Abstract
Background
While numerous studies evaluated dietary supplement use during the acute phases of the COVID-19 pandemic, evidence regarding health behavioral changes remains scarce, particularly in the Middle East. This study provides a comprehensive evaluation of self-reported changes in dietary supplement consumption patterns before and years after the pandemic in Jordan, in a region where evidence on post-pandemic supplement use is limited.
Methods
A cross-sectional study was conducted in Jordan (from June to August 2025) among 427 participants, with pre-pandemic dietary supplement use assessed retrospectively through participant self-report. Wilcoxon signed-rank test and McNemar’s test were used for paired analyses. Multivariable ordinal logistic regression was applied to identify predictors of changes in use.
Results
Significant increases in the use of most dietary supplements were observed in the post-pandemic era (q < 0.05), with the exception of herbal supplements. Nearly half of the participants (49.2%) reported a sustained increase in dietary supplement use. Daily consumption rose sharply from 6.6% pre-pandemic to 31.4%, while non-use declined from 16.2% to 11.0% (p < 0.001). The perceived importance of supplements for ongoing health maintenance surged, with “very important” responses rising from 17.3% to 59.5% (p < 0.001). Heightened health awareness was the most frequently reported reason for maintaining or increasing intake (71.0%). Multivariable ordinal logistic regression showed that baseline pre-pandemic supplement-use frequency, recruitment mode and COVID-19 infection severity were significantly associated with changes in supplement consumption.
Conclusion
Changes in dietary supplement use in Jordan were observed after the pandemic, including a shift toward frequent and daily consumption. These findings suggest that changes in supplement-use behaviors remained evident in the post-pandemic period. The growing perceived value of dietary supplements underscores need for evidence-based public health guidance to promote safe and rational supplement use in the post-pandemic era.
Keywords: dietary supplements, COVID-19, Jordan, health behavior, health perception
Introduction
Dietary supplements, particularly vitamins and minerals, are widely used for health maintenance and disease prevention.1 Dietary supplements such as vitamin D, vitamin C, and zinc have been widely used to enhance immune responses during common respiratory infections,2 while deficiencies in these micronutrients have been linked to increased susceptibility to infections.3,4 However, evidence regarding their effectiveness in treating or preventing specific infections, such as coronavirus disease 2019 (COVID-19), remains insufficient.5
The public interest in dietary supplement consumption surged globally during the COVID-19 pandemic, motivated by health concerns, fear of infection and the desire to prevent illness.6 Dietary Supplements such as zinc, vitamins C and D, and omega-3 fatty acids gained attention during COVID-19 because of their potential roles in supporting immune function and regulating inflammation.7,8
Jordan confirmed its first case of COVID-19 in March 2020; this marked an important turn in its public health strategies implemented during the outbreak.9 The Jordanian government implemented several preventive measures, such as nationwide lockdowns, movement restrictions, and obligatory social distancing protocols.9 In parallel with these preventive measures, many people turned to utilize dietary supplements and herbal products, believing that these products could minimize the severity of symptoms or prevent infection, particularly during the early phases of the outbreak when effective treatment options were limited.10,11
Several studies have examined dietary supplement use during the acute phase of the COVID-19 pandemic.12,13 A Turkish study, for example, reported an increase in nutritional supplement consumption in response to COVID-19, even though participants’ eating habits did not significantly change.14 Another Saudi Arabian study, conducted during the acute phase, found that the frequency of supplement intake was higher than before the pandemic period.13 These studies captured behaviors during the acute phase, without answering the major question: did these behaviors disappear once COVID-19 subsided?
To address this gap, our current research comprehensively evaluates self-reported changes in supplement intake across both pre- and post-pandemic periods within the same population in Jordan- a country where comparative evidence on behavioral adaptations remains scarce. We believe this is among the first retrospective pre-post studies to investigate the changes in these health habits and perceptions years after the initial outbreak. Understanding these post-pandemic patterns is also important from a public health perspective, as changes in supplement use may have implications for health education, risk communication, and guidance on appropriate supplement use.
Therefore, our study aims to assess changes in the frequency and patterns of dietary supplement use before versus after the COVID-19 pandemic in Jordan, examine participants’ reported reasons for changes in consumption, determine predictors of these changes, and examine public perceptions regarding the importance of dietary supplements for health maintenance.
Materials and Methods
Study Design and Data Collection
This study is part of a large cross-sectional survey created to assess the use of both natural products and dietary supplements in Jordan in both pre- and post-COVID-19 pandemic periods. It was carried out in Jordan from June to August 2025. Data generated from the examination of natural product use have been reported in separated manuscript, whereas this manuscript focuses on the analysis of the data related to the use of dietary supplements.
A total of 427 male and female participants aged 18 years and older, from multiple governorates across Jordan, were included in this survey. They were recruited using either an online structured survey link or face-to-face distribution to maximize population coverage. For online recruitment, the questionnaire link was distributed through WhatsApp and Facebook and was not restricted to university or health-related networks. To minimize duplicate online submissions, the survey was configured to permit only one response per Email account. For face-to-face recruitment, eligible adults were directly approached by members of the research team in public plazas and community centers. The research team distributed the questionnaires and collected the completed forms. No financial or other incentives were provided for participation.
