Association between COVID-19 vaccine side effects and history of nutritional supplement intake and body mass index (BMI): a retrospective study

Purpose As the development and vaccination of the COVID 19 vaccine is accelerating worldwide, it is important to investigate the ways to improve immunity and immune responses to vaccines. This study aims to investigate the association between history of nutritional supplements intake and body mass index (BMI) in the severity of COVID-19 vaccine side effects after vaccination. Design/methodology/approach A total of 465 vaccinated participants with the Sinopharm vaccine (females and males in the 18–65 age range) participated in the study. Anthropometric measurements were taken on the first visit. In addition, nutrient supplement history and demographic information were collected. Moreover, the participants’ phone numbers were collected and they were contacted. Participants were asked to report if they experienced systemic (whole-body) and/or local side effects after vaccination, in the following eight days. Then, participants were grouped into four categories: no symptoms (n = 232), mild symptoms (n = 121), moderate symptoms (n = 55) and severe symptoms (n = 57). Findings There was a significant difference between the consumption of nutritional supplements by different groups of participants in the last six months (considering the severity of the symptoms) (p < 0.001). The odds ratio (OR) and 95% confidence intervals (CI) for the incidence of side effects from the COVID-19 vaccine increased in the Q3 of BMI (range 22.94–26.34) in Modes 2 and 3: [OR: 1.85, (95% CI: 1.14– 3.00), p-for trend = 0.08] and [OR: 1.89, (95% CI: 1.16– 3.09), p-for trend = 0.09] based on logistic regression models. Originality/value In this study, the history of nutrient supplement intake affects the severity of side effects after the vaccination with COVID-19. Furthermore, based on logistic regression models, side effects were more prevalent in the BMI range 22.9–26.3 when compared to BMI < 20.2 so further study is necessary.