Next Article in Journal
Structural Topic Model Analysis of Mask-Wearing Issue Using International News Big Data
Previous Article in Journal
Role of Chest Imaging in Viral Lung Diseases

Dietary Intake and Supplement Use Among Saudi Residents during COVID-19 Lockdown

Department of Food Science & Nutrition, College of Food & Agriculture Science, King Saud University, Riyadh 11495, Saudi Arabia
Biomarkers of Chronic Diseases, Biochemistry Department, King Saud University, Riyadh 11451, Saudi Arabia
Department of Food Science and Human Nutrition, College of Applied and Health Sciences, A’ Sharqiyah University, Ibra 400, Oman
King Abdulaziz Medical City, Riyadh 14611, Saudi Arabia
Author to whom correspondence should be addressed.
Academic Editor: Paul B. Tchounwou
Int. J. Environ. Res. Public Health 2021, 18(12), 6435;
Received: 18 May 2021 / Revised: 12 June 2021 / Accepted: 13 June 2021 / Published: 14 June 2021
(This article belongs to the Section Health Behavior, Chronic Disease and Health Promotion)


Healthy diet and supplement use may prove as sustainable strategies to lower COVID-19 infection. Our study investigated the dietary changes before and during lockdown and observed dietary supplements (DS) use among residents in Saudi Arabia. This cross-sectional study collected data via an online electronic survey questionnaire among males (N = 921) and females (N = 1044) residing in Saudi Arabia, 15 years of age and above. There was a significant decrease in the prevalence of males (before vs. during lockdown) having improved changes in dietary habit (68.6% vs. 65.8%; p = 0.004), which was similar in female participants (69 vs. 73.4% vs. 69%; p < 0.001). The frequency of multivitamin users among COVID-19 participants was significantly lower than non-users (44.4 vs. 55.6; p < 0.003). Male respondents within 26–35 years of age were more likely to use multivitamin supplements than females (30.1 vs. 22.6%; p < 0.05) of same age group. Predictors for DS use were increased age group, income, education level and COVID-19 status. In conclusion, an increase in unhealthy diet behavior was observed among Saudi males and females during the pandemic lockdown and the predictors of DS use included increased age, income, education level and COVID-19 status.
Keywords: diet behavior; dietary supplements; COVID-19; income; education; multivitamin; Saudi Arabia diet behavior; dietary supplements; COVID-19; income; education; multivitamin; Saudi Arabia

1. Introduction

The coronavirus disease 2019 (COVID-19) was declared as global pandemic on 11 March 2020 by World Health Organization (WHO). The disease cost innumerable human lives and infected millions worldwide. At present, several COVID-19 vaccines have been approved for human use that have not been rolled out yet worldwide, due to challenges such as its surplus production, reasonable price, balanced distribution to all needy countries and delivery at the local level [1]. Moreover, to make the situation worse, high rates of vaccine hesitancy were reported from countries like in Jordan, Kuwait and Saudi Arabia [2], and in Europe, the rates of COVID-19 vaccine hesitancy were 41% in Italy and 26% in France [3,4]. These issues could pose a serious threat to the preventive measures aimed at controlling COVID-19 spread at the global level. Hence, in this situation, following preventive measures and strategies such as having a balanced diet may prove extremely beneficial, since the link between viral infection, nutrition and immune system, are well established [5].
Home confinement during COVID-19 impacted negatively on diet quality among adolescents from various countries such as Italy, Spain, Chile, Colombia and Brazil [6]. A recent report from Saudi Arabia demonstrated unhealthy changes in dietary habits, compromising the quality and quantity of the food [7]. The lockdown is a compulsory step to limit the rapid COVID-19 infection among individuals, however, this step has negative consequences especially related to diet and personal health. The confinement period is accompanied with reduced food accessibility and availability, which in turn compromises diet quality. Unhealthy dietary habits and lifestyle behavior including consumption of more food [8], snacking, decrease in sports activity, additional weight gain, psychological stress leading to change in dietary pattern have been reported recently [9,10,11]. Moreover, studies during COVID-19 lockdown reported a higher degree of emotional eating during the lockdown (e.g., sweets, pastries and alcohol), poor quality sleep, increase in the amount of screen time (for fun and entertainment), and sedentary behaviors [12,13,14].
For the last few decades, the use of dietary supplements has increased all over the world, with its consumption based on age, gender, illness prevention and nutritional deficiencies [15]. Based on European Food Safety Authority (EFSA), dietary supplements (DS) are defined as “concentrated sources of nutrients or other substances with a nutritional or physiological effect intended to supplement a normal diet” [16]. Recent studies from Saudi Arabia have shown the increased prevalence of DS use among its population. However, these studies recommend the consumers to use it with a doctor’s prescription and advocates for increased awareness about its health effects [17,18]. Studies have demonstrated the positive health effects of functional foods on respiratory, viral and parasitic, infectious, and inflammatory diseases [19]. As the COVID-19 pandemic is thought to be related to the immune system, the individuals are paying attention towards improving their diet in order to boost their immunity as a strategy to curb COVID-19 infection. Recently, the information in various social-media platforms and advertisements favoring the role of DS use to fight against COVID-19 prompted the consumer all around the world to increase its use [20,21].
Overall, the individual dietary habits and lifestyle behaviors are highly affected during this lockdown, leading them to acquire possible ways to combat against infection which may either prove beneficial or detrimental in terms of future health. Furthermore, since the lockdown coincided with the holy month of Ramadan, it is important to know how Ramadan observers in the era of COVID-19 changed their dietary behaviors in response to both the pandemic and the call for intermittent fasting, knowing that in theory, periodic fasting enhances the immune system [22]. It is therefore essential to study the extent of variation in dietary habits and observe the frequency of supplement use during the current pandemic to ascertain sustainable ways as a strategy to fight against rising infection. Hence, the aim of our present study is to observe dietary habit before and after lockdown period and demonstrate the DS use and its predictors among adult Saudi and non-Saudi population.