A total of 203 complete questionnaires were received through online recruitment. The total number of individuals who viewed or accessed the online invitation could not be determined. Only questionnaires submitted by clicking the final “Submit” button were recorded in the database; incomplete or unsubmitted responses were not captured. Therefore, the number of individuals who started but did not submit the questionnaire was unavailable, and an online response rate could not be calculated. For face-to-face recruitment, approximately 258 individuals were approached, of whom 224 completed the questionnaire, and 34 did not complete it, corresponding to a completion rate of approximately 86.8%. The final analytical sample comprised 427 completed questionnaires. Only fully completed questionnaires were included in the final analysis; incomplete questionnaires were excluded, and therefore no missing-data imputation was required.
Ethical Considerations and Consent to Participate
The study protocol was reviewed and approved by the Research Ethics Committee at Al al-Bayt University (Reference No.: IRB_AABU_8). Participation was voluntary, and consent was implied through the submission of the questionnaire. All collected data were handled with strict confidentiality and used solely for research purposes.
Sample Size Determination
The sample size was calculated using Cochran’s formula for large populations (approximately 11,850,000),15 with a confidence level of 95% (Z = 1.96), an estimated proportion (p) of 0.5, and a margin of error (e) of 0.05, yielding a minimum required sample size of 385 participants. Given the large population size (n ≈ 11,850,000), the application of the finite population correction did not substantially alter the estimated sample size. The calculated sample size was increased by 10% to compensate for possible non-response,16,17 resulting in a final target of approximately 424 participants (385 × 1.10 = 423.5). Accordingly, the final sample size was set at 427 participants. The sample-size calculation was designed to address adequate precision for estimating population proportions in the cross-sectional survey and was not specifically designed around the paired comparisons or multivariable ordinal logistic regression analyses.
Questionnaire Development and Validation
The questionnaire was initially developed in English based on a comprehensive review of previously published questionnaire-based studies.2,18,19 It subsequently underwent a two-stage validation process involving expert panels. The first panel consisted of four medical experts who critically assessed and face-validated the questionnaire for clarity, relevance, and comprehensiveness. Based on their feedback, the questionnaire items were revised accordingly. The second panel of five medical experts evaluated the content validity, resulting in a scale-level content validity index (S-CVI/Ave) of 0.86, indicating satisfactory content validity of the instrument.
In addition, forward and backward translation were performed by bilingual medical and non-medical professionals to ensure that all items were accurately translated without alteration of meaning or mistranslation. The final Arabic version of the questionnaire was subjected to a pilot test (n = 40) to assess the clarity, feasibility, and reliability of the items from the participants’ perspective before large-scale distribution.
The final version of the questionnaire consisted of five main sections. Items in the first section covered sociodemographic parameters, including nationality, age, gender, region of residence in Jordan, education level, and employment status. Items in the second section addressed participants’ medical history, including the presence of chronic diseases, previous COVID-19 infection and its severity level, as well as COVID-19 vaccination status. Items in the third section examined dietary supplement use before the COVID-19 pandemic period, including the types of dietary supplements used, reasons for using dietary supplements and patterns of use. Items in the fourth part examined dietary supplement use after the COVID-19 pandemic, including types of supplements used, changes in consumption, factors influencing changes in use, and usage patterns. Items in the fifth part measured the perceived importance of dietary supplement use before and after the COVID-19 pandemic. Finally, the questionnaire included open-ended items to capture the participants’ suggestions and their interest in receiving further information or guidance regarding dietary supplement use. For the purposes of this study, at the beginning of the questionnaire, participants were instructed to consider the pre-pandemic period as the period before late December 2019, focusing primarily on the preceding 2–3 years, and the post-pandemic period as the period after May 2023, when the World Health Organization (WHO) ended COVID-19’s designation as a Public Health Emergency of International Concern. These temporal reference points were specified in the survey instructions.
Statistical Analysis
All data were analyzed using IBM SPSS Statistics for Windows, Version 22.0 (IBM Corp., Armonk, NY, USA). Categorical variables were analyzed as percentages. Differences in paired binary responses (pre- vs post-COVID-19 pandemic) were assessed using McNemar’s test; the paired odds ratio (OR) and its 95% confidence interval (CI) were calculated from the discordant pairs using the standard log(OR) method, as previously described.20,21 The Benjamini-Hochberg false discovery rate (FDR) correction was applied to the unrounded exact McNemar’s p- values to control for multiple testing; adjusted p-values (q-values) less than 0.05 were considered significant.
