A study in the Asia Pacific journal of clinical nutrition in 2025 systematically reviewed dozens of papers in low- and middle-income countries and concluded that iron interventions, whether in supplements, fortified foods or dietary strategies, are associated with more haemoglobin and less iron deficiency anaemia. This matters in everyday life because anaemia translates into constant tiredness, reduced performance and increased physical vulnerability.
For people in these regions, the finding reinforces that acting early on iron deficiency can make a difference in energy, work capacity and child development. The results are especially relevant for women of childbearing age, children and adolescents, who tend to be the groups most affected when dietary iron deficiency or increased losses occur.
What the systematic review on iron and anaemia looked at
The systematic review brought together studies conducted in several low- and middle-income countries, with different ages and settings. The papers included trials of iron supplements, iron-fortified food programmes and dietary changes aimed at increasing iron intake.
The authors assessed how these interventions influenced haemoglobin, the oxygen-carrying protein in the blood, and the prevalence of anaemia. In most studies, clear improvements were observed, although in some cases anaemia even worsened, despite using doses considered standard.
The researchers stress that success does not depend only on the amount of iron. Factors such as the presence of other micronutrients, adherence to supplementation, nutritional education and the usual diet of the population modify the final outcome.
How iron works in the body and why it has such an impact on fatigue
Iron is an essential mineral for making haemoglobin, which enables red blood cells to carry oxygen to all tissues. When iron is lacking, the blood carries less oxygen, leading to feelings of fatigue, shortness of breath on exertion and reduced ability to concentrate.
In addition to its role in haemoglobin, iron is involved in enzymes that produce energy in the mitochondria, which are the power plants of the cells. Therefore, prolonged deficiency not only reduces red blood cells, but also affects overall energy metabolism.
The systematic review shows that when this deficiency is corrected with supplements, fortified foods or dietary improvements, haemoglobin levels usually rise and anaemia decreases. In practice, this translates into more vitality and better tolerance to everyday exertion.
Daily habits that support iron and energy status
The study focuses on countries with limited diets, but offers useful lessons for everyone. Maintaining good iron status depends on what we eat, how we combine foods and our blood losses.
In the diet, animal sources of iron such as lean meats and fish help, as do plant sources such as legumes and nuts. Vitamin C in fresh fruit and vegetables improves the absorption of vegetable iron, so combining them in the same meal is a simple strategy.
It is also advisable to moderate the consumption of tea and coffee just with the main meals, as they can reduce iron absorption. In women with heavy periods or people on very restrictive diets, watching for energy, paleness and shortness of breath may be a sign to check iron status with a professional.
How an iron complex with vitamins can align with this evidence
The systematic review focuses on the idea that providing adequate iron helps prevent and correct iron deficiency anaemia. A supplement such as an iron complex with vitamins builds on that same logic, providing iron in oral form along with micronutrients involved in normal red blood cell formation and energy metabolism.
This type of formulation typically includes iron in a form designed to promote absorption, along with B vitamins and vitamin C that contribute to normal red blood cell formation, immune system function and the reduction of tiredness and fatigue. The combination seeks to support, in a coordinated way, the production of haemoglobin and the efficient use of energy in the body.
It is intended for adults who already take care of their diet and physical activity and want additional support when they feel their daily energy is lacking, or belong to groups with higher iron requirements, such as women of childbearing age. It should always be understood as a complement to healthy habits, not as a substitute for a varied diet.
Supplementation with iron and vitamins to support the formation of red blood cells and the reduction of fatigue within a healthy routine.
Final summary, iron, energy and informed choices
Systematic review in low- and middle-income countries shows that iron interventions, in the form of supplementation, fortification or dietary changes, are generally associated with higher haemoglobin and less iron deficiency anaemia. The magnitude of benefit depends on context, diet quality and adherence to interventions.
In daily life, taking care of nutrition, watching for signs of persistent fatigue and, when necessary, considering nutritional support with iron and vitamins can help sustain energy and the ability to cope with daily tasks. This content is for information only and is not a substitute for the advice of a healthcare professional.
Frequently asked questions
What did the systematic review on iron supplementation show?
The review found that most iron interventions in low- and middle-income countries were associated with higher haemoglobin levels and a lower prevalence of iron deficiency anaemia. The effect was clearest when the interventions were well designed and accompanied by nutrition education.
Why does iron deficiency anaemia cause so much fatigue?
Iron deficiency anaemia reduces the amount of haemoglobin available to carry oxygen. With less oxygen, muscles and brain work harder, resulting in fatigue, shortness of breath on exertion and reduced ability to concentrate in daily life.
Is it enough to improve the diet to take care of iron or is supplementation necessary?
For many people, a balanced diet with sources of iron and vitamin C may be sufficient to maintain adequate levels. However, in contexts of high demand, increased losses or very limited diets, the review shows that supplementation and food fortification can be useful tools to reduce anaemia.
What is the role of vitamins in a vitamin-iron complex?
Vitamins, especially some B vitamins and vitamin C, are involved in normal red blood cell formation and energy metabolism. In an iron complex with vitamins, these nutrients are combined to support iron utilisation and contribute to the reduction of tiredness and fatigue within a healthy routine.
Who might an iron complex with vitamins make the most sense for?
It may make sense for adults with poorly varied diets, women of childbearing age with significant menstrual losses, or people who notice persistent fatigue and wish to support their red blood cell formation and energy metabolism. It should always be integrated into an approach that includes a balanced diet and professional monitoring where necessary.