2. Materials and Methods

2.1. Study Design and Participants

This cross-sectional survey was conducted from 11 May to 6 June 2020, corresponding to almost 2 weeks during and after Ramadan (23 April–23 May 2020), using an online electronic survey. Within this timeframe, confirmed COVID-19 cases in Saudi Arabia increased from 41,014 to 98,869 [23]. Table 1 shows the timeline of events with respect to restrictions imposed in Saudi Arabia [24]. For the purpose of the study, the ‘lockdown’ refers to the curfews imposed. All adult Saudi citizens and residents (non-Saudis) 18-years-old and above with access to the internet were deemed eligible to voluntarily participate in the survey. All participants were asked for their email addresses for verification purposes only and to ensure that each participant completed the survey only once. The study design and protocol were approved by the Ethics Committee for Scientific Research and Post Graduate Studies at the College of Science, King Saud University, Saudi Arabia (reference# KSU-HE-20-246). The survey had no risks other than potential inconvenience during participation.

2.2. Questionnaire

The questionnaire included a cover letter in Arabic and English. It consisted of demographic and social information, and statements in Likert scale format to determine changes in dietary habits before and during lockdown. Participants have to indicate their habits before and during lockdown for the same question. Experts in the related field reviewed the questionnaire and several revisions were made to strengthen the reliability and enhance scientific value of the data to be collected. A pilot study (N = 75 participants) was performed to confirm reliability and validity of the questionnaire and obtained Cronbach’s α, which was noted to be excellent (84%). After completion, the questionnaire was transferred to an online link for distribution to different social media outlets throughout Saudi Arabia.
The questionnaire consisted of following sections:
Anthropometry and Sociodemographic characteristics, including age, sex, marital status, nationality, family income, family members, educational qualification, employment status, and region. The family income was categorized depending on the amount of Saudi Arabian Riyal (1 SAR = 0.266 USD)
The dietary habit and behavior questionnaire before and during the pandemic lockdown based on Likert scale statement among all, male and female participants.
Supplements used during the quarantine, including dietary supplements containing vitamin D, selenium, zinc, and vitamin C based on gender, COVID-19 status, education, income, age, and nationality.

2.3. Sample Size Calculation

Based on the prevalence of supplement use in Saudi population reported in the literature, i.e., 22% [25], the minimum required sample size at 95% CI with 2% precision was 1648. To overcome the expected non-response rate of 20%, a questionnaire was sent to 1965 potential participants.

2.4. Data Analysis

Analysis was done using SPSS version 16.5 (SPSS Inc., Chicago, IL, USA). Continuous variables were presented as mean ± standard deviation while categorical variables were presented as frequencies (N) and percentages (%). The chi-Square test was used to determine differences between categorical variables of interest. The independent t-test was used to determine differences between normal continuous variables. The McNemar test was used to examine differences in dietary habits before and during lockdown. To examine the predictors of DS use, binomial logistic regression analysis was performed (Odds Ratios and 95% CI) with supplementation as dependent and socio-demographics as independent variables. The p-value was considered significant at <0.05.

3. Results

3.1. Demographic Characterstics of the Participants

Table 2 represents demographic characteristic of the participants that have also been published in our previous paper [24]. The frequency of married male participants was significantly higher than females (61.6 vs. 45.4%, p < 0.001, respectively).

3.2. Dietary Pattern before and during Lockdown

The dietary habit pattern among participants as a whole (before vs. during lockdown) is presented in Table 3. A significantly low proportion of participants agree (combined proportion of strongly agree and agree) that they changed their diet for better health during lockdown than before (67.5 vs. 71.2%, p < 0.001). No significant differences were found with regards to statements that during the pandemic: they began to care more about healthy diet (71.4 vs. 71.6%, p > 0.05), they reduced their fast-food consumption (77.2 vs. 79%, p > 0.05), they have not eaten from any restaurant (73.8 vs. 75.3%, p > 0.05), and a higher proportion disagree for increased consumption of homemade food (47.8 vs. 44.9%, p > 0.05) than before. However, a significant proportion of participants avoided drinking coffee from coffee shop during lockdown as compared to before (41.2 vs. 40%, p = 0.040).
The dietary habit pattern among males (before vs. during lockdown) exhibited a significant low proportion of male participants agree (combined proportion of strongly agree and agree) that during lockdown: there are better changes in their dietary habit during lockdown (65.8 vs. 68.6%, p = 0.004). However, no significant differences were found with regards to the statements: that they reduced their fast-food consumption (78.8 vs. 80.3%, p > 0.05), they have not eaten from any restaurant (73.5 vs. 75.1%, p > 0.05), and they ate more fresh fruits and vegetables (64.7 vs. 66.8%, p > 0.05), but high proportion disagree, although insignificant, about increased consumption of homemade food (46.4 vs. 42.2%, p > 0.05), than before. Similarly, the dietary behavior among females (before and during lockdown) demonstrated a significant low proportion of female participants agree (combined proportion of strongly agree and agree) that during the pandemic: there are better changes in their dietary habit (69 vs. 73.4%, p = 0.002). However, no significant differences were found with regards to the statements that: they began to care more about healthy diet (69.5 vs. 71.1%, p > 0.05), they reduced their fast-food consumption (75.9 vs. 78%, p > 0.05), they have not eaten from any restaurant (74 vs. 75.5%, p > 0.05), but high proportion disagree about increased consumption of homemade food (49.2 vs. 47.3%, p > 0.05), than before. Furthermore, a high frequency of females avoided drinking coffee from coffee shop during lockdown as compared to before (41.9 vs. 39.8%, p < 0.035).

3.3. Dietary Supplement Use among Participants

The overall use of supplements among participants based on gender and among COVID-19 patients and their family members is shown in Table S1. The frequency of various supplement (multivitamin, vitamin D, selenium, and zinc) use were non-significantly high among males than females (26 vs. 21.5%; 21.5 vs. 19.7%; 0.7 vs. 0.3%; 1.4 vs. 1.3%), respectively. Similarly, the overall use of multivitamin and zinc were non-significantly high in COVID-19 males than females (47.4 vs. 42.3), respectively, whereas, use of vitamin D and C were high in females than males (26.9 vs. 10.5; 19.2 vs. 10.5), respectively. Table S2 represents the frequency of supplement use based on COVID status. Among participants diagnosed with COVID-19, the frequency of multivitamin users was significantly low as compared to non-users (44.4 vs. 55.6; p < 0.003). No other significant difference was observed for supplement use among non-COVID-19 participants and their family members. Table S3 exhibited gender difference for supplement use among participants based on their education, income an age. The male participants specifically between 26–35 years of age showed significant higher use of multivitamin than females (30.1 vs. 22.6%; p < 0.054) of the same age group. Table S4 represents the DS use based on nationality and gender. No significant difference was observed among males and females for DS use in Saudi and non-Saudi nationals.

