Childhood asthma may be linked to vitamin D and magnesium deficiency

- plus too much sugar

A growing number of children are affected by asthma, which is associated with a reduced quality of life. Diet plays a significant role in the development of the disease, and it appears that excessive sugar intake from breakfast cereals, soft drinks, candy, and other sources increases the risk. A deficiency in vitamin D and magnesium, which is widespread, also raises the risk according to an article published in Frontiers in Nutrition. But why does sugar increase the risk of developing asthma, and how can vitamin D and magnesium help protect against the disease?

Asthma is a chronic respiratory disease characterized by persistent inflammation in the lungs, narrowed bronchi, and symptoms such as shortness of breath, coughing, and chest tightness. There is also a higher risk of fatigue and poor sleep due to the symptoms. Additionally, asthma patients are more vulnerable to respiratory infections, which can themselves trigger an attack. Globally, around 300 million people suffer from asthma, many of whom are children. It is well known that tobacco smoke and other air pollution can increase the risk. It is also known that a healthy and varied diet can reduce the risk by strengthening the immune system and gut flora. In the new study, researchers wanted to examine the connection between asthma development and nutrient intake from diet. They used a method called Mendelian randomization (MR), which examines genetic variants and various environmental influences. To do this, they gathered data from several databases, including FinnGen and GWAS. They also analyzed the dietary intake of:

• Macronutrients (carbohydrates, fats, protein, and refined sugar)
• Vitamins (A, B6, folic acid, B12, C, D, and E)
• Minerals (calcium, magnesium, copper, selenium, zinc, iron, phosphorus)
• Specific antioxidants (lycopene, beta-carotene)

This study revealed an inverse relationship between sugar intake and the risk of developing childhood asthma. In other words, the more sugar a child consumes from breakfast cereals, candy, soft drinks, fruit juice, cakes, ketchup, and other hidden sources, the greater the risk of developing asthma. The study also showed that low blood levels of vitamin D and magnesium increase the risk of asthma.

Why is sugar so unhealthy?

Sugar belongs to the category of refined, empty calories that lack micronutrients such as vitamins and minerals. When the body processes these calories for energy, it must draw on various vitamins and minerals from other sources to facilitate numerous enzymatic processes. This can lead to deficiencies, including magnesium, which plays many roles in the body. Consuming large amounts of fast-acting carbohydrates like sugar also causes a sharp rise in blood sugar and insulin levels, increasing the risk of magnesium excretion through urine. Furthermore, sugar can negatively impact gut flora and the immune system.

How does magnesium protect against asthma?

Magnesium, one of the body's essential minerals, is involved in over 300 enzymatic processes that are crucial for energy metabolism and overall health. It also plays a role in immune function and regulates inflammatory processes involved in asthma. Another critical function of magnesium is its role in regulating calcium distribution in the body, ensuring that most calcium is stored in bones while keeping cells in the airways and other soft tissues nearly free of calcium. When there is too little magnesium, excessive calcium can enter these cells, leading to overstimulation and stress. This can increase the risk of chronic inflammation. For this reason, asthma patients should be particularly aware of the balance between calcium and magnesium, as excessive calcium from dairy products and supplements combined with insufficient magnesium can increase the risk of inflammatory conditions in the airways and subsequent asthma attacks. Magnesium is thus considered a calcium antagonist. Moreover, magnesium is essential for activating the form of vitamin D that the body synthesizes from sunlight or receives from supplements. Good sources of magnesium include oatmeal and other whole grains, nuts, seeds, avocado, cabbage, and other vegetables. The daily reference intake (RI) for children is set at 85 mg, while it is 375 mg for children over 11 years and adults.

How does vitamin D protect against asthma?

Vitamin D supports immune function by helping the body combat viruses, bacteria, fungi, and toxins. Additionally, vitamin D helps regulate inflammatory processes, preventing them from becoming excessive and chronic. In other words, vitamin D protects against respiratory infections and the chronic inflammation in the airways that contributes to asthma development.
A meta-analysis from Queen Mary University of London (QMUL) previously revealed that vitamin D supplementation (25-50 micrograms daily) combined with standard asthma medication can halve the risk of asthma attacks that would require hospitalization. Vitamin D supplementation also reduced the need for corticosteroid treatment, which is associated with many side effects. Deficiency in vitamin D is particularly common in northern latitudes because the sun is too low in the sky throughout the winter for natural vitamin D synthesis. Additionally, many children are covered in so much sunscreen that it inhibits the skin's vitamin D production. For this reason, it is important not to fear sun exposure but rather to avoid sunburns. The Danish Veterinary and Food Administration recommends that children up to four years of age take vitamin D supplements year-round. Supplementation is also advised year-round for those who do not get sufficient summer sun or have darker skin.
Nevertheless, official recommendations for vitamin D remain relatively low for both children and adults (5-10 micrograms), whereas asthma patients benefit from higher doses to support the immune system and to reduce chronic airway inflammation. In this context, the European Food Safety Authority (EFSA) has set an upper limit for daily vitamin D intake at 25 micrograms for infants, 50 micrograms for children (1-10 years), and 100 micrograms for older children and adults. This is not more than what most fair-skinned individuals can produce on a sunny summer day with light clothing. Since vitamin D is fat-soluble, the best absorption is achieved by taking supplements in capsule form, where vitamin D is bound to oil.

References:

Liang Luo et al. Dietary intake, antioxidants, minerals and vitamins in relation to childhood asthma: a Mendelian randomized study. Frontiers in Nutrition. 2024

Nicola Veronese et al. Effect of Magnesium Supplementation on Inflammatory Parameters: A Meta-Analysis of Randomized Controlled Trials. Nutrients 2022.

David A Jolliffe et al. Vitamin D supplementation to prevent asthma exacerbations: systematic review and meta-analysis of individual participant data. The Lancet Respiratory Medicine 2017