Micronutrient Deficiency: A Key Factor That Can Be Targeted In Managing Allergy

Atopic allergy diseases can occur as a result of an exaggerated immune response by the body following exposure to a trigger allergen. It can manifest itself in the form of atopic respiratory conditions such as allergic rhinitis and allergy asthma, skin conditions such as atopic dermatitis and even the gut as food allergies. Conventional management of atopic disease involves avoidance of the trigger allergens, optimization of symptomatic medications such as antihistamines and steroids. 

We cannot deny the evidence of genetic predisposition in some towards allergy. However, there are increasing medical evidence to suggest epigenetic factors such as our nutritional status of the body can overtime contribute to a person’s predisposition of developing allergy.

In this article, we highlight the connection between micronutrient deficiency and development of allergy. The understanding of the link between the two can have an impact to the current management of allergic conditions.

Iron

Iron is an element that can be found on earth ubiquitously. It is found in most living things that requires oxygen. It helps in the respiration of cells and has a role in the general immune system. 

Our body contains 4-5g of iron. Two third of the iron is stored in a part of red blood cells known as heme (hence red cell is known as hemoglobin). A large amount of iron is also kept in the liver and a type of white cells known as the macrophages. Lesser, iron is also kept in the muscle proteins known as myoglobulins. 

In our body, the iron usually presents as ferrous (Fe2+) or ferric (Fe3+) state. In environment that is rich in oxygen, free iron tends to be in ferric (Fe3+) state, while in environment lack of oxygen, iron tends to be in ferrous state(Fe2+). Iron is usually bound to protein- such as in the case of hemoglobin, transferrin etc.

Although on average we consume 10-20mg of iron from our diet only 1-2 mg is being absorbed daily. The iron is absorbed in the small intestines (the duodenum and jejunum).

How can we be deficient in iron?

A third of the people in the world has iron deficiency. Iron deficiency is more predominant in female, blood donors, vegetarians and growing infants. The World Health Organization (WHO) defined anemia as hemoglobin levels <12g/dL in female and <13g/dL in men. However, hemoglobin level can vary due to ethnicity or even if one is living in high altitude.

Logically, there are two common causes of iron deficiency- either we lose the iron through bleeding such as menstrual cycle, or we do not receive adequate iron from our diet in the case of vegetarians etc. 

Interestingly, there is a third reason for iron deficiency- functional iron deficiency. In functional iron deficiency, there is immune response activation, leading to ‘immobilization’ or ‘underutilization’ of the iron in the body. To make things worse, there is reduced ability of absorption of iron from the diet during immune inflammatory response. Functional iron deficiency can occur as a result from chronic medical conditions such as infection, heart failure, allergy, chronic kidney disease, autoimmune or even obesity.

The Interlink between Atopy Diseases and Micronutrient Deficiency

While we know allergies or atopy conditions tend to be genetically predisposition, environmental factor such as micronutrient status can contribute to allergy as well.

It is known that those who are pregnant with iron deficiency increases chance of having infants with allergy. Intriguingly, one with allergy is also more at risk of having anemia. Children with atopy such as eczema, asthma, allergic rhinitis, food allergy have higher association with anemia.  Expectedly, avoidance of development of allergy can occur in those with improvement of iron levels.

Furthermore, micronutrients such as vitamin D, folic acid, vitamin A, zinc also have a role in our genetic makeup and immune system surveillance. 

In those with deficiency in micronutrients, the immune cells in the body can be in a constant ‘heighten-alertness’ state. Lack of these minerals are associated with increased inflammatory response when encountering allergen, resulting in exaggerated immune response when the body encounters allergens or triggering proteins.

How do our Immune Cells Behave when we are Deficient in Micronutrients?

Macrophage - a type of white cells found in all tissues and blood circulation –serve as the soldier of our body to monitor and guard against pathogens. At rest and baseline, macrophage also help to store iron minerals in the body. In the state of persistent iron deficiency, there is a shift of the function of macrophages (rather than storing iron) to pro-inflammatory state, leading chronic low grade inflammatory response in the body and at risk of developing allergy.

In addition, when one is deprived of sufficient iron in the body, mast cells- an immune cell which has a significant role in allergy and infection- also become unstable. The mast cells contain small pockets of proteins known as histamine granules. When they are unstable, the granules are ‘ready to burst’, releasing histamine that contributes to inflammation and allergy.

In summary, iron deficiency can have a pro-inflammatory effect to the immune cells, leading to disequilibrium function of immune cells, producing exaggerated inflammatory response and allergy symptoms.

Can we screen for micronutrient deficiency?

Yes, micromineral levels such as iron, vitamin D, zinc, folic acid levels can be safely tested through blood tests.

What can we do if we are low in micronutrients?

Having a daily healthy and balance diet is key in receiving sufficient nutrient for the body. 

A variety of diet rich in micronutrients such as red meat, fish, innards, chocolate, legumes, cereals, fruits, fortified milk, whey protein, fruits, vegetable, legumes can be beneficial in reducing risk of developing allergy.

Perinatal healthy nutrients rich in iron, zinc, vitamin A, D, vitamin C are vital in determining the health of future offspring and reducing the risk of developing allergy, thereafter avoiding atopic march in the future offspring.

In the case of insufficiency of micronutrients from our daily diet, oral supplement can be used to boost the levels of micronutrients in our body.

Take home message: 

Maintaining sufficient micronutrient levels as a potential in alleviating allergy disease

Improving the micronutrient levels in the circulation can result in a more stable and resilient immune system, preventing chronic inflammation and allergy.

Boosting and compensating micronutrient deficient level in pregnant mother and infants has shown to improve overall immune cell inflammatory response, reducing risk of atopy in infants and potentially halting the progress of atopic march in later life.

Fascinatingly, intervening and targeting micronutrient deficiency can be considered as an ‘allergen-independent’ way of stabilizing the immune response, alleviating and controlling atopy symptoms.

If you're experiencing persistent allergy symptoms, a deeper look into your micronutrient levels could offer valuable insights. Schedule a consultation with Dr. Ben Medical Clinic to explore a personalised allergy treatment in Singapore.

References:

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3.  Roth-Walter F. Iron-Deficiency in Atopic Diseases: Innate Immune Priming by Allergens and Siderophores. Front Allergy. 2022 May 10;3:859922.
4. Drury KE, Schaeffer M, Silverberg JI. Association Between Atopic Disease and Anemia in US Children. JAMA Pediatr. 2016;170(1):29-34.