3.4. Predictors of DS Use

Table 4 represents the results of logistic regression outcomes demonstrating the independent predictors of supplement use among participants according to socio-demographic and COVID-status. The significant strong predictors were increased age group, high income and education level and positive COVID-19 status. The multivitamin users were less likely to belong younger age group (15–25 years) (OR: 0.6, 95% CI: 0.5–0.8) as compared to higher age groups. The participants between 15–25 years of age were less likely to be Vitamin D users than high age groups, but the 95% CI included 1. The odds of vitamin C use were 2-fold (95% CI: 1.3–3.2) higher among participants with high income level than low income. Compared to participants with higher education (PhD), those with low educational (bachelor) had a significant lower probability of using vitamin D (OR: 0.6, 95% CI: 0.5–0.9). The probability of multivitamin use was 2.5-fold (95% CI: 1.4–4.5) higher among participants with positive COVID-19 status as then negative status.

4. Discussion

The COVID-19 pandemic had a huge impact on human diet and health among all sections of population worldwide. The present study observed an unhealthy change in dietary habit and behavior during the pandemic among all participants irrespective of gender and demonstrated non-significant increase in DS use among males than females. The strong determinants of DS use among participants were increased age, high income and education level and positive COVID-19 status.

4.1. Dietary Habit and Behavior

The dietary habits among participants demonstrated an increase in unhealthy diet behavior during lockdown, including less care about their health, increased fast-food consumption, low consumption of fresh fruits and vegetables, and lower preference to homemade food, as compared to before pandemic. The unhealthy change in diet pattern during the pandemic and lockdown period have been reported from around the world, including middle east countries. Study from United Arab Emirates revealed negative lifestyle changes, unbalanced food choices, and psychological problems among individuals during the COVID-19 pandemic [14]. An Italian survey (aged between 12 and 86 years) demonstrated slight weight gain among 48.6% of its population while 37.4% and 35.8% of the study population responded to eat more or less healthy food (fruit, vegetables, nuts and legumes), respectively. Although, the study pointed some healthy behavior change among participants (3.3%) who quit smoking during COVID-19 emergency, most of the population responded not to have changed its habits (46.1%), while 37.2% made them worse [26].
With some favorable changes, such as increase in the consumption of homemade food, the Saudi adults had been shown to compromise the quality and quantity of their diet during the pandemic [7]. The COVID-19 pandemic lockdown significantly affected eating habits in German young adults with one-third of study subjects eating more (31.2%), while (16.8%) ate less compared to the time before lockdown [8]. The “Effects of home Confinement on multiple Lifestyle Behaviours during the COVID-19 outbreak (ECLB-COVID19)” Online Survey demonstrated unhealthy eating behavior during lockdown period with increased consumption of unhealthy food, uncontrolled eating and snacking between meals [27]. Our result corroborates the above findings [8,19,20,26,27] showing majority of our participants worsen their dietary habits during lockdown including all, male and female (67.5, 65.8, and 69%), respectively.
The unhealthy dietary habits are more prevalent in Saudi adult population specifically in females than males [28,29]. Our present study agrees with these findings showing overall less interest towards their healthy diet (71.4%), while females exhibited significant less attention towards their healthy diet during the pandemic as compared to before (69.5 vs. 71.1%). A recent polish study demonstrated increased consumption of homemade meals among ProHealth individuals as compared to unhealthy dietary pattern shown by respondents with decrease in homemade meal consumption [30]. On the contrary to Saudi study [7], the present study showed participants with decreased consumption of home cooked meals during lockdown. The results support the above study [30] indicating low consumption of homemade food as one of the factors responsible for overall unhealthy diet behavior during the pandemic lockdown. Moreover, we assume participant’s lack of time and busy lifestyle as a barrier to spent considerable time on healthy meal preparation with easy options such as fast-food consumption and food from restaurant or quick home delivery from other sources. Although the consumption of fruits and vegetables in Saudi adolescent is reported to be far less than recommended [31], its consumption is higher in males as compared to females [32]. However, in contrast to above trend, the present study exhibited significant low consumption of fresh fruits and vegetables in males during the pandemic lockdown than before (64.7 vs. 66.8%). The reason seems to be limited grocery shopping from supermarkets or malls due to their closures, increased online shopping, increased fast-food consumption and paying less attention to healthy food choices. The shutdown and restriction of coffee shops, and restaurants during the pandemic favored an increase in food delivery services. Although considered safe to aid in social distancing, reports suggest that this food distribution approach has a great potential of spreading COVID-19 infection [33,34].
A study from Kuwait revealed no remarkable changes in beverage consumption except for decrease in Americano coffee and fresh juice, possibly due to the closure of coffee shops as a precautionary measure during the pandemic [13]. Our present study supports the above findings [13], demonstrating low coffee consumption specifically in females, possibly due to closure of shops as well as fear of getting contaminated beverage or infection from food delivery services [32,33] during COVID-19 lockdown as compared to before.