Multivariable ordinal logistic regression was performed to assess associations between changes in dietary supplement use and relevant predictors. The change in supplement use was coded as 1 = increased use, 2 = no change, and 3 = decreased use, with higher values correlating with decreased supplement use. Variables included in the multivariable ordinal logistic regression model were selected based on their relevance to the study objectives and their potential association with dietary supplement-use behavior. The model included age, gender, education level, employment status, region of residence, chronic illness, COVID-19 infection severity, COVID-19 vaccination status, recruitment mode, and baseline pre-pandemic supplement-use frequency. Age groups 40–59 years and ≥60 years were combined into a single ≥ 40 years category, moderate and severe COVID-19 infection were combined into a single moderate-to-severe category, and retired medical- and non-medical-sector participants were combined into a single retired category to ensure sufficient sample sizes and stable parameter estimates. Baseline supplement-use frequency was entered as an ordinal covariate, coded from 1 = daily to 5 = never. The proportional odds assumption for the ordinal logistic regression model was evaluated using the test of parallel lines. Model fit was assessed using Pearson and Deviance goodness-of-fit statistics. Recruitment mode was included as a categorical predictor in the multivariable ordinal regression model to examine potential differences by recruitment mode (online versus face-to-face). Changes in the perceived importance of dietary supplements and patterns of dietary supplement use before and after the COVID-19 pandemic were assessed using the Wilcoxon signed-rank test. A p-value less than 0.05 was considered statistically significant.
Results
Sociodemographic and Health Features of the Participants
A total of 427 respondents from different governorates across Jordan were recruited for this cross-sectional study. The majority of participants (65.1%, n = 278/427) were female and younger than 40 years (72.8%, n = 311/427). Participants had relatively high academic attainment, with 54.6% (n = 233/427) holding a bachelor’s degree. Regarding health-related characteristics, 21.8% (n = 93/427) of respondents indicated having at least one chronic disease. Over half of the participants (61.6%, n = 263/427) reported a previous COVID-19 infection. Coverage of COVID-19 vaccination was high (82.7%, n = 353/427). Detailed sociodemographic and health features are outlined in Table 1.
Table 1.
Sociodemographic and Health Features of the Study Population (n = 427)
| Characteristic | n (%)a |
|---|---|
| Nationality | |
| Jordanian | 411 (96.3) |
| Non-Jordanian | 16 (3.7) |
| Region of residence | |
| Northern Jordan | 299 (70.0) |
| Central Jordan | 108 (25.3) |
| Southern Jordan | 20 (4.7) |
| Gender | |
| Male | 149 (34.9) |
| Female | 278 (65.1) |
| Age group (years) | |
| 18–24 | 143 (33.5) |
| 25–39 | 168 (39.3) |
| 40–59 | 85 (19.9) |
| ≥60 | 31 (7.3) |
| Education level | |
| Less than high school | 31 (7.3) |
| High school | 58 (13.6) |
| Diploma | 32 (7.5) |
| Bachelor’s degree | 233 (54.6) |
| Postgraduate | 73 (17.1) |
| Occupation | |
| Student | 128 (30.0) |
| Unemployed | 94 (22.0) |
| Medical sector employee | 69 (16.2) |
| Non-medical sector employee | 80 (18.7) |
| Self-employed | 28 (6.6) |
| Retired from medical sector | 8 (1.9) |
| Retired from non-medical sector | 20 (4.7) |
| Chronic disease | |
| No | 334 (78.2) |
| Yes | 93 (21.8) |
| COVID-19 infection severity | |
| Never infected | 164 (38.4) |
| Mild | 129 (30.2) |
| Moderate | 112 (26.2) |
| Severe | 22 (5.2) |
| COVID-19 vaccination | |
| No | 74 (17.3) |
| Yes | 353 (82.7) |
Note: aData are presented as numbers (n) and percentages (%).
Frequency of Dietary Supplement Use Before the COVID-19 Pandemic
Before the COVID-19 outbreak, vitamin C was the most frequently used supplement (n = 179/427, 41.9%), followed by vitamin D (n = 155/427, 36.3%) and vitamin B12 (n = 140/427, 32.8%). The lowest frequency was reported for vitamin B9 (n = 27/427, 6.3%). The frequencies for all supplements are presented in Figure 1.
Figure 1.
Frequency of self-reported dietary supplement use before and after the COVID-19 pandemic among participants in Jordan (n = 427). Bars represent the percentage of participants reporting the use of each dietary supplement before and after the pandemic. The values presented in the table below the chart indicate the corresponding percentages and the net percentage-point change (pp) between the two periods. Overall, a significant increase in the use of dietary supplements was observed following the COVID-19 pandemic for all categories except herbal supplements. Asterisk (*) above the “After” (Orange) bar indicates a statistically significant difference between the pre- and post-pandemic periods based on McNemar’s test (p < 0.05).
Abbreviations: Vit., vitamin; HS, herbal supplements; Mg, magnesium; Ca, calcium; Zn, zinc.
The reasons underlying dietary supplement use before the pandemic were also examined. Increased awareness of personal health was the most frequently reported reason, indicated by 59.0% of participants. This was followed by the use of supplements to treat specific health conditions (38.2%). Other reported reasons are outlined in Table 2.
Table 2.
