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Vitamin D supplements may reduce severe asthma attacks

Vitamin D supplements may reduce severe asthma attacksAccording to a Cochrane review, supplementing asthma medication with vitamin D may halve the risk of having a severe asthma attack and improve quality of life for those who suffer from this condition.

Around 300 million people in the world suffer from asthma, a chronic pulmonary inflammatory condition. The symptoms are recurrent attacks of gasping, coughing, and chest tightness caused by bronchial constriction. Asthma patients are more prone to fatigue and poor sleep due to their breathing difficulty, coughing, and airway infections, all of which impair their quality of life. Asthma affects all age groups, and around 50% of patients are children under the age of 10.

Vitamin D’s potential

Asthma attacks in adults and children are associated with low blood levels of vitamin D, which is why scientists have been interested in investigating the potential of this nutrient. First of all, vitamin D helps strengthen the immune system and reduce airway infections such as the common cold, which may exacerbate asthma. Secondly, vitamin D helps reduce inflammation.

Fewer asthma attacks and less need for medicine

Cochrane is a global, non-profit network of researchers, health professionals etc. interested in health, which analyses available research in order to clarify its meaning and make it more transparent. In the above case, researchers crunched the numbers of several studies with a total of 435 children and 658 adults. The study participants were from different parts of the world, and most had mild to moderate asthma, which means that they had symptoms at least two out of seven days each week.

In the course of the studies, which lasted between six and 12 months, most participants continued taking their asthma medication. The researchers observed that adding a vitamin D supplement in the range of 25-50 micrograms/day to their drug therapy reduced the risk of severe asthma attacks from six to around three per cent (a 50% reduction). Normally, these attacks require special attention and hospitalization.

Also, vitamin D supplementation lowered the patients’ need for treatment with corticosteroids, which is associated with numerous side effects. According to Professor Adrian R. Martineau from the Queen Mary University of London, adding vitamin D supplements to standard therapy may significantly reduce severe asthma attacks without causing side effects. However, the researchers need more data on how vitamin D affects asthma in children. They also need to find out if vitamin D only helps those asthma patients who have low vitamin D levels in their blood to begin with.

Vitamin D – a ”designer drug” for asthma patients

Professor Adrian R. Martineau who headed the above mentioned Cochrane review compares vitamin D with designer drugs, as the nutrient both strengthens the immune defense and curbs inflammation at the same time.

English health authorities recommend more vitamin D

Since July 2016, the English health authorities have recommended a daily 10 microgram vitamin D supplement for everybody from the age of one year – especially in the winter period where the sun sits too low in the sky for us humans to synthesize vitamin D ourselves.
The DRI (Daily Reference Intake) level for vitamin D in Denmark for children aged 1-10 years is 10 micrograms, while it is only 5 microgram for everyone from the age of 11 years and older. In other words, it is only 50% of the English recommendation. As mentioned earlier, the Cochrane asthma review shows that vitamin D supplementation in the range of 25-50 micrograms/day reduces the risk of severe asthma attacks – and this level is far beyond the official recommendations.

Upper safe intake level for vitamin D (revised in 2012)

There is much disagreement about the actual need for vitamin D, which depends on a number of different factors. The upper safe intake level for vitamin D as determined by the European Food Safety Authority (EFSA) is 100 micrograms for children older than 11 years and adults (including pregnant and lactating women).

Threshold levels in the blood

When measuring blood levels of vitamin D, the official threshold level is 50 nmol/l. However, leading experts claim that this level is insufficient and recommend levels up to around 75-100 nmol/l for optimal disease prevention.

Vitamin D, supplements, and absorption

Vitamin D is lipid-soluble. Therefore, the best absorption is obtained if you take the nutrient in an oil matrix in capsules.


Adrian R Martineau et al. Vitamin D for the management of asthma. Cochrane Library 2016

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