4.2. Dietary Supplement Use

The possible role of dietary supplement (such as vitamin C, vitamin D, omega 3 polyunsaturated fatty acids, probiotics, and zinc) as therapeutic agent to fight against COVID-19 infection are under clinical investigation and still not recommended for COVID-19 prevention and treatment [20]. Based on the Council for Responsible Nutrition (CRN)-funded COVID-19 survey (31 July 2020 to 4 August 2020) in US, 91% of DS consumers who increased their supplementation usage was during COVID-19 pandemic, with males consuming more DS than females (47 vs. 39%) with more users aged 18–34 (at 65%). DS consumers increased the usage of specific supplements such as multivitamins, vitamin C, and vitamin D, with usage growing 59%, 44%, and 37%, respectively [35]. The major reasons for increased DS usage were to improve immune strength, and health/wellness with specific augmented use of multivitamin (59%), vitamin C (44%), and vitamin D (37%) [36]. Based on gender, our present results are in agreement with the above survey showing overall increased DS use (multivitamin, vitamin D, selenium, and zinc) among males than females. In case of hospitalized COVID-19 patients, nutritional strategies are thought to improve the condition, as malnutrition is a risk factor to COVID-19 patients [37]. Therefore, DS use (vitamin C, vitamin D, and zinc) may be an effective method to maintain adequate dietary intake for optimal immune function.
Some of the nutrients, vitamins (A, C, D, E, B6, B12, and B9), and minerals (selenium, magnesium, zinc, and copper) are known to play important roles to strengthen our immune systems [38] and so might impact on the treatment of COVID-19.Internet information about methods of combating COVID-19 infection including the use of DSs, differ greatly depending on authenticity of the website (e.g., governmental or commercial) and sometimes compromises quality or may even provide potentially harmful information [39]. A recent study from Saudi Arabia reported that most of the information for the herbal products and DS use were obtained from social media and internet. Moreover, the consumers make their own choice to continue or stop its use based on their personal awareness, knowledge and health condition. In addition, vitamin C was the most commonly used food supplement to reduce the chance of contracting COVID-19 [40]. In our present study, males with positive COVID-19 status showed non-significantly high use of multivitamin and zinc than females, while female COVID-19 patient used more vitamin D and C than males. Moreover, among participants with COVID-19 status, the percentage of multivitamin users was significantly low than non-users. Based on above discussion, there is no plausible reason for these uncertainties in percentage of various DS use based on gender and COVID-19 status. However, our results indicate that participants are choosing and stopping the DS use at their own will without any scientific evidence or recommendation about the role of DS use to treat or prevent COVID-19. In addition, our results supported the abovementioned US survey [35] showing male participants of age (26–35 years) using more multivitamin than females of the same age.

4.3. Predictors of DS Use

The strong predictors of DS use among our participants were increased age group and high income. As discussed above, the majority of the multivitamin users in our present study belong to 26–25 years of age group. A recent study about the prospective association between habitual use of vitamin D supplements and risk of COVID-19 infection demonstrated that habitual users of vitamin D supplements were elder as compared to non-users [41]. Our present study corroborates the above findings showing young participants between 15–25 years of age as less likely to be vitamin D users than other higher age groups. The more common use of vitamin D supplements among older adults may prove beneficial in this population, as vitamin D deficiency, as well as diabetes in the Saudi population have proven to be significant risk factors for COVID-19 mortality [42,43,44,45].
Although not significant and uniform, the overall use of various DS was higher among those with high education level. For instance, the overall (positive response among males and females) multivitamin use was high among those having master’s level than bachelor and high school (56.6, 47,2, and 46.2), respectively. Similarly, the overall vitamin D and zinc use was highest (53.4, 5.2%, respectively), among participants with PhD level than other lower educational levels. A similar non-significant pattern was obtained among DS users based on income. The overall multivitamin and vitamin D use was high among those with >5000 SAR than <5000 SAR. High education level had been shown to have a direct association with use of DS [46] Moreover, DS and multivitamin use was shown to be significantly higher among those with a high household income [47].
Our present findings supported the above studies showing increased DS use within the high-income (>5000–7000 SAR and 8000–16,000 SRA) range as compared to low-income level (<5000 SAR). Similarly, the probability of DS use was higher among participants with higher-education levels (PhD) than bachelor degree. As it is clear from Table 4, COVID-19 status is a strong determinant showing increased multivitamin use among those who are COVID-19 positive than COVID-19 negative (44.4 vs. 24.5), respectively.

5. Strength and Limitations

To the best of our knowledge, this is the first study in Saudi Arabia that investigated dietary habits and the use of various supplements among both Saudi and non-Saudi population during COVID-19. The strength of our study includes the large sample size during this critical period and reaching the target population in different geographical locations. However, there are a few limitations that need to be considered while interpreting the results of the present study. Due to the cross-sectional nature of the study design itself, we are not able to identify exact causality between the study variables. Moreover, there are limited studies that have evaluated DS’s use based on gender and COVID-19 status, limiting our ability to compare our present findings with other studies. Our results demonstrate a limited number of DS use predictors, with the possibility of missing some important factors of DS use to be taken into account. It is possible that an online survey might not reach some of the target population, due to their location or internet unavailability.
Despite these limitations, the findings of the current study provide the evidence and direction for future research and recommends health organizations to focus on disseminating nutrition awareness about healthy diet behavior and quality food choices as sustainable dietary alternatives, specifically during current pandemic situations. As far as DS use is concerned, the consumers need effective education about authentic websites from which to obtain correct information, and to develop awareness and understanding of both the beneficial and detrimental effects of DS use in COVID-19 treatment and infection. Further investigations and clinical trials are required to establish the role of DS in prevention of COVID-19 infection, and to determine whether DS’s exhibit any real therapeutic value against this pandemic disease.

6. Conclusions

The findings of our study demonstrated a negative impact of COVID-19 lockdown on dietary habit and behavior, with the majority of male and female participants following unhealthier patterns than before. The participants responded that they cared less about a healthy diet, increased their fast-food consumption, and reduced consumption of homemade food and fresh fruit and vegetables during lockdown compared to before. The prevalence of DS use was higher among males than females. Male participants with COVID-19 status used more multivitamin and zinc, while females with positive COVID-19 status used more vitamin D and C. The significant strong predictors of DS use were increased by age group, high income and education level and positive COVID-19 status.

Supplementary Materials

The following are available online at, Table S1: Percentage of supplement use in Gender and COVID-19 Patients and family members. Table S2: Percentage of supplement use according to COVID-19 status. Table S3: Gender distribution among participants for Supplementation use according to Education, Income, and Age. Table S4: Dietary Supplement use based on nationality and gender.

Author Contributions

Conceptualization, H.A.A. and N.M.A.-D.; data collection, G.A.A. and H.A.A.; methodology and validation, H.A.A.; formal analysis, S.D.H.; data curation, supervision and project administration, H.A.A. and N.M.A.-D.; writing—original draft preparation, N.K.; writing—review and editing, H.A.A. and N.K. All authors have read and agreed to the published version of the manuscript.


This work was supported by the Deanship of Scientific Research, Chair for Biomarkers of Chronic Diseases (CBCD), KSU, Riyadh, Saudi Arabia.

