key: cord-0990226-l3z8d58g
authors: Francis, Tormalli V.; Sooriyaarachchi, Piumika; Jayawardena, Ranil
title: Usage of nutritional supplements to improve immunity during the COVID-19 pandemic: an online survey
date: 2022-04-18
journal: Clin Nutr Open Sci
DOI: 10.1016/j.nutos.2022.04.003
sha: c07780e6b5f1aa57ea8d30fa7f2f0bbd1b7d2d81
doc_id: 990226
cord_uid: l3z8d58g

Background and aims Proper nutrition to optimise immune function is mandatory as at present there is no specific medicine to cure COVID-19. Our study aimed to investigate the use of nutritional supplements and their key immunity enhancing components among Sri Lankans. Methods This current study was an online survey conducted during the period from 27th May to 2nd June 2021 disseminated via various social media platforms. Details were collected on highlighting the frequency and composition of nutritional supplements consumed. Results In a total of 3707 responders, a proportion of 25.5% (944) of the participants took supplements regularly, and 32.6% (1210), 14.5% (538), 27.4% (1015) intake were occasionally, rarely and never respectively. Older participants (>40 years of age) had a significantly higher intake of supplements than the younger counterpart of 31-35 years age group (OR:0.604; 95% CI, 0.451-0.809; p < 0.001). Almost half (46.0%) took vitamin C supplements and females tend to take more (OR: 1.325; 95% CI, 1.120-1.567; p < 0.001) of vitamin C when compared to males. Comparatively to the other groups regarding monthly income, the participants with the highest income category are more likely to take vitamin D (OR:1.899; 95% CI, 1.034-3.490; p = 0.039) and multivitamin (OR:3.222; 95% CI, 1.737-5.977; p < 0.001). The most commonly used main ingredients in home-made remedy was coriander in Sri Lanka. Conclusion The use of nutritional supplements and natural products to improve immunity during the pandemic were frequent among Sri Lankan adults. In general, older, female gender and high income was significantly associated with increased intake of the nutrient supplements.

The coronavirus disease 2019 (COVID- 19) pandemic has advanced relentlessly worldwide since the first cluster of cases of infection [1] . As of 31 st of May 2021, it has spread over 222 countries, and has caused a total of 17 million and 3.5 million active cases and deaths respectively [2] . The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a substantial increase in hospitalisations for pneumonia with multi-organ disease worldwide [3] . Expression of the virus ranges from asymptomatic to life-threatening, presenting flu-like symptoms to severe lung injury in high-risk older individuals with multiple co-morbidities [4] . COVID-19 remains a global health challenge, having triggered an enormous number of human causalities and serious economic losses to countries [5] . Therefore, infection prevention, early viral detection and identification of treatment protocols provide the best approach in controlling the disease spread.

Multiple therapeutic strategies are used to treat patients with COVID-19, while no specific drugs are recommended to cure it [6] . The fundamental prevention measures such as maskwearing, social distancing and handwashing are universally recommended [7] . In addition to the basic preventative measures, vaccination has been identified as a key strategy for preventing the infection globally [8] . A substantial population need to be vaccinated to achieve safe herd immunity to control transmission of the COVID-19 virus [9] . The demand for vaccines is expected to overcome the supply and disparities in vaccine doses across high and low-income countries can be seen [10] . In addition, it is well known that proper nutrition can support optimal immune function thus reducing the impact of infections [11] .

The global burden of the COVID-19 pandemic infection is significant, requiring further safeguards. Achieving a balanced diet has become extremely challenging during this epidemic J o u r n a l P r e -p r o o f [12] . Protein-energy malnutrition and/or micronutrient deficiency associates with impaired immune system [13, 14] . Micronutrient deficiencies are highly prevalent in the South Asian region and deficiencies of iron, zinc, vitamin D and vitamin B12 are well established [15] . A review evaluating nutrition-based interventions for respiratory viral infections, reported vitamins A and D as well as trace minerals like selenium and zinc to have immune-modulatory effects [16] . Furthermore, the same review showed vitamin C had no beneficial evidence against viral infections, and similarly vitamin E supplementation indicated no effect and may be detrimental [16] . During this epidemic, commonly recommended supplements by dieticians were fish oil, vitamin D, multivitamin, probiotics and vitamin C [17] .

