The best supplements to take during cold winter months include vitamin D due to the lack of sunshine.
However, a new study has found that topping up on the essential vitamin could also protect against severe asthma attacks too.
Asthma attacks can be more prevalent during winter because cold air in the airways can cause them to go into spasm, according to Asthma UK.
Researchers at Queen Mary University of London discovered that people who took oral vitamin D supplements in addition to standard asthma medication could halve their risk of an asthma attack that required hospital attendance.
It is thought vitamin D provides the beneficial effects by boosting immune responses to respiratory viruses and dampening down harmful airway inflammation.
Asthma causes 400,000 deaths annually, and fatalities usually happen because of attacks triggered by viral upper respiratory infections.
“These results add to the ever growing body of evidence that vitamin D can support immune function as well as bone health,” said Professor Adrian Martineau, lead researcher.
“On average, three people in the UK die from asthma attacks every day.
“Vitamin D is safe to take and relatively inexpensive so supplementation represents a potentially cost-effective strategy to reduce this problem.”
As well as asthma prevention and bone health, vitamin D has even more benefits.
“Vitamin D is vital for the optimum function of many body processes,” said Manal Chouchane, a clinical nutritionist for BioCare (www.biocare.co.uk).
“It is important for regulating our insulin production for optimum blood sugar balance, enhancing immunity, supporting cardiovascular health and enhancing our mood.”
While getting vitamin D from sun exposure is the most efficient way to absorb it, people can struggle to get enough during the winter months and there is also the risk of skin cancer.
Additionally, it is not possible to get enough vitamin D through diet alone, according to the Vitamin D Council, and particularly because natural levels in food have dropped.
“Food sources include oily fish, such as salmon, mackerel and sardines, eggs and raw milk,” explained Chouchane.
“However, due to the increase of fish farming and poultry, vitamin D levels in these sources are lower than expected.
“For example, farmed salmon was found to have approximately 75 per cent less vitamin D in comparison to wild salmon.”
The UK government now recommend every person takes a 10 microgram supplement of vitamin D daily.
Chouchane recommends buying vitamin D3.
“The form of vitamin D is important and choosing D3 as the form of vitamin D may be more effective than vitamin D2, as it is possibly metabolised much quicker,” she explained.
“As vitamin D is a fat soluble vitamin, it may be an issue for individuals with compromised digestion or who have difficulty digesting fats.
“Therefore, choosing an emulsified (pre-digested) version of vitamin D will ensure optimal absorption. I would recommend BioCare Nutrisorb Liquid BioMulsion D.”