The Irresponsible Use or Overdose of Vitamin Supplements in the Time of Covid-19 Pandemic

Abstract

Background: Rising fear of coronavirus disease 2019 (COVID 19) accelerated self medication with high dose vitamins worldwide. In the Philippines, marketing claims and unrestricted over the counter access intensified this trend, yet empirical data on magnitude and consequences are limited.

Methods: A nationwide, cross sectional, mixed methods study was conducted between July 2021 and March 2022. Adults ≥18 years were recruited through multistage cluster sampling of all regions. Data were gathered via interviewer administered questionnaires that captured socio demographics, supplement patterns before and during the pandemic, knowledge–attitude–practice (KAP) scores, and self reported adverse events. Serum 25 hydroxy vitamin D and creatinine were obtained from a 10 % subsample. Multivariate logistic regression identified predictors of overdose (daily intake > Upper Tolerable Intake Level for ≥30 days). Qualitative interviews with 30 purposively selected participants explored drivers of excessive use.

Results: Of 2 146 respondents (response rate = 91 %), pandemic era supplement use rose from 49 % to 77 % (p < 0.001). Vitamin C (70 %), D (55 %), and multivitamins (60 %) predominated (Figure 1). Overall, 31 % met criteria for overdose; 8 % reported at least one moderate or severe adverse event, the commonest being nephrolithiasis and hypercalcemia. Overdose correlated independently with misinformation exposure (adjusted odds ratio [aOR] 2.98, 95 % CI 2.22–4.01), high income (aOR 1.64, 95 % CI 1.20–2.25), and low KAP score (aOR 2.09, 95 % CI 1.55–2.82). Qualitative themes mirrored quantitative findings, highlighting social media influence and “immune boosting” narratives.

Conclusion: Unregulated high dose vitamin intake surged during COVID 19 in the Philippines, producing measurable clinical harm. Policies enforcing evidence based advertising, front of label risk warnings, and primary care led counselling are urgently warranted.