is the algae spirulina, with 8mg per 33g, which is about 44% DV. Legumes are also a very good source, and to increase the absorption it can be mixed with some animal protein. For those with a sweet tooth, dark chocolate comes with 3.3mg iron per 30g (19% DV).
* DV = Daily Value. The DV for iron is 18 mg for adults and children age 4 and older. Foods providing 20% or more of the DV are considered to be high sources of a nutrient.
As the WHO study revealed, around 80% of the population has some level of iron deficiency.
Symptoms of iron deficiency are (7):
- Gastrointestinal issues
- Impaired cognitive function
- Inability to perform exercise
Although iron deficiency is common, it is important not to go overboard on your iron intake. As already mentioned, an excessive iron intake (mainly from supplements) can be toxic. An amount of more than 20mg/kg body weight can lead to gastric upset, constipation, nausea, abdominal pain, vomiting, and faintness, especially taken on an empty stomach or without food. Amounts higher than 60mg/kg body weight can lead to multi-organ system failure and even to death.
Iron is one of the most important trace minerals. It transports oxygen to the organs, tissues, and cells where it is required. Without iron, we could not survive. There are two different types of iron depending on the origin. Iron from animal food sources (heme iron) can be absorbed easily whereas iron from plant-based sources (non-heme iron) is absorbed in smaller amounts and has to be prepared before absorption in the digestive tract. There are nutrients that increase or decrease iron absorption. There are different daily needs for iron established regarding ages, gender and life circumstances, such as pregnancy. Excessive iron intake can be toxic.
Want to add more iron to your diet? Try our Wake Up organic superfood powder mix, which is a good source of daily iron.