Reasons for Dietary Supplement Use Before the COVID-19 Pandemic (n = 427)
| Reason | n (%)a |
|---|---|
| Increased awareness of personal health | 252 (59.0%) |
| Treat specific health conditions | 163 (38.2%) |
| Family or cultural habits | 72 (16.9%) |
| Alternative to medical drugs | 54 (12.6%) |
Note: a Participants could select multiple reasons, so total percentages exceed 100%.
Frequency of Dietary Supplement Use After the COVID-19 Pandemic and Pre–Post Comparisons
After the COVID-19 pandemic, vitamin D became the most commonly used supplement (n = 230/427, 53.9%), closely followed by vitamin C (n = 214/427, 50.1%). Similar usage rates were observed for vitamin B12 and iron (n = 173/427 for each, 40.5% each). Vitamin B9 remained the least commonly used supplement (n = 47/427, 11.0%). A marked rise in the use of nearly all dietary supplements was detected following the pandemic. The largest increase was noted for vitamin D (+ 17.6 percentage points, pp) and magnesium (+ 12.7 pp), whereas herbal supplements showed the smallest change (+ 2.4 pp). The frequencies and percentage-point changes for all supplements are presented in Figure 1.
McNemar’s test confirmed that the increases in the consumption of several supplements after the COVID-19 pandemic were statistically significant among the study population. Following adjustment for multiple comparisons using the Benjamini–Hochberg FDR method, significant increases were observed for vitamin C, vitamin B12, vitamin D, magnesium, iron, zinc, calcium, omega-3 supplements, and vitamin B9 (all q < 0.05). In contrast, the change in the use of herbal supplements was not statistically significant (q = 0.228). Detailed results are provided in Table 3.
Table 3.
Changes in Dietary Supplement Use Before and After the COVID-19 Pandemic (n = 427)
| Supplement | Before % | After % | No→Yes | Yes→No | Net Δ (pp) | Paired OR (95% CI) | Exact McNemar p | BH-FDR q | Interpretation |
|---|---|---|---|---|---|---|---|---|---|
| Vitamin D | 36.3 | 53.9 | 90 | 15 | +17.6 | 6.00 (3.47–10.36) | 3.276×10−14 | 3.276×10−13 | Significant increase |
| Vitamin C | 41.9 | 50.1 | 63 | 28 | +8.2 | 2.25 (1.44–3.51) | 0.000313 | 0.000447 | Significant increase |
| Vitamin B12 | 32.8 | 40.5 | 62 | 28 | +7.7 | 2.21 (1.42–3.46) | 0.000438 | 0.000547 | Significant increase |
| Iron | 32.1 | 40.5 | 61 | 25 | +8.4 | 2.44 (1.53–3.89) | 0.000130 | 0.000261 | Significant increase |
| Magnesium | 13.3 | 26.0 | 64 | 10 | +12.7 | 6.40 (3.29–12.46) | 8.957×10−11 | 4.479×10−10 | Significant increase |
| Zinc | 13.3 | 20.8 | 43 | 11 | +7.5 | 3.91 (2.02–7.58) | 0.000014 | 0.000035 | Significant increase |
| Calcium | 11.9 | 21.3 | 49 | 9 | +9.4 | 5.44 (2.67–11.08) | 8.959×10−8 | 2.986×10−7 | Significant increase |
| Omega-3 | 24.4 | 32.8 | 62 | 26 | +8.4 | 2.38 (1.51–3.77) | 0.000157 | 0.000262 | Significant increase |
| Vitamin B9 | 6.3 | 11.0 | 27 | 7 | +4.7 | 3.86 (1.68–8.86) | 0.000821 | 0.000913 | Significant increase |
| Herbal Supplements | 31.6 | 34.0 | 40 | 29 | +2.4 | 1.38 (0.86–2.22) | 0.228400 | 0.228400 | Not significant |
Notes: Percentages represent the proportion of participants reporting supplement use in each period. Discordant pairs are presented as No→Yes and Yes→No. Net change (Δ) is expressed in percentage points (pp). Paired odds ratios (ORs) were calculated from discordant pairs. Statistical significance was assessed using McNemar’s test, and p-values were adjusted using the Benjamini–Hochberg false discovery rate (BH-FDR). q-values < 0.05 were considered statistically significant.
Abbreviations: OR, odds ratio; FDR, false discovery rate; pp, percentage points.
Patterns of Supplement Use Before and After the COVID-19 Pandemic
Before the COVID-19 pandemic, weekly use of dietary supplements was the most frequent pattern (n = 135/427, 31.6%), while only 6.6% (n = 26/427) of participants used them on a regular daily basis. Following the COVID-19 pandemic, a clear shift toward more frequent use was observed. Daily use increased markedly to 31.4% (n = 134/427), while weekly use remained relatively stable at 32.1% (n = 137/427). The distribution of the remaining frequency categories before and after the pandemic is presented in Figure 2. The Wilcoxon signed-rank test confirmed a statistically significant shift toward more frequent dietary supplement use after the COVID-19 pandemic (Z = −9.64, p < 0.001, r = 0.47).
Figure 2.
