Impact of Vitamin D3 Supplementation on COVID-19 Vaccine Response and Immunoglobulin G Antibodies in Deficient Women: A Randomized Controlled Trial

This small intervention study found that serum 25(OH)D was positively correlated with COVID-19 antibody levels in healthy females. 

• When compared to baseline levels, significantly higher COVID-19 IgG antibody levels were seen in the vitamin D group compared to the untreated control group over time.  
• A significant positive correlation was found between IgG antibody level and 25-hydroxy vitamin D levels at the end of the study period. 

33 healthy females with vitamin D deficiency who had received two doses of a COVID-19 vaccine.

• This study included a small number of participants, who were all within a small (relatively young) age range, so is not representative of the population in general. 
• The study authors found significant differences between the diets of the control and test subjects which may have contributed additional dietary vitamin D, making the results of vitamin D supplementation difficult to interpret.  

It was determined that serum IgG levels increased significantly depending on the duration between those who used vitamin D and those who did not and it was above the initial level for a long time. A positive and significant relationship was found between the last measured immunoglobulin G and 25(OH)D levels while vitamin D supplementation continued.

• This randomized controlled trial examined the effect of vitamin D supplementation on COVID-19 antibody levels after vaccination. 
• Female volunteers, aged 18-23, who had received two doses of a COVID-19 vaccine (Pfizer-BioNTech or Sinovac), with a mean duration of 65 days since the last vaccine dose, received 3200 IU of vitamin D per day for two months. The control group received no supplement. 
• Serum 25(OH)D and COVID-19 antibody levels were measured at the start of the study, and again at two intervals 28-days apart. 

Cesur F, Atasever Z, Özoran Y. Impact of vitamin D3 supplementation on COVID-19 vaccine response and immunoglobulin G antibodies in deficient women: A randomized controlled trial. Vaccine. 2023 Apr 24;41(17):2860-2867. doi: 10.1016/j.vaccine.2023.03.046.