Lack of vitamin D could be the cause of cold and flu.


You’ve probably been told to or have heard the saying in some form or another to wrap up warm when you’re going out in the cold because you don’t want to end up sick. Whilst colder temperatures itself doesn’t make you sick there are factors, that are linked to cold weather, that may contribute to a higher risk of contracting the cold or flu virus.  

The life of a virus. 

Rhinoviruses are responsible for causing the common cold and the influenza virus is responsible for causing the flu. Colonies of these viruses survive better in colder temperatures (below 37°C) and transmit from human to human by direct contact of through the air. The rhinovirus replicates better in colder temperatures whilst research shows the influenza virus has a coating that is more resilient in temperatures close to freezing therefore, making transmission of the virus more efficient.  

Your nose may not be as efficient. 

The nose acts as a great first line of defence when it comes to the fight against virus and bacteria. Nose hairs are there to act as physical barriers to trap infections from entering the lungs. In addition, cells in your nose produce mucus which also act to trap any bacteria of viruses. In winter the colder temperatures are likely to inhibit your nose from being able to trap and remove bacteria and viruses. The temperature of the nose on average during colder months is around 33°C compared to the body’s temperature which is around 37°C. This makes the nose a better environment for replication virus and bacteria.  

The warm indoors could be making you sick, ironic right? 

Let’s be honest, no one really loves to spend their time outside when temperatures are close to zero. People spend most of their time indoors during winter and obviously pre-COVID-19 days no social distancing would have been taking place! This means that the chances of picking up a virus from someone would be higher due to being around more people and in closer contact with them. Time to rethink that winter coffee date. 

Lack of Vitamin D 

During the winter months, there is less sunlight. Your body gets its vitamin D from the sun where around 30 minutes* of sun exposure a day should produce enough vitamin D (*varies depending on skin tone). Low vitamin D levels are linked to having a weakened immune response, therefore, if you have depleted levels of vitamin D and are exposed to a virus, the chances of you fighting it off will be decreased. This is why it is important for people who live in countries with winter months to take a daily dose of vitamin D to support your immune system in fighting cold and flu viruses. The Tonic Health immunity drink has a high dose of vitamin D to help you out during days where you aren’t feeling 100% to give your immune system the extra boost it needs. 

The well-known saying, “cold weather makes you sick” may have come about as an easier explanation to children. Understanding how the weather may impact the cold and flu virus and knowing how your body adapts to more extreme temperatures should help you in taking careful measures in protecting yourself in the winter season. 

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