Institutional Review Board Statement

The study was conducted according to the guidelines of the Declaration of Helsinki, and by the Ethics Committee for Scientific Research and Post Graduate Studies at the College of Science, King Saud University, Saudi Arabia (reference# KSU-HE-20-246).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The data used in this study is available on reasonable request from the corresponding author.

Conflicts of Interest

The authors declare that they have no competing interests. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.


  1. Wouters, O.J.; Shadlen, K.C.; Salcher-Konrad, M.; Pollard, A.J.; Larson, H.J.; Teerawattananon, Y.; Jit, M. Challenges in ensuring global access to COVID-19 vaccines: Production, affordability, allocation, and deployment. Lancet 2021, 397, 1023–1034. [Google Scholar] [CrossRef]
  2. Sallam, M.; Dababseh, D.; Eid, H.; Al-Mahzoum, K.; Al-Haidar, A.; Taim, D.; Yaseen, A.; Ababneh, N.A.; Bakri, F.G.; Mahafzah, A. High Rates of COVID-19 Vaccine Hesitancy and Its Association with Conspiracy Beliefs: A Study in Jordan and Kuwait among Other Arab Countries. Vaccines 2021, 9, 42. [Google Scholar] [CrossRef]
  3. Graffigna, G.; Palamenghi, L.; Boccia, S.; Barello, S. Relationship between Citizens’ Health Engagement and Intention to Take the COVID-19 Vaccine in Italy: A Mediation Analysis. Vaccines 2020, 8, 576. [Google Scholar] [CrossRef] [PubMed]
  4. Peretti-Watel, P.; Seror, V.; Cortaredona, S.; Launay, O.; Raude, J.; Verger, P.; Fressard, L.; Beck, F.; Legleye, S.; L’Haridon, O.; et al. A future vaccination campaign against COVID-19 at risk of vaccine hesitancy and politicisation. Lancet Infect. Dis. 2020, 20, 769–770. [Google Scholar] [CrossRef]
  5. Suardi, C.; Cazzaniga, E.; Graci, S.; Dongo, D.; Palestini, P. Link between Viral Infections, Immune System, Inflammation and Diet. Int. J. Environ. Res. Public Health 2021, 18, 2455. [Google Scholar] [CrossRef]
  6. Ruiz-Roso, M.B.; Padilha, P.D.C.; Mantilla-Escalante, D.C.; Ulloa, N.; Brun, P.; Acevedo-Correa, D.; Peres, W.A.F.; Martorell, M.; Aires, M.T.; Cardoso, L.D.O.; et al. Covid-19 Confinement and Changes of Adolescent’s Dietary Trends in Italy, Spain, Chile, Colombia and Brazil. Nutrients 2020, 12, 1807. [Google Scholar] [CrossRef]
  7. Alhusseini, N.; Alqahtani, A. COVID-19 pandemic’s impact on eating habits in Saudi Arabia. J. Public Health Res. 2020, 9. [Google Scholar] [CrossRef]
  8. Huber, B.C.; Steffen, J.; Schlichtiger, J.; Brunner, S. Altered nutrition behavior during COVID-19 pandemic lockdown in young adults. Eur. J. Nutr. 2020, 1–10. [Google Scholar] [CrossRef]
  9. Pellegrini, M.; Ponzo, V.; Rosato, R.; Scumaci, E.; Goitre, I.; Benso, A.; Belcastro, S.; Crespi, C.; De Michieli, F.; Ghigo, E.; et al. Changes in Weight and Nutritional Habits in Adults with Obesity during the “Lockdown” Period Caused by the COVID-19 Virus Emergency. Nutrients 2020, 12, 2016. [Google Scholar] [CrossRef] [PubMed]
  10. Alfawaz, H.A.; Wani, K.; Aljumah, A.A.; Aldisi, D.; Ansari, M.G.; Yakout, S.M.; Sabico, S.; Al-Daghri, N.M. Psychological well-being during COVID-19 lockdown: Insights from a Saudi State University’s Academic Community. J. King Saud Univ. Sci. 2021, 33, 101262. [Google Scholar] [CrossRef] [PubMed]
  11. Alfawaz, H.; Yakout, S.; Wani, K.; Aljumah, G.; Ansari, M.; Khattak, M.; Hussain, S.; Al-Daghri, N. Dietary Intake and Mental Health among Saudi Adults during COVID-19 Lockdown. Int. J. Environ. Res. Public Health 2021, 18, 1653. [Google Scholar] [CrossRef] [PubMed]
  12. Giacalone, D.; Frøst, M.B.; Rodríguez-Pérez, C. Reported Changes in Dietary Habits during the COVID-19 Lockdown in the Danish Population: The Danish COVIDiet Study. Front. Nutr. 2020, 7, 592112. [Google Scholar] [CrossRef] [PubMed]
  13. Husain, W.; Ashkanani, F. Does COVID-19 change dietary habits and lifestyle behaviours in Kuwait: A community-based cross-sectional study. Environ. Heal. Prev. Med. 2020, 25, 1–13. [Google Scholar] [CrossRef]
  14. Ismail, L.C.; Osaili, T.M.; Mohamad, M.N.; Al Marzouqi, A.; Jarrar, A.H.; Abu Jamous, D.O.; Magriplis, E.; Ali, H.I.; Al Sabbah, H.; Hasan, H.; et al. Eating Habits and Lifestyle during COVID-19 Lockdown in the United Arab Emirates: A Cross-Sectional Study. Nutrient 2020, 12, 3314. [Google Scholar] [CrossRef]
  15. Hys, K. Identification of the Reasons Why Individual Consumers Purchase Dietary Supplements. In Perspectives on Consumer Behaviour: Theoretical Aspects and Practical Applications; Sroka, W., Ed.; Springer Nature: Cham, Switzerland, 2020; pp. 193–209. [Google Scholar]
