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LMU 161 – Unlocking the Power of Vitamin D: A Shield Against Respiratory Infections


LMU 161 – Unlocking the Power of Vitamin D: A Shield Against Respiratory Infections

Source: PLOS journal June 2013

Lifestyle Medicine Update (May 2, 2020)


Vitamin D is a vital player in immune health, influencing our body’s ability to fend off respiratory tract infections. However, maintaining the right balance is key, as both low and excessively high vitamin D levels pose risks. This delicate equilibrium can impact our immune response. In this discussion, we explore how optimizing vitamin D levels can enhance immunity and prevent respiratory infections, providing insights into the importance of maintaining this essential nutrient at the right levels.

The Vitamin D Revolution in Respiratory Health

In the battle against respiratory tract infections, science has uncovered a potent ally: Vitamin D. A groundbreaking review article, “Vitamin D and Respiratory Tract Infections,” published in 2013 by Bergman et al., sheds light on the profound impact of this humble vitamin on our immune system’s ability to fend off invaders [1].

The Critical Connection Between Vitamin D and Immunity

The review encompassed data from eleven placebo-controlled studies, involving a total of 5,660 patients. What emerged from this meticulous analysis were revelations that could reshape our approach to preventing respiratory infections.

  • Optimal Levels for Immunity
  • One of the central findings of the review is the importance of maintaining optimal vitamin D blood levels. Individuals with vitamin D levels below 75 nmol/L (30 ng/ml) were found to be at a higher risk of respiratory tract infections. This observation aligns with the crucial role vitamin D plays in our immune system.

    Vitamin D acts as a catalyst for immune cells lining the respiratory tract, enabling them to synthesize molecules that act like molecular daggers. These molecules puncture viruses and bacteria, swiftly neutralizing them before an infection takes hold.

  • The Double-Edged Sword of Vitamin D
  • Surprisingly, the study also illuminated a paradoxical aspect of vitamin D. While too little can leave us vulnerable, too much can be detrimental. Individuals with vitamin D levels soaring above 140 nmol/L (56 ng/ml) were found to have an increased susceptibility to respiratory infections. This paradox can be attributed to vitamin D’s impact on the release of certain cytokines, key players in the adaptive immune system’s response.

    In autoimmune conditions like Multiple Sclerosis, high doses of vitamin D have shown promise. They help modulate the overactive behavior of T and B-lymphocytes, which are notorious for exacerbating inflammation and demyelination in the disease. This modulation can induce remission or sustain it, offering hope to those affected.

Vitamin D Deficiency – A Widespread Problem

In light of these findings, the prevalence of sub-optimal vitamin D levels in society becomes a pressing concern. A significant portion of the population falls below the 75 nmol/L (30 ng/ml) threshold. This deficiency, it seems, could be a silent contributor to the burden of respiratory infections.

  • The Call for Supplementation
  • The implications are clear: for many, vitamin D supplementation could be a game-changer. Elevating vitamin D levels above the 75 nmol/L mark appears to confer a significant reduction in the risk of respiratory tract infections. This approach can be especially beneficial in the winter months when sunlight, a natural source of vitamin D, is scarce.

  • Caution in Mega-Dosing
  • However, a word of caution is warranted. Mega-dosing with vitamin D, defined here as daily doses ranging from 5,000 to 20,000 IU, can push vitamin D levels to excess, increasing the risk of respiratory infections. It is essential to strike a balance.

Timing Matters – Daily vs. Intermittent Supplementation

Moreover, the timing and frequency of supplementation play a vital role. Daily doses of vitamin D, such as 1,000 to 3,000 IU, have proven to be significantly more effective at enhancing immune function than infrequent, high-dose regimens, such as weekly, monthly, or every three months. In fact, a sudden influx of vitamin D into the body can actually dampen immune responses.

  • Tailoring Vitamin D Intake
  • The takeaway message is clear: individualized vitamin D intake is key. Understanding your baseline vitamin D level is crucial. If it falls below the 75 nmol/L (30 ng/ml) threshold, consult your healthcare provider about an appropriate daily supplement regimen.

    Conversely, if your vitamin D levels have scaled the 140 nmol/L (56 ng/ml) peak, it may be wise to reassess your supplementation strategy, unless your specialist has prescribed this as part of managing an autoimmune condition.

  • Beyond Immunity – The Wider Implications of Vitamin D
  • While the focus here has been on the immune-boosting properties of vitamin D, its benefits extend far beyond respiratory health. Research continues to unveil its role in bone health, cardiovascular wellness, and even mental health.

Conclusion: A Bright Future with Vitamin D

The review article by Bergman et al. has illuminated the pivotal role of vitamin D in respiratory health. It has provided a roadmap for individuals to fortify their immune systems and reduce the risk of respiratory tract infections.

However, this journey is not without its pitfalls. Balance is key, and understanding one’s own vitamin D levels is the compass guiding us to that equilibrium.

So, as we move forward, let us take heed of this research and embrace the power of vitamin D, not as a mere supplement but as a shield against the invisible invaders that threaten our respiratory well-being.


  1. Bergman P, Lindh A, Bjorkhem-Bergman, Lindh J. Vitamin D and respiratory tract infections: A systemic review and meta-analysis of randomized controlled studies. *PLOS (peer-reviewed, open-access journal).* 2013; 8(6):e65835 [Link](

Eat Smart, Live Well, Look Great,

Dr. Meschino

Dr. James Meschino


Dr. James Meschino, DC, MS, ROHP, is an educator, author, and researcher having lectured to thousands of healthcare professionals across North America. He holds a Master’s Degree in Science with specialties in human nutrition and biology and is recognized as an expert in the field of nutrition, anti-aging, fitness, and wellness as well as the author of numerous books.

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