The role of vitamin D for a stronger immunity in winter

Vitamins & minerals
Eléonore de Maurissens
Reading time: 3 minutes
De rol van vitamine D voor een sterkere immuniteit in de winter

How can we best prepare our bodies for winter? There are several methods: focus on sleep, exercise, and nutrition at the same time. Together, they have a strengthening effect. For example, optimizing your vitamin D levels helps to boost your immune system.


In winter, our bodies can be deficient in certain vitamins and minerals. We may, in fact, need extra vitamins D and C, magnesium, selenium, and zinc. Vitamin D has a unique property: it is the only one the human body can produce itself through the absorption of sunlight by the skin. The other vitamins and minerals can only be obtained through diet. Due to the lack of sunlight in winter, a vitamin D deficiency is common, which can weaken the immune response.

 

Why is vitamin D so important for our immunity?

Vitamin D is essential for regulating our immune system. This vitamin helps activate the immune system by stimulating the production of antimicrobial peptides and by modulating the inflammatory response. As multiple studies1,2 show, a vitamin D deficiency can be linked to an increased risk of respiratory infections, such as colds, the flu, and even COVID-19. Vitamin D also plays a role in modulating immune responses, both innate and adaptive (immunity built up over a lifetime). This allows the body to better recognize and neutralize pathogens (such as bacteria and viruses).

Thanks to vitamin D, the body can better recognize and neutralize bacteria and viruses

How can you optimize your vitamin D levels in winter?

1. Through sun exposure. The skin produces vitamin D when exposed to UVB rays. In summer, 10 to 30 minutes of direct sun exposure (without sunscreen) a few times a week can be enough to maintain your vitamin D levels. In winter, however, this is often insufficient, especially in regions like Belgium! More generally, it is difficult to produce enough vitamin D in Northern Europe through sun exposure between October and March. Therefore, a vitamin D supplement is recommended during these months.3
2. Through a vitamin D supplement. During winter, a vitamin D supplement is essential to compensate for the lack of sunlight.3 The exact dose may vary depending on your age, weight, and skin color. Your doctor can advise you on whether you should start taking a vitamin D supplement based on your profile.
3. Through vitamin D-rich nutrition. Although you often cannot get enough vitamin D from food alone, certain foods are rich in this vitamin:

  • fatty fish (salmon, mackerel, sardines),
  • dairy products fortified with vitamin D,
  • eggs,
  • certain mushrooms (such as chanterelles, porcini, or morels).

Supporting our defense mechanism: thanks to vitamin D, but also…

In summary, we ensure a solid foundation with sufficiently high vitamin D levels through a combination of sun exposure (when possible), specific nutrition, and a supplement. For an optimal effect in generally supporting the immune response, this strategy can also be combined with:

  • quality sleep (7–9 hours of sleep for an adult),
  • nutrition with a high concentration of nutrients such as vitamin C4, zinc, and selenium, for a stronger immune system;
  • "anti-inflammatory" nutrition, rich in antioxidants (fiber, omega-3 fatty acids, and colorful vegetables);
  • moderate physical exercise5.

These actions work in synergy to strengthen the immune system. If you focus on your vitamin D levels first and gradually adopt these other habits, you should notice the health benefits for your immunity this winter.

 

Do you pay attention to your vitamin D levels? How do you ensure you get as much vitamin D as possible to armor yourself against winter? Share your experiences on our Facebook and Instagram!

Scientific references

  1. Grant W.B., Lahore H., McDonnell S.L., Baggerly C.A., French C.B., Aliano J.L., Bhattoa H.P.: "Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths", 2020, Nutrients, 12, 988.
  2. Gibbons J.B. & al.: "Association between vitamin D supplementation and COVID-19 infection and mortality", 2022, in Nature 12:19397.
  3. David A. Jolliffe, Carlos A. Camargo, John D. Sluyter, Mary Aglipay, John F. Aloia, Davaasambuu Ganmaa, & al.: "Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials", 2021, The Lancet Diabetes & Endocrinology, doi: 10.1016/s2213-8587(21)00051-6.
  4. Anitra C. Carr, Silvia Maggini: "Vitamin C and Immune Function", 2017, Nutrients, 9(11), 1211.
  5. J. Romeo, J. Wärnberg, T. Pozo, A. Marcos: "Physical activity, immunity and infection". June 2010, Cambridge University Press.

Product mentioned in this article

Selenium-ACE+D+ZN

Do you want to support your body daily with essential vitamins and minerals? Selenium-ACE+D+Zn combines selenium, vitamins A, C, D and E, and zinc in one complete once-a-day formula. Ideal as a daily supplement, but also during the winter months, busy periods, or in case of fatigue.
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