  16. European Food Safety Authority, Food Supplements. 2017. Available online: (accessed on 16 February 2021).
  17. AlGaeed, H.; Aljaber, M.; Alwehaibi, A.; Aljaber, L.; Arafah, A.; Aloyayri, M.; Binsebayel, O.; Alotaiq, S.; Alfozan, M.; Ahmed, I. General public knowledge and use of dietary supplements in Riyadh, Saudi Arabia. J. Fam. Med. Prim. Care 2019, 8, 3147. [Google Scholar] [CrossRef]
  18. Samreen, S.; Siddiqui, A.N.; Wajid, S.; Mothana, A.R.; Almarfadi, O.M. Prevalence and Use of Dietary Supplements among Pharmacy Students in Saudi Arabia. Risk Manag. Healthcare Polic 2020, 13, 1523–1531. [Google Scholar] [CrossRef]
  19. Del Castillo, M.D.; Iriondo-DeDond, A.; Martirosyan, D.M. Are functional foods essential for sustainable health? Ann. Nutr. Food Sci. 2018, 2, 1015. [Google Scholar]
  20. Adams, K.K.; Baker, W.L.; Sobieraj, D.M. Myth Busters: Dietary Supplements and COVID-19. Ann. Pharmacother. 2020, 54, 820–826. [Google Scholar] [CrossRef]
  21. Euromonitor International. Dietary Supplements in Poland. 2020. Available online: (accessed on 13 March 2021).
  22. Abunada, T.; Abunada, H.; Zayed, H. Fasting Ramadan during COVID-19 Pandemic: Immunomodulatory Effect. Front. Nutr. 2020, 7, 557025. [Google Scholar] [CrossRef]
  23. Johns Hopkins Coronavirus Resource Center. Available online: (accessed on 11 March 2021).
  24. Alfawaz, H.; Amer, O.E.; Aljumah, A.A.; Aldisi, D.A.; Enani, M.A.; Aljohani, N.J.; Alotaibi, N.H.; Alshingetti, N.; Alomar, S.Y.; Khattak, M.N.K.; et al. Effects of home quarantine during COVID-19 lockdown on physical activity and dietary habits of adults in Saudi Arabia. Sci. Rep. 2021, 11, 1–7. [Google Scholar] [CrossRef]
  25. Albakri, I.A.; Almalki, M.H.; Bukhari, S.M.; Ekram, S.S.; Aldhubayi, A.K.; Iqbal, M.M.; Al-Aloy, Y.A.F.; Almazrou, A.M.; Alotaibi, A.S.; Alruwaili, M.N.S.; et al. Prevalence of Intake of Dietary Supplements in the Population of Saudi Arabia, Jeddah. Egypt. J. Hosp. Med. 2017, 69, 1570–1575. [Google Scholar] [CrossRef]
  26. Di Renzo, L.; Gualtieri, P.; Pivari, F.; Soldati, L.; Attinà, A.; Cinelli, G.; Leggeri, C.; Caparello, G.; Barrea, L.; Scerbo, F.; et al. Eating habits and lifestyle changes during COVID-19 lockdown: An Italian survey. J. Transl. Med. 2020, 18, 229. [Google Scholar] [CrossRef]
  27. Ammar, A.; Brach, M.; Trabelsi, K.; Chtourou, H.; Boukhris, O.; Masmoudi, L.; Bouaziz, B.; Bentlage, E.; How, D.; Ahmed, M.; et al. Effects of COVID-19 Home Confinement on Eating Behaviour and Physical Activity: Results of the ECLB-COVID19 International Online Survey. Nutrients 2020, 12, 1583. [Google Scholar] [CrossRef] [PubMed]
  28. Al-Hazzaa, H.M.; AlZamil, H.A.; Alhakbany, M.A.; Alfadda, N.A.; Almusallam, S.M. A profile of physical activity, sedentary behaviors, sleep, and dietary habits of Saudi college female students. J. Fam. Community Med. 2019, 26, 1–8. [Google Scholar] [CrossRef]
  29. Alhazmi, A.; Aziz, F. Dietary assessment and its awareness in female students from different Health Departments: Unhealthy diet with normal BMI. J. Public Health Res. 2020, 9, 1799. [Google Scholar] [CrossRef]
  30. Górnicka, M.; Drywień, M.; Zielinska, M.; Hamułka, J. Dietary and Lifestyle Changes During COVID-19 and the Subsequent Lockdowns among Polish Adults: A Cross-Sectional Online Survey PLifeCOVID-19 Study. Nutrients 2020, 12, 2324. [Google Scholar] [CrossRef] [PubMed]
  31. Alsunni, A.A.; Badar, A. Fruit and vegetable consumption and its determinants among Saudi university students. J. Taibah Univ. Med. Sci. 2015, 10, 201–207. [Google Scholar] [CrossRef]
  32. Al-Hazzaa, H.M.; Abahussain, N.A.; Al-Sobayel, H.I.; Qahwaji, D.M.; Musaiger, A.O. Physical activity, sedentary behaviors and dietary habits among Saudi adolescents relative to age, gender and region. Int. J. Behav. Nutr. Phys. Act. 2011, 8, 140. [Google Scholar] [CrossRef] [PubMed]
  33. Nguyen, T.H.; Vu, D.C. The largest epicenter of the coronavirus outbreak in Vietnam. Infect. Control. Hosp. Epidemiol. 2020, 1–2. [Google Scholar] [CrossRef]
  34. Burdorf, A.; Porru, F.; Rugulies, R. The COVID-19 (Coronavirus) pandemic: Consequences for occupational health. Scand. J. Work Environ. Health 2020, 46, 229–230. [Google Scholar] [CrossRef]
  35. CRN-funded COVID-19 Survey. Available online: (accessed on 13 March 2021).
  36. Nutritional Outlook. Americans confident in dietary supplement effectiveness and quality in 2020, including during COVID-19 pandemic, CRN surveys show. Available online: (accessed on 13 March 2021).
