You may be familiar with Vitamin D and its benefits in supporting strong bones and boosting calcium absorption. But did you know that Vitamin D is also an important nutrient for maintaining a healthy immune system function?

Why is the Immune system important?

The immune system has a vital role. It is a complex network of organs, cells and chemicals that work hard to protect us from potentially harmful substances and germs that can make us ill.1, 2

As a general rule, our immune system becomes stronger during adulthood as it has been exposed to more germs over the years and we build up more immunity. This is why adults don’t tend to get sick as frequently as children do.2

There are 2 main parts to the immune system:

The Innate Immune System – this is the body’s first line of defense and consists of physical barriers such as your skin and mucous membranes which work to prevent harmful materials from entering your body. It also contains immune system cells and proteins which jump into action if germs do get past the initial barriers. The innate immune system is fast acting but non-specific as it responds in the same way to all foreign substances.3

The Adaptive Immune System is more complex and takes over if the innate immune system has not been able to resolve the issue. It is slower to respond but when it does, it is more specific as it specifically targets the type of germ involved. It has the ability to ‘remember’ germs so can elicit a faster response the next time round. This memory makes future responses against a specific germ more efficient and is also why there are some illnesses that you only get once in your lifetime.3

Why do we seem to catch more colds over winter?

On average, adults experience 2-5 colds per year.4  Although they can occur in any season, they are often more frequent in the colder months. There are several theories as to why this is the case:5, 6

  • During winter we spend more time indoors, meaning we’re in closer contact with other people and germ spreading is easier
  • Cold air cools the nasal passages and slows down mucus clearance which weakens the initial physical defence against germs
  • With more time indoors and shorter daylight hours we are more likely to have reduced exposure to sunlight which may affect our vitamin D levels (sunlight is our main source of vitamin D)

A healthy lifestyle for a healthy immune system

A healthy lifestyle is a good step towards supporting your immune system. Here are some helpful tips:7

  • Sleep – getting adequate sleep is important for immune system function. During sleep, certain components of the immune system increase in activity, strengthening adaptive immunity.8
  • Exercise regularly
  • Eat a varied diet with plenty of fruit and vegetables
  • Try to keep stress to a minimum
  • Don’t smoke – smoking can weaken your immune system and lower levels of protective antioxidants (such as vitamin C), in the blood 9, 10
  • Get some regular sunshine in your day to boost your natural production of Vitamin D which maintains healthy immune system function. If sun exposure is difficult, a vitamin D supplement may be of benefit.

Learn about which Ostelin product may be appropriate for you. 


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References available upon request.  
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