Reply - Letter to the editor: "Micronutrient supplementation, COVID-19 vaccination and adverse effect".

Dear Editor,

The authors, Mungmunpuntipantip R & Wiwanitkit V, have highlighted the concerns of adverse effects of COVID vaccines in thalassemia [1]. We wish to highlight that data specific to the safety and efficacy of COVID-19 vaccines, in thalassemia patients is limited. However, there is significant data to show that COVID infection in thalassemia is associated with significant mortality (>25%) [2,3]. Hence, most international guidelines suggest that the benefits of COVID-19 immunization outweigh any theoretical risks of immunization [4].

With regards to genetic polymorphisms like vitamin D genetic polymorphisms, specific data on the safety and efficacy of COVID-19 vaccines, is limited. However, there is evidence to show that individuals with vitamin D genetic polymorphisms and other polymorphisms in the vitamin D metabolism pathway, are at increased risk for COVID-19 infection severity and mortality [5,6]. There is also evidence to show low pre-infection 25(OH)D concentrations is associated with increased risk of COVID-19 infection severity and mortality [7]. Hence, the benefits of COVID-19 immunization will outweigh any theoretical risks of immunization regardless of underlying vitamin D related genetic polymorphisms and vitamin D deficiency. Moreover, vitamin D supplementation to maintain adequate 25(OH)D concentrations has been suggested to reduce the risk of COVID-19 transmission and infection [8].

We wish to highlight that while we suggest that supplementation will be useful in susceptible patients to reduce the risk of adverse effects in terms of autoimmune re-activation and thrombosis potential with COVID-19 vaccinations, these adverse effects are relatively rare. Hence, we would like to stress on the importance of COVID-19 immunization in the population.

Author contributions

RD and BOB drafted and reviewed this reply. All authors attest they meet the ICMJE criteria for authorship.

Declaration of competing interest

The author declares no potential conflict of interest.