  37. Brugliera, L.; Spina, A.; Castellazzi, P.; Cimino, P.; Arcuri, P.; Negro, A.; Houdayer, E.; Alemanno, F.; Giordani, A.; Mortini, P.; et al. Nutritional management of COVID-19 patients in a rehabilitation unit. Eur. J. Clin. Nutr. 2020, 74, 860–863. [Google Scholar] [CrossRef]
  38. Calder, P.C.; Carr, A.C.; Gombart, A.F.; Eggersdorfer, M. Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections. Nutrients 2020, 12, 1181. [Google Scholar] [CrossRef]
  39. Rachul, C.; Marcon, A.R.; Collins, B.; Caulfield, T. COVID-19 and ‘immune boosting’ on the internet: A content analysis of Google search results. BMJ Open 2020, 10, e040989. [Google Scholar] [CrossRef] [PubMed]
  40. Alyami, H.S.; Orabi, M.A.; Aldhabbah, F.M.; Alturki, H.N.; Aburas, W.I.; Alfayez, A.I.; Alharbi, A.S.; Almasuood, R.A.; Alsuhaibani, N.A. Knowledge about COVID-19 and beliefs about and use of herbal products during the COVID-19 pandemic: A cross-sectional study in Saudi Arabia. Saudi Pharm. J. 2020, 28, 1326–1332. [Google Scholar] [CrossRef] [PubMed]
  41. Ma, H.; Zhou, T.; Heianza, Y.; Qi, L. Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (COVID-19) infection: A prospective study in UK Biobank. Am. J. Clin. Nutr. 2021, 113, 1275–1281. [Google Scholar] [CrossRef]
  42. Alguwaihes, A.M.; Al-Sofiani, M.E.; Megdad, M.; Albader, S.S.; Alsari, M.H.; Alelayan, A.; Alzahrani, S.H.; Sabico, S.; Al-Daghri, N.M.; Jammah, A.A. Diabetes and Covid-19 among hospitalized patients in Saudi Arabia: A single-centre retrospective study. Cardiovasc. Diabetol. 2020, 19, 1–12. [Google Scholar] [CrossRef] [PubMed]
  43. Alguwaihes, A.M.; Sabico, S.; Hasanato, R.; Al-Sofiani, M.E.; Megdad, M.; Albader, S.S.; Alsari, M.H.; Alelayan, A.; Alyusuf, E.Y.; Alzahrani, S.H.; et al. Severe vitamin D deficiency is not related to SARS-CoV-2 infection but may increase mortality risk in hospitalized adults: A retrospective case–control study in an Arab Gulf country. Aging Clin. Exp. Res. 2021, 33, 1415–1422. [Google Scholar] [CrossRef] [PubMed]
  44. Al-Daghri, N.M.; Amer, O.E.; Alotaibi, N.H.; Aldisi, D.A.; Enani, M.A.; Sheshah, E.; Aljohani, N.J.; Alshingetti, N.; Alomar, S.Y.; Alfawaz, H.; et al. Vitamin D status of Arab Gulf residents screened for SARS-CoV-2 and its association with COVID-19 infection: A multi-centre case–control study. J. Transl. Med. 2021, 19, 1–8. [Google Scholar] [CrossRef]
  45. Sheshah, E.; Sabico, S.; Albakr, R.M.; Sultan, A.A.; Alghamdi, K.S.; Al Madani, K.; Alotair, H.A.; Al-Daghri, N.M. Prevalence of diabetes, management and outcomes among Covid-19 adult patients admitted in a specialized tertiary hospital in Riyadh, Saudi Arabia. Diabetes Res. Clin. Pr. 2021, 172, 108538. [Google Scholar] [CrossRef]
  46. Alfawaz, H.; Khan, N.; Alfaifi, A.; Shahrani, F.M.; Al Tameem, H.M.; Al Otaibi, S.F.; Abudigin, W.I.; Al-Shayaa, M.S.; Al-Ghanim, S.A.; Al-Daghri, N.M. Prevalence of dietary supplement use and associated factors among female college students in Saudi Arabia. BMC Women’s Health 2017, 17, 1–7. [Google Scholar] [CrossRef]
  47. Alfawaz, A.H.; Khan, N.; AlOteabi, N.; Hussain, S.D.; Al-Daghri, N.M. Factors associated with dietary supplement use in Saudi pregnant women. Reprod. Heal. 2017, 14, 104. [Google Scholar] [CrossRef] [PubMed]
Table 1. Timeline of Events [24].
Table 1. Timeline of Events [24].
EventDatesCurfew HoursExceptions
Suspension of non-essential work15 March None
Nationwide curfew23 March–5 April6 a.m.–7 p.m.Makkah & Madinah (3 April)
Enhanced curfew6–25 April6 a.m.–3 p.m.None
Ramadan *26 April–22 May9 a.m.–5 p.m.Makkah
Eid Al Fitr *23–27 May24 h curfewNone
Phase 1 Partial Easing *28–30 May6 a.m.–3 p.m.Makkah
Phase 2 Partial Easing *31 May–20 June6 a.m.–8 p.m.Makkah
Note: * denotes events that unfolded during the study period (11 May–6 June 2020).
Table 2. Anthropometric and socio-demographic information of the participants.
Table 2. Anthropometric and socio-demographic information of the participants.
N1965921 (46.9)1044 (53.1)
Marital Status
860 (43.8)
1040 (52.9)
49 (2.5)
12 (0.6)
355 (38.5)
566 (61.6)
0 (0.0)
0 (0.0)
509 (48.8)
474 (45.4)
49 (4.7)
12 (1.1)
Non Saudi
1632 (83.1)
333 (16.9)
777 (84.4)
144 (15.6)
855 (81.9)
189 (18.1)
High School
165 (8.4)
1158 (58.9)
368 (18.7)
274 (13.9)
75 (8.1)
556 (60.4)
158 (17.2)
132 (14.3)
90 (8.6)
602 (57.7)
210 (20.1)
142 (13.6)
Family Monthly Income (Valid)
687 (35.0)
200 (10.2)
580 (29.5)
498 (25.3)
338 (36.7)
93 (10.1)
258 (28.0)
232 (25.2)
349 (33.4)
107 (10.2)
322 (30.8)
266 (25.5)
Employment Status
Own Business
