This article originally appeared on Focal Points and was republished with permission.
Guest post by Nicolas Hulscher, MPH
73.3% of myocarditis cases had low vitamin D—linked to higher inflammation, heart damage, and ICU admissions—while sufficient levels were associated with reduced severity.
The study titled, The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis, was just published in the journal Frontiers in Immunology:
Introduction: Vaccine-related myocarditis is recognized as a rare but important complication, especially after mass-scale mRNA COVID-19 vaccination. Knowledge regarding how to minimize the risk is limited. As NK cells can mediate acute myocarditis after mRNA COVID-19 vaccination and vitamin D may inhibit NK cells via cytokine modulation, we hypothesize that the myocarditis side effect is related to a hypovitaminosis D – mRNA vaccine – hypercytokinemia – NK cell axis, which is amendable to clinical intervention.
Methods: Biochemical, immunophenotypic and genotyping assays were performed to examine vitamin D status and immune profiles in 60 patients who had BNT162b2 vaccine-related acute myocarditis.
Results: A high incidence of hypovitaminosis D (73.3%) was observed in these individuals with vaccine-related myocarditis, particularly in those presented with chest pain or intensive care unit (ICU) admission. Moreover, vitamin D level was negatively associated with peak serum cardiac troponin T level during vaccine-related myocarditis. Genotypically, the GC (vitamin D binding protein) rs4588T allele which encoded the GC2 isoform of vitamin D binding protein was a risk allele, whereas the GC1S isoform was protective. Mechanistically, hypovitaminosis D was associated with higher levels of cytokines pivotal for natural killer (NK) cells (particularly interleukin-1β (IL-1β), IL-12, Interferon-γ (IFN-γ), and IL-8) and higher percentage of CD69+ NK cells in blood, which in turn correlated with chest pain presentation.
Conclusion: These data support the hypothesis that vitamin D plays a crucial role in mitigating mRNA vaccine-related myocarditis by modulating proinflammatory cytokine milieu and subsequent unfavorable NK cell activation, laying a groundwork for preventive and treatment strategies.
Key Findings:
Vitamin D Deficiency is Common in Myocarditis Cases
- 73.3% of individuals who developed myocarditis after mRNA injection had low vitamin D levels (≤50 nmol/L).
- Among those with vitamin D deficiency:
- 88.3% experienced chest pain, compared to those with normal vitamin D levels.
- 30% required ICU admission, indicating more severe cases.
Vitamin D May Reduce Risk
- Higher vitamin D levels were linked to:
- Lower inflammation in the heart (as indicated by lower cytokine levels).
- Reduced activation of NK cells (fewer CD69+ NK cells).
- Fewer severe symptoms of myocarditis (lower cTnT levels and fewer ICU admissions).
- Patients with vitamin D sufficiency (>50 nmol/L) were less likely to experience severe symptoms (p < 0.05).
Lower Vitamin D = More Heart Damage
- Patients with low vitamin D had higher levels of cardiac troponin T (cTnT), a marker of heart damage:
- Vitamin D-deficient patients had an average cTnT of 0.62 ± 0.40 ng/mL.
- Patients with sufficient vitamin D had significantly lower cTnT levels (p = 0.0099).
- Vitamin D levels were negatively correlated with cTnT (r = -0.3053, p = 0.0221).
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Nicolas Hulscher, MPH
Epidemiologist and Foundation Administrator, McCullough Foundation
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