Exploring the Effects of Vitamin D and Vitamin A Levels on the Response to COVID-19 Vaccine

Abstract

COVID-19 vaccines were developed at an unprecedented speed in history. The factors affecting the response to COVID-19 vaccines are not clear. Herein, the effects of vitamin D and vitamin A (retinol) levels on the response to the BNT162b2 vaccine were explored. A total of 124 vaccine recipients were recruited from the general population attending vaccination centers in Irbid, Jordan. Blood samples were collected immediately before receiving the first vaccine dose (D0) and three weeks later (D21). Baseline (D0) levels of 25-hydroxyvitamin D [25(OH)D], retinol, and SARS-CoV-2 S1 IgG antibodies were measured with ELISA. The response to the BNT162b2 vaccine was tested by measuring the levels and avidity of SARS-CoV-2 S1 IgG antibodies on D21. The participants were divided into two groups, unexposed and exposed, based on the D0 SARS-CoV-2 antibody results. No significant correlation was found between the levels of 25(OH)D or retinol and the levels, avidity, or fold increase of antibodies in both groups. Similarly, no significant difference in antibody response was found between 25(OH)D status groups, retinol status groups, or combined status groups. These findings show that the baseline vitamin D or vitamin A levels have no effect on the short-term response to a single dose of BNT162b2 vaccine.

Keywords: COVID-19; immune response; vaccine; vitamin A; vitamin D.

Figure 1

Analyzing the effect of vitamin D levels on SARS-CoV-2 antibody response in unexposed individuals. (A,B) show the correlation analysis between baseline (D0) 25(OH)D levels and the D21 level (A) or avidity index (B) of SARS-CoV-2 S1 IgG antibodies. No significant correlations were found (p > 0.05). In (C,D), the unexposed participants were divided into three groups based on the D0 levels of 25(OH)D, and the mean D21 antibody levels (C) or avidity indices (D) were compared between the groups. No significant differences in the levels or avidity were found between the groups (p > 0.05, One-way ANOVA). ns: not significant.

Figure 2

Analyzing the effect of vitamin A levels on SARS-CoV-2 antibody response in unexposed individuals. (A,B) show the correlation analysis between baseline (D0) retinol levels and the D21 level (A) or avidity index (B) of SARS-CoV-2 S1 IgG antibodies. No significant correlations were found (p > 0.05). In (C,D), the unexposed participants were divided into three groups based on the D0 levels of retinol, and the mean D21 antibody levels (C) or avidity indices (D) were compared between the groups. No significant differences in the levels or avidity of the antibodies were found between the groups (p > 0.05, One-way ANOVA). ns: not significant.

Figure 3

Analyzing the effects of vitamin D and vitamin A on SARS-CoV-2 antibody response in previously exposed individuals. Correlation between baseline (D0) levels of 25(OH)D (A) or retinol (B) and log₂ folds of increase in SARS-CoV-2 S1 IgG antibody levels between D0 and D21 in previously exposed individuals. No significant correlation was found. In (C,D), exposed participants were dived into two groups of D0 25(OH)D levels (C) or two groups of D0 retinol levels (D). The means of log2 fold increase in SARS-CoV-2 S1 IgG antibody levels were compared between the groups. No significant difference in the antibody level increase was found between the groups (p > 0.05, t test). ns: not significant.

Figure 4

Analysis of the combined effect of vitamin D and vitamin A on the response to BNT162b2 vaccine. Unexposed participants were first divided into four groups based on the combined status of 25(OH)D and retinol. Then, the mean level (A) or avidity (B) of SARS-CoV-2 S1 IgG antibodies were compared between the four groups. No significant difference in the levels or avidity were found between the groups. ns: not significant.