Patterns of dietary supplement use before and after the COVID-19 pandemic (n = 427). Bars represent the percentage of participants in each usage category. A shift toward more frequent use was observed, characterized by an increase in daily use, relatively stable weekly use, and a reduction in less frequent use (monthly and yearly) and never use following the pandemic. The overall shift toward more frequent use post-pandemic was statistically significant based on Wilcoxon signed-rank test (p < 0.001).
Changes in Dietary Supplement Use and Associated Factors Following the COVID-19 Pandemic
Overall Changes in Dietary Supplement Use
As presented in Table 4, overall, 258 out of 427 participants (60.4%) reported a change in dietary supplement use following the COVID-19 outbreak, either a decrease or an increase. Specifically, 49.2% (n = 210/427) of participants reported an increase in dietary supplement use, while 11.2% (n = 48/427) reported a decrease. Whereas, approximately 39.6% of participants (n = 169/427) reported no change in their supplement intake.
Table 4.
Changes in Dietary Supplement Use After the COVID-19 Pandemic and Participants’ Reported Reasons for Increased, Maintained, or Decreased Use
| Variables | Categories | n (%) |
|---|---|---|
| Change in supplement use after the COVID-19 pandemic (n = 427) | ||
| Increased use | 210/427 (49.2) | |
| Unchanged use | 169/427 (39.6) | |
| Decreased use | 48/427 (11.2) | |
| What were the main reasons for increased or maintained supplement use after COVID-19? (n = 379)a | ||
| Increased awareness of health maintenance | 269/379 (71.0) | |
| Supplements became more readily available after COVID-19 | 44/379 (11.6) | |
| Social influence | 48/379 (12.7) | |
| Family influence | 100/379 (26.4) | |
| Advice from healthcare professionals | 105/379 (27.7) | |
| What were the main reasons for decreased supplement use after the COVID-19 pandemic? (n = 48)a | ||
| High cost | 12/48 (25.0) | |
| Limited availability or access | 4/48 (8.3) | |
| Safety concerns | 14/48 (29.2) | |
| No perceived need after the pandemic | 8/48 (16.7) | |
| Lack of knowledge about proper use | 19/48 (39.6) |
Notes: a Participants could select multiple reasons; therefore, percentages may exceed 100%. Responses represent participants’ self-reported reasons and should not be interpreted as independently measured causal factors.
Self-Reported Reasons for Increased or Stable Dietary Supplement Use
Several reasons were reported for increased or stable dietary supplement use after the COVID-19 pandemic. Increased awareness of personal health was the most frequently reported reason (n = 269 /379, 71.0%). This was followed by guidance from healthcare professionals (n = 105/379, 27.7%) and influence from family members (n = 100/379, 26.4%). Other reported reasons are outlined in Table 4.
Self-Reported Reasons for Decreased Dietary Supplement Use
Among the 48 participants who reported decreased supplement use after the COVID-19 pandemic, the most frequently reported reason was lack of knowledge about proper use (n = 19/48, 39.6%), followed by safety concerns (n = 14/48, 29.2%) and high cost (n = 12/48, 25.0%). Other reported reasons are presented in Table 4.
Predictors of Changes in Dietary Supplement Use Following the COVID-19 Pandemic
Multivariable ordinal logistic regression was carried out to identify factors associated with changes in dietary supplement use following the COVID-19 pandemic (Table 5). The overall model was statistically significant (χ2 = 62.399, df = 20, p < 0.001). The proportional odds assumption was satisfied (test of parallel lines: χ2 = 26.303, df = 20, p = 0.156), and goodness-of-fit statistics indicated adequate model fit (Pearson χ2 = 774.705, df = 754, p = 0.293; Deviance χ2 = 693.586, df = 754, p = 0.943).
Table 5.