1100 (56.0)
217 (11.0)
597 (30.4)
2 (0.1)
49 (2.5)
495 (53.7)
113 (12.3)
286 (31.1)
1 (0.1)
26 (2.8)
605 (58.0)
104 (10.0)
311 (29.8)
1 (0.1)
23 (2.2)
Family Members
545 (27.7)
700 (35.6)
587 (29.9)
133 (6.8)
261 (28.3)
319 (34.6)
276 (30.0)
65 (7.1)
284 (27.2)
381 (36.5)
311 (29.8)
68 (6.5)
Age (Year)(Min-Max)35.2 ± 13.1 (15–75)35.2 ± 13.1 (16–72)35.1 ± 12.9 (15–70)0.799
15–25 year
26–35 year
36–45 year
>45 year
609 (31.0)
516 (26.3)
411 (20.9)
429 (21.8)
292 (31.7)
231 (25.1)
187 (20.3)
211 (22.9)
317 (30.4)
285 (27.3)
224 (21.5)
218 (20.9)
Al Jawf
Al Qassim
Eastrn Province
Northern border
1629 (82.9)
7 (0.4)
8 (0.4)
5 (0.3)
81 (4.1)
4 (0.2)
7 (0.4)
72 (3.7)
27 (1.4)
2 (0.1)
11 (0.6)
762 (82.7)
6 (0.7)
0 (0.0)
0 (0.0)
37 (4.0)
0 (0.0)
2 (0.2)
31 (3.4)
14 (1.5)
1 (0.1)
6 (0.7)
867 (83.0)
1 (0.1)
8 (0.8)
5 (0.5)
44 (4.2)
4 (0.4)
5 (0.5)
41 (3.9)
13 (1.2)
1 (0.1)
5 (0.5)
Note: data presented as N (%). The p-values are obtained from the Pearson chi-square test.
Table 3. Dietary habit and behavior response before and during lockdown among participants (overall and gender based).
Table 3. Dietary habit and behavior response before and during lockdown among participants (overall and gender based).
Overall Participants MalesFemales
ParametersResponseBefore N (%)During (%)p-ValueBefore N (%)During (%)p-Value Before N (%)During (%)p-Value
After COVID 19, my dietary
habits changed for the better
Disagree233 (11.8)296 (15.1)<0.001115 (12.5)139 (15.1)0.004118 (11.3)157 (15.0)0.002
Agree1399 (71.2)1326 (67.5)632 (68.6)606 (65.8)767 (73.4)720 (69.0)
I began to care more about
healthy diet
Disagree246 (12.5)230 (11.7)0.752104 (11.3)91 (9.8)0.360142 (13.6)139 (13.4)0.771
Agree1407 (71.6)1403 (71.4)665 (72.2)677 (73.6)742 (71.1)726 (69.5)
Reduced my fast-food
Disagree149 (7.6)182 (9.3)0.20065 (7.1)84 (9.2)0.36284 (8.0)98 (9.4)0.473
Agree1553 (79.0)1518 (77.2)739 (80.3)726 (78.8)814 (78.0)792 (75.9)
Have not eaten from any
restaurant during the pandemic
Disagree184 (9.3)197 (10.0)0.49788 (9.5)91 (9.9)1.00096 (9.2)106 (10.2)0.473
Agree1480 (75.3)1450 (73.8)692 (75.1)677 (73.5)788 (75.5)773 (74.0)
Avoided drinking coffee
from coffee shop
Disagree784 (39.9)723 (36.8)0.040353 (38.3)339 (36.8)0.510431 (41.2)384 (36.7)0.035
Agree786 (40.0)810 (41.2)370 (40.2)373 (40.5)416 (39.8)437 (41.9)
Increased consumption
of food homemade
Disagree882 (44.9)941 (47.8)0.801389 (42.2)427 (46.4)0.377493 (47.3)514 (49.2)0.720
Agree660 (33.6)621 (31.6)319 (34.7)297 (32.2)341 (32.6)324 (31.0)
Ate more fresh fruits
and vegetables
Disagree278 (14.2)296 (15.0)0.640115 (12.5)135 (14.7)0.281163 (15.6)161 (15.4)0.795
Agree1297 (66.0)1278 (65.0)615 (66.8)596 (64.7)682 (65.3)682 (65.3)
Note: data presented as N (%). Strongly agree, agree and strongly disagree, disagree were combined as agree and disagree respectively. The McNemar test was used to obtain p-values.
Table 4. Odds ratios for dietary supplement use according to socio-demographics and COVID-19 status.
Table 4. Odds ratios for dietary supplement use according to socio-demographics and COVID-19 status.
MultivitaminVitamin DVitamin CZinc
OR (95%CI)pOR (95%CI)pOR (95%CI)pOR (95%CI)p
Age (Years)
15–25 Years0.6 (0.5–0.8)0.0010.7 (0.5–1.0)0.0360.8 (0.5–1.2)0.2611.4 (0.5–4.2)0.528
26–35 Years0.9 (0.7–1.2)0.4750.9 (0.7–1.3)0.6231.2 (0.8–1.7)0.3860.7 (0.2–2.5)0.541
36–45 Years1.0 (0.7–1.3)0.8210.9 (0.7–1.3)0.6171.1 (0.7–1.6)0.8111.7 (0.5–5.2)0.365
>45 YearsReference
Female0.9 (0.7–1.1)0.3290.9 (0.7–1.1)0.3341.0 (0.8–1.3)0.9670.9 (0.4–2.0)0.893
Income (SAR)
<5000 SAR0.9 (0.7–1.2)0.4730.9 (0.7–1.2)0.3571.1 (0.8–1.6)0.6281.0 (0.4–2.5)0.994
5000–7000 SAR1.2 (0.8–1.7)0.4101.2 (0.8–1.7)0.4002.0 (1.3–3.2)0.0030.3 (0.0–2.5)0.268
8000–16,000 SAR1.1 (0.9–1.5)0.3371.0 (0.7–1.3)0.9291.5 (1.0–2.2)0.0280.7 (0.3–2.1)0.578
>16,000 SARReference
Saudi1.2 (0.9–1.6)0.2641.0 (0.8–1.4)0.9450.9 (0.6–1.3)0.5480.9 (0.3–2.4)0.827
High School1.0 (0.7–1.6)0.9260.7 (0.4–1.1)0.0861.7 (1.0–3.0)0.0560.5 (0.1–2.3)0.347
Bachelor1.0 (0.7–1.3)0.8530.6 (0.5–0.9)0.0061.2 (0.8–1.8)0.4190.5 (0.2–1.3)0.171
Master1.2 (0.9–1.8)0.2490.7 (0.5–1.1)0.1081.2 (0.7–2.0)0.4550.2 (0.0–1.0)0.052
COVID-19 Status
Positive2.5 (1.4–4.5)0.0031.0 (0.5–2.0)0.9251.3 (0.6–2.9)0.5353.5 (0.8–15.4)0.093
Note: Data indicates odds ratios and 95% CI obtained using logistic regression with supplementation as dependent and socio-demographics as independent variables; p < 0.05 considered significant. Number of samples using Selenium were not enough to calculated ORs.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Back to TopTop