What You Need to Know:
- Iron is an important mineral involved in many processes in the body, like oxygen transport.
- The body needs more iron during adolescence due to growth and the onset of menstruation.
- Physical activity and sports increase iron requirements.
- It is easy to become iron deficient if one is not careful about the diet.
- Here we cover some of the tricks to increase iron absorption from food.
- Iron supplements are not necessary and can be dangerous.
Adolescents need to get sufficient quantities of iron from their diet as it is a key nutrient for their growth and development.
During adolescence the body requires more iron because this is a phase of physical intense growth and development which requires a higher blood volume. The onset of menstruation in adolescent girls also means that more iron is needed.
Furthermore, physical activity increases the requirement of iron due to increased losses of iron from the body.
Iron deficiency, which can eventually lead to iron-deficiency anaemia is a common nutritional deficiency worldwide among adolescents. This is due to their higher needs coupled with the fact that many adolescents often consume monotonous and unbalanced diets that may negatively affect the intake of iron.
Unfortunately, preventing iron deficiency is not as easy as eating iron-rich foods and supplementing with an iron supplement.
There are a lot of dietary factors that affect the amount of iron from food that enters the circulation and care must be taken when planning diets.
Supplementation, especially in high doses, is problematic because of potential toxicity issues in the long run and, more acutely, gastrointestinal issues like constipation.
The South African department of health sets the daily requirement (Nutrient Reference Values-NRV) of iron at 18mg per day for individuals 4 years and older.
Iron Deficiency Symptoms
The common symptoms of iron deficiency are reduced memory, concentration and a reduced ability to learn new things.
In a study done in 5398 children aged 6-16 years in the United States, it was found that children with iron deficiency had greater than twice the risk of scoring below average in math than did children with normal iron status (1).
Fatigue is also among the most common symptoms as reduced iron levels mean that less haemoglobin is available in blood to carry oxygen. Tasks like climbing stairs, walking uphill or exercising become harder.
The heart also beats faster (higher pulse rate) in its attempt to maintain oxygen circulation.
To ascertain the iron levels blood tests are recommended that more accurately give you an idea of iron levels in the body.
However, keep in mind that iron deficiency can have causes that are not related to nutrition and the proper diagnosis conducted by a healthcare professional, is important.
Obtaining Iron from Food
It is recommended to obtain iron from food. Supplements may be considered only under recommendation by a healthcare professional.
Types of food Iron
There are two forms if iron in food, name haeme and non-haeme iron.
Haeme iron: found animal sources like meats, fish and shellfish.
Non-haeme iron: found in plant sources like dark-green leafy vegetables (e.g. Spinach), dried fruits and beans.
Ensuring efficient Iron absorption
In terms of absorption, haeme is much better absorbed than non-haeme iron.
This is because non-haeme iron is susceptible to inhibition by a number of dietary factors which reduce the bioavailability of non-haeme iron. These factors are:
□ Calcium: present in dairy products. Calcium competes against Iron for absorption at the intestines as they use the same transporter.
□ Phytates (present in cereals and grains) and Polyphenols (present in tea and coffee) that bind non-haeme iron making them unavailable for absorption.
All hope is not lost because your body can still absorb non-haeme iron if facilitators are taken in in the meal containing non-haeme iron. These facilitators are Vitamin C and Vitamin A.
Vitamin C is a powerful stimulator of non-haeme iron absorption. My honours thesis was on this very topic (thesis title, “Determinants of Bioavailability in Iron Nutrition: Vitamin C as a Knight in Shining Armour”)
Iron supplements are not recommended unless prescribed by a healthcare professional.
Self-administration of iron can be hazardous because long-term consumption can lead to accumulation of iron in body tissues like the liver.
Excessive iron intake can also cause constipation.
Iron is present in many foods as a fortificant (e.g. in flour and cereals) or in nutritional shakes and multivitamins. These are generally not reason for concern as they are present in small amounts.
Putting it all together
□ Consume animal sources: these supply haeme iron that are efficiently absorbed. This is a good way to reverse deficiency.
□ Eat a source of Vitamin C: vitamin C helps with iron absorption and can improve the absorption of non-haeme sources.
About the Author
MSc (Med) Exer. Sci (UCT) cum laude, BSc (Hons) Biology.
Veeraj is an exercise and nutritional scientist by training and profession. He is passion revolves around researching and developing nutritional products for optimal health and performance, with a particular interest in sports, child and diabetic nutrition products. Veeraj was previously a graduate student at the University of Cape Town, where he examined how exercise and nutrition influence the function of genes in muscle. His research was published in renowned scientific journals and medical textbooks on Diabetes and Exercise (PubMed listing). Veeraj keeps healthy by regularly lifting weights and takes daily walks.