Multivariable Ordinal Logistic Regression Analysis of Factors Associated with Changes in Dietary Supplement Use Following the COVID-19 Pandemic (n = 427)
| Predictor | aOR | 95% CI | p-value |
|---|---|---|---|
| Baseline pre-pandemic supplement-use frequency | 0.70 | 0.59–0.83 | <0.001 |
| Recruitment mode | |||
| Face-to-Face | 1.83 | 1.17–2.85 | 0.008 |
| Online link | Ref. | ||
| Age group | |||
| 18–24 years | 0.81 | 0.37–1.79 | 0.603 |
| 25–39 years | 0.63 | 0.35–1.12 | 0.114 |
| ≥40 years | Ref. | — | — |
| Gender | |||
| Male | 1.32 | 0.84–2.07 | 0.237 |
| Female | Ref. | — | — |
| Education level | |||
| Less than high school | 1.83 | 0.72–4.66 | 0.206 |
| High school | 1.96 | 0.91–4.24 | 0.085 |
| Diploma | 1.59 | 0.64–3.90 | 0.315 |
| Bachelor | 1.74 | 0.97–3.14 | 0.063 |
| Postgraduate | Ref. | — | — |
| Employment status | |||
| Student | 0.58 | 0.20–1.67 | 0.310 |
| Unemployed | 0.55 | 0.22–1.40 | 0.212 |
| Self-employed | 1.01 | 0.35–2.90 | 0.981 |
| Medical-sector employee | 0.65 | 0.25–1.66 | 0.363 |
| Non-medical-sector employee | 0.43 | 0.17–1.09 | 0.075 |
| Retired | Ref. | — | — |
| Region of residence | |||
| Central | 0.90 | 0.35–2.32 | 0.826 |
| North | 0.69 | 0.28–1.72 | 0.429 |
| South | Ref. | — | — |
| Chronic illness | |||
| No | 1.37 | 0.81–2.30 | 0.239 |
| Yes | Ref. | — | — |
| COVID-19 infection severity | |||
| Never infected | 3.02 | 1.83–4.97 | <0.001 |
| Mild | 1.71 | 1.02–2.86 | 0.040 |
| Moderate-to-severe | Ref. | — | — |
| COVID-19 vaccination | |||
| No | 0.64 | 0.37–1.11 | 0.113 |
| Yes | Ref. | — | — |
Notes: Reference categories: online recruitment; age ≥40 years; female gender; postgraduate education; retired employment status; Southern region; having a chronic illness (yes); moderate-to-severe COVID-19 infection; and COVID-19 vaccination (yes). Baseline pre-pandemic supplement-use frequency was entered as an ordinal predictor; higher scores indicate less frequent supplement use. The aOR represents the change in odds per one-category increase in the frequency score. Bold values indicate statistical significance (p < 0.05). The proportional odds assumption was satisfied (Test of Parallel Lines, p = 0.156). The ordinal outcome was ordered from increased to unchanged to decreased supplement use; therefore, aOR >1 indicates higher odds of being in the direction of unchanged/decreased use.
Abbreviations: aOR, adjusted odds ratio; CI, confidence interval; Ref., reference category.
As shown in Table 5, among the variables examined, Baseline pre-pandemic supplement-use frequency, recruitment mode and COVID-19 infection severity were independently associated with changes in supplement use. Higher baseline-frequency scores, representing less frequent pre-pandemic use, were associated with lower odds of being in a higher outcome category (aOR = 0.70, 95% CI: 0.59–0.83, p < 0.001). Compared with participants who had experienced moderate-to-severe COVID-19 infection, those who had never been infected had higher odds of being in a higher outcome category (aOR = 3.02, 95% CI: 1.83–4.97, p < 0.001), as did those who had experienced mild infection (aOR = 1.71, 95% CI: 1.02–2.86, p = 0.040). This indicates that participants with moderate-to-severe infection were more likely to report increased supplement use. Meaning that participants who experienced moderate-to-severe COVID-19 infection have a greater tendency toward increased supplement use compared with those who were never infected or experienced mild infection. Recruitment mode was also significantly associated with the outcome; face-to-face participants had higher odds of being in a higher outcome category than online participants (aOR = 1.83, 95% CI: 1.17–2.85, p = 0.008), corresponding to a shift toward unchanged or decreased supplement use. Age, gender, education level, employment status, region of residence, chronic illness, and vaccination status were not significantly associated with changes in dietary supplement use (all p > 0.05).
Changes in Perceived Importance of Dietary Supplement Use Following the COVID-19 Pandemic
Prior to the COVID-19 pandemic, the majority of participants perceived dietary supplement consumption as “moderately important” (56.4%, n = 241/427), while a smaller proportion considered it “very important” (17.3%, n = 74/427). After the pandemic, a notable shift toward higher perceived importance occurred. The proportion of participants reporting dietary supplement use as “very important” increased markedly to 59.5% (n = 254/427), while those rating it as “moderately important” decreased to 33.7% (n = 144/427). The distribution of the remaining categories before and after the pandemic is presented in Figure 3. This shift toward higher perceived importance of dietary supplement use after the COVID-19 pandemic was statistically significant, as confirmed by the Wilcoxon signed-rank test (Z = −12.84, p < 0.001, r = 0.62).
Figure 3.
Perceived importance of dietary supplement use before and after the COVID-19 pandemic (n = 427). The lines represent the percentage of participants in each perceived importance category. Following the COVID-19 pandemic, a marked shift toward greater perceived importance of dietary supplements was observed, characterized by an increase in the proportion of participants rating supplements as “very important” and corresponding decreases in the lower importance categories. This overall shift toward a higher perceived importance category was statistically significant, as confirmed by the Wilcoxon signed-rank test (p < 0.001).
Discussion
In this cross-sectional study, we examined changes in dietary supplement use in Jordan across the pre- and post-COVID-19 pandemic periods. Following the pandemic, an increased reliance on supplements, a shift toward daily intake, and an increased perceived importance of supplementation were detected. Together, these results suggest that changes in dietary supplement use behaviors, attitudes, as well as perceptions remained evident in Jordan during the post-pandemic period and may reflect a greater emphasis on immune health and preventive health measures after the COVID-19 pandemic had ended. This study also identified knowledge gaps regarding the appropriate use of dietary supplements, together with safety concerns, highlighting the need for clearer public guidance on how to use these products appropriately and safely.
