- Asthma is a chronic lung disease characterized
by recurrent attacks of breathlessness and wheezing.
vitamin D levels have been linked to increased asthma attacks.
- Vitamin D supplementation in addition to standard asthma
treatment reduced the risk of severe asthma.
New evidence from randomized
trials now reveals that taking an oral vitamin D supplement in addition to
standard asthma medication is likely to reduce severe asthma attacks.
The potential of vitamin D in asthma management
has been of
much interest, as low vitamin D levels have been linked to increased asthma
attacks. Role of vitamin D
has been tested in clinical trials, especially
by its effect on acute and severe attacks of asthma, the symptoms and any
change in the lung function among all age groups suffering from asthma.
‘An oral vitamin D supplementation reduced the risk of severe asthma attacks requiring hospital admission or emergency department attendance from 6% to around 3%.’
is a disease condition that affects the
airways. The disease is often associated with breathlessness and wheezing that
occur at recurrent intervals and vary in frequency and severity. It attacks all age groups but often starts in childhood.
- Around the world, it is estimated that 300 million people suffer
from asthma, by the year 2025 this figure may rise to 400 million.
India, rough estimates indicate a prevalence of between 10% and 15% in
5-11-year old children.
- World-wide, the economic costs
associated with asthma are estimated to exceed those of tuberculosis (TB) and
- The burden of the disease is worrying
and WHO experts are struggling to understand why rates world-wide are, on
average, rising by 50% every decade.
The team of Cochrane researchers
found seven trials involving 435 children and two studies, involving 658 adults.
The study participants were
ethnically diverse, reflecting the broad range of global geographic settings,
involving Canada, India, Japan, Poland, the UK, and the US The majority of
people recruited to the studies had mild to moderate asthma, and a minority had
Most people continued to take
their usual asthma
in the studies. The studies lasted for between six and 12 months.
- An oral vitamin D supplementation reduced the risk of
severe asthma attacks requiring hospital admission or emergency department
attendance from 6% to around 3%.
- Vitamin D supplementation
reduced the rate of asthma attacks needing treatment with steroid tablets from 0.44 to
0.28 attacks per person per year.
- But vitamin D did not
improve lung function or day-to-day asthma symptoms.
was no increase in the risk of side effects at doses of the vitamin D that were
The Cochrane Review's lead
author, Professor Adrian Martineau from the Asthma UK Centre for Applied
Research, Queen Mary University of London, said, "This is an exciting
result, but some caution is warranted. First, the findings relating to severe
asthma attacks come from just three trials: most of the patients enrolled in
these studies were adults with mild or moderate asthma. Further vitamin D
trials in children and adults with severe asthma are needed to find out whether
these patient groups will also benefit. Second, it is not yet clear whether vitamin
D supplements can reduce risk of severe asthma attacks in all patients, or
whether this effect is just seen in those who have low vitamin D levels to
start with. Further analyses to investigate these questions are on-going, and
results should be available in the next few months."
He also pointed out that in the
study, vitamin D was added on to asthma medication the patients were already
taking. He explained: "We don't want people giving up taking their asthma
He also warned against taking
vitamin D without advice.
"Going to see your GP is a
key part of the message we want to give - I don't think it would be appropriate
to just start taking vitamin D without knowing whether you have vitamin D
deficiency or not and we don't yet know what the threshold of vitamin D is
below which you will have a benefit."
About Vitamin D
- Vitamin D is a fat-soluble vitamin that is naturally
present in foods like fish oil, fatty fish, mushrooms, egg yolks.
- When ultraviolet rays of the sun strike
the skin, vitamin D synthesis in our body begins, this
is our source of vitamin D and hence the name "sunshine vitamin".
- It is also available as a dietary supplement or as Vitamin
D fortified food products such as cereals, juice and milk.
- Vitamin D promotes calcium
absorption and prevents rickets (softening and weakening of bones in children)
in children, while preventing osteoporosis and
osteomalacia in adults.
- It also helps in cell growth,
neuromuscular and immunological function
concentration of 25(OH)D is the best indicator of vitamin D
The Cochrane review has been
published in the Cochrane Library.
- Vitamin D - (https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/)