The study showed that the post-pandemic period was characterized by a significant increase in the intake of vitamin D and vitamin C, along with notable increases in magnesium, zinc, omega-3 supplements, vitamin B12, iron, calcium, and vitamin B9 consumption (all q < 0.05). This increased reliance on these products likely reflects a shift toward more preventive, immunity-focused behavior driven by their perceived roles in supporting immune function. For example, vitamin D gained considerable attention during COVID-19 infection for its immunomodulatory role in both adaptive and innate immunity.22 Interestingly, while participants increased use of these products for health maintenance and infection prevention, clinical evidence regarding the effectiveness of dietary supplements in protecting against COVID-19 infection remains limited.23
This observed post-pandemic increase in dietary supplement consumption mirrors behavioural adaptations documented in prior research conducted during the pandemic period. In Jordan, several studies reported an increase in dietary supplement consumption as a short-term response to COVID-19 infection.24–26 Also, this result was consistent with studies conducted in neighbouring countries; for example, a Saudi Arabian study showed an increase in vitamin C, zinc, and multivitamins intake in response to COVID-19 infection.13 A multinational Middle Eastern study found that approximately 44% of participants changed their dietary supplement use during the COVID-19 pandemic.27 Globally, a similar pattern was observed; for instance, an Irish study documented an increase in vitamin D levels during the first year of the pandemic.28 Critically, these prior studies captured use during the active phase of the COVID-19 pandemic, while our findings revealed that this increase in supplement use was still observed several years after the acute pandemic subsided.
On the other hand, the current study showed a slight, non-significant change in using herbal supplements (31.6% before vs 34.0% after, q = 0.228). This observation may be explained by several reasons: 1) public awareness of their potential role in immune support may be lower compared with well-known micronutrients such as vitamin D and C; 2) cultural preferences in Jordan may favor consuming herbal products in their traditional forms (raw or home-made herbal remedies) rather than standardized commercial products; and 3) cost as home-prepared herbal remedies are typically less expensive than standardized herbal preparations. Commercial herbal supplements require a series of steps in formulation, standardization, and evaluation of quality before marketing, which complicates their production.29 This finding is in agreement with a recent systematic review showing that the adoption of herbal supplements during the COVID-19 pandemic was less consistent than that of vitamin/mineral supplements across different populations.30
Besides increased consumption, we also found a significant shift from occasional use toward daily use (p < 0.001). Daily use increased markedly from 6.6% before the pandemic to 31.4% after the pandemic. Participants who reported monthly, yearly, and non-users declined in the post-pandemic period. Previous studies documented similar trends, reporting more frequent use and regularity of dietary supplement intake during the COVID-19 pandemic period.31,32 Increased awareness of health maintenance was the most frequently cited reason for increased or maintained supplement use (reported by 71.0%). This is in agreement with previous research demonstrating that the adoption of healthier behaviors often occurs in response to health risks.33,34 Similarly, other earlier studies indicated that changes in supplement consumption were changed based on public perceptions of health threats and individual health beliefs.35,36
The multivariable regression analysis identified baseline pre-pandemic supplement-use frequency, recruitment mode, and COVID-19 infection severity as significant predictors associated with these behavioral changes in the post-pandemic era. Participants who had mild COVID-19 infection (aOR = 1.71, 95% CI: 1.02–2.86, p = 0.040) or had never been infected (aOR = 3.02, 95% CI: 1.83–4.97, p < 0.001) showed a greater tendency toward unchanged or decreased supplement use relative to those with moderate-to-severe infection. This finding suggests that individuals who experienced moderate to severe illness may have become more motivated to adopt health-promoting behaviors, including increased dietary supplement use, following their infection. Similar observations have been reported in previous acute-phase studies, which reported increased use of vitamins, minerals, and other dietary supplements among individuals who perceived themselves to be at higher risk of infection or who had experienced more severe COVID-19 symptoms.2,31 Baseline pre-pandemic supplement-use frequency was also associated with subsequent changes in use (aOR = 0.70, 95% CI: 0.59–0.83, p < 0.001), highlighting the importance of accounting for previous supplement-use patterns when evaluating post-pandemic behavioral changes.
Recruitment mode was also associated with changes in supplement use, with face-to-face participants showing higher odds of being in a higher outcome category than online participants (aOR = 1.83, 95% CI: 1.17–2.85, p = 0.008). This finding suggests that differences related to recruitment mode may have influenced the observed response patterns and should be considered when interpreting the reported changes. While the combined online and face-to-face approach may have broadened participation, potential mode-related differences in responses cannot be excluded. In contrast, age, gender, education level, employment status, region of residence, chronic illness status, and vaccination status were not significantly associated with changes in dietary supplement use (all p > 0.05).
On the other hand, approximately 11.2% of participants reported a post-pandemic decrease in supplement use. Lack of knowledge regarding proper supplement use was the most cited reason (39.6%), suggesting that uncertainty and health misinformation may play a role in decisions regarding continued dietary supplement consumption after the pandemic. This aligns with previous research, which has demonstrated that inadequate knowledge and insufficient public education may affect dietary supplement use decisions.37,38 Furthermore, safety concerns were also identified as a reason for decreased supplement use, being cited by 29.2% of these participants. This hesitation about supplement consumption is compatible with earlier studies that identified safety concerns, particularly potential drug–supplement interactions, as an important reason limiting supplement use.39,40 Financial constraints were another reason for dropping intake, with one-quarter of participants (25.0%) reporting high cost as a reason for reducing supplement use. Previous studies support our observation, reporting that socioeconomic factors contribute to reduced regular use of nutritional supplements.31,41,42
From a risk management perspective, the transition from occasional to daily supplement use (rising to 31.4%) may raise potential health risks that warrant public health attention. Increased micronutrient consumption may carry risks associated with excessive intake and potential nutrient-drug interactions, particularly among individuals taking medications or managing chronic conditions. In addition, the reported lack of knowledge regarding proper supplement use underscores the importance of evidence-based risk communication addressing safe dosages, upper intake levels, and the potential benefits and risks of supplementation.
Another interesting finding from this survey was the significant increase in the perceived importance of dietary supplement intake after the pandemic (p < 0.001). The proportion of participants rating supplements as “very important” rose sharply from 17.3% before to 59.5% after the pandemic. On the other side, a decrease in the lower importance categories was detected. Linking these findings together, we concluded that the perceived value of supplements was amplified after the pandemic. Similar results were reported in earlier studies conducted during the acute phase of the pandemic in Malaysia, Iraq and Saudi Arabia, suggesting people believed that infection severity could be managed by dietary supplements.31,43
Globally, most COVID-era cross-sectional studies have focused on the acute pandemic phases.40,44 Within Jordan and other Middle East regions, research tracking health behavioral changes after the pandemic and comparing results with pre-pandemic baselines remains scarce. As far as we know, this makes our study one of the first comprehensive investigations in Jordan that evaluates supplement use years after the initial COVID-19 outbreak. Our results indicate that the increase in dietary supplement use extended beyond the active phase of the pandemic and was still observed in the post-pandemic period. These findings support the need for public health authorities, including the Jordanian Ministry of Health, to strengthen educational plans and evidence-based public health strategies that provide guidance on the proper use of dietary supplements, indications of use, potential benefits, and adverse risks. Incorporating discussions of supplement use into healthcare consultations may also help support informed and safe use. Finally, longitudinal studies are warranted to explore whether these health behaviors will remain over time.
Study Limitations
This study has several limitations. First, we were unable to infer causal relationships between the COVID-19 pandemic and changes in supplement use because of the cross-sectional nature of this study. Second, the possibility of recall bias exists, as the data relied on participants’ self-reports, particularly given the time elapsed between the pre-pandemic reference period and survey completion. Also, the potential differences in recall between online and face-to-face participants cannot be ruled out. Third, the majority of participants were female and resided in Northern Jordan, which could be overrepresented. Fourth, these findings obtained from Jordan cannot be generalized to other countries with different cultural norms or supplement markets. Another limitation is related to the sample-size calculation, which was based on precision for estimating population proportions rather than statistical power specifically for the paired comparisons or multivariable ordinal logistic regression analyses. Additionally, potential confounding factors such as income, healthcare access, pregnancy status, health literacy, and exposure to health information were not assessed in this survey, which may have limited the ability to account for their potential influence on changes in dietary supplement use. In addition, the use of mixed-mode recruitment (online and face-to-face) may have introduced mode-related differences in responses. Although recruitment mode was included in the multivariable analysis, potential influences related to differences in survey administration or the characteristics of participants reached through each mode cannot be completely excluded.
Conclusion
This study revealed notable changes in dietary supplement consumption behaviors in Jordan after the COVID-19 pandemic. Nearly half of the participants reported increasing their dietary supplement use years after the pandemic, accompanied by a marked shift toward daily consumption and a greater perceived importance of dietary supplements for health maintenance. Baseline pre-pandemic supplement-use frequency, recruitment mode and COVID-19 infection severity were significantly associated with these behavioral changes, highlighting the importance of considering previous supplement-use patterns, recruitment mode and COVID-19 illness experience when interpreting changes in supplement use. Also, lack of knowledge about proper use and safety concerns were reported among participants who decreased their supplement consumption. Together, these findings highlight the importance of evidence-based educational programs that support the appropriate and safe use of dietary supplements in Jordan.
Acknowledgments
We are thankful to all participants for their participation in this study.
Funding Statement
The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.
Data Sharing Statement
Due to privacy and ethical restrictions, the data presented in this study are not publicly available. It will be available upon reasonable request from the corresponding author.
Ethics Approval and Consent to Participate
The study was conducted in accordance with the Declaration of Helsinki and was reviewed and approved by the Research Ethics Committee at Al al-Bayt University (Reference No.: IRB_AABU_8). Consent was obtained from all participants involved in the study. Consent was implied through the voluntary completion and submission of the questionnaire.
Consent to Publish
This was deemed not applicable.
Author Contributions
All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.
Disclosure
The authors report no conflicts of interest in this work.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Due to privacy and ethical restrictions, the data presented in this study are not publicly available. It will be available upon reasonable request from the corresponding author.