Along with micronutrients, natural products with therapeutic properties such as ginger, turmeric, garlic and others hold immune-modulating properties that may improve immunity against diseases are utilised as home-based remedies [18] . According to a study conducted on the use of herbs and natural products in the Saudi population during the COVID-19 pandemic, 69.3% believed that these practices can improve their immunity [19] . Additionally, a survey in Bangladesh reported that 57.6% of the participants had used herbal foods/products, with tea (71%) being the most popular, followed by ginger (56.5%), black seed (32.8%), honey (30%), and clove (30%) [20] .

Hence, dietary supplements defined as usable amounts of micronutrients have become a growing interest during the COVID-19 as they are widely used to potentially improve immune health [21] . Moreover, complementary and alternate medicine as Ayurveda and herbal supplements are frequently used as treatments globally [22] . Sri Lanka, as a lower-middleincome country, is currently experiencing its most severe outbreak of the COVID-19 pandemic.

Therefore, the main aim of this online survey was to investigate the use of nutritional supplements and their key immunity enhancing components among Sri Lankans during the COVID-19 pandemic.

J o u r n a l P r e -p r o o f

The present study is a national level online survey conducted using Google forms, a web survey platform during the period from 27 th May to 2 nd June 2021. Recruitment of participants was carried out using multiple strategies. The link of the online survey was circulated across various social media platforms, the detailed methodology is published elsewhere [23] . No incentives were given to the participants and the active promotion of the questionnaire was completely voluntary. Informed consent was taken prior to the administration of the questionnaire. The web-based survey was performed accordingly to the ethical principles laid by the World Medical Association Declaration of Helsinki [24] . The nature of anonymity and the impossibility to trace any sensitive data required no ethical approval [25] .

The online questionnaire was constructed using Google Forms and was made available in all three official languages; English, Sinhala and Tamil. The participants could select the preferred language, and the questionnaire was anticipated to take 5-10 minutes to complete. The questionnaire was divided into two sections, each including personal and lifestyle details, with a focus on the use of nutritional supplements to improve immunity. The second part of the questionnaire collected details on the usage of "immune nutrients". The frequency and composition of nutritional supplements consumed were recorded. The frequency of the supplement intake was inquired using four options: regularly, occasionally, rarely or never. The respondents were asked to select the nutritional supplements they have consumed during this period from a list of nine options: vitamin C, vitamin D, multivitamin, kothamalli (Coriandrum sativum infused in water), Ayurvedic products, herbal products, home-made remedies, syrups and others. To obtain more details on home-based remedies, the most common ingredient used was asked via an open ended question.

Data were extracted from Google forms as an MS Excel spreadsheet (Version 16.50, Microsoft Corporation). The data were revised, coded and fed into the statistical software IBM SPSS version 23 (SPSS, Inc. Chicago, IL) for statistical analysis. Descriptive analysis based on the frequency and percentage distribution was performed for all demographic variables and the results were expressed as a percentage (%) and numbers (n). The chi-square test was used to determine differences between categorical variables of interest. Multinomial and binary logistic regression analyses were conducted to investigate the association between categorical variables (dependent) and continuous or categorical ones (independent). During regression analyses, certain demographic variables representing less than 1% of the sample were removed.

In addition, monthly family income groups of < 10,000 LKR and 10,000 -24,999 LKR were combined together as < 25,000 LKR category. Education level groups of no schooling, primary and secondary education also were combined to a new one category as 'secondary education or below'. The results of logistic regression analyses were reported as odds ratio (OR) and 95% confidence intervals (95%; CI). The p-value was considered significant at <0.05.

After removing potential duplicates and incomplete responses, a total of 3707 respondents were recorded before removing <1% categorical groups for analysis. Socio-demographic characteristics of the participants is presented in Table 1 . The majority belonged to the 26-30 years age group (24.7%; 913), were of females (59.6%; 2209) and had an education level of degree or above (69.1%; 2563). Survey conducted covered all 25 districts in the country with the highest reporting from Colombo (37.8%;1408) and most of the responders were from rural areas 40.1% (1488). Representation of all ethnic groups were recorded and the majority were Sinhalese (81.9%, 3036). In terms of employment status and monthly income, more than half of the participants were employed (63.0%; 2337) and over a quarter of participants had a monthly income of 50,000-99,000 LKR (26.6%; 986). Table 2 presents the associations between demographic variables and the frequency of taking nutritional supplements. Participants who never take supplements were of 27.4% (1015) whereas rarely, occasionally and regularly reported 14.5% (538), 32.6% (1210) and 25.5%

(944) respectively. Among all the demographic variables, age, gender, ethnicity, employment status and monthly family income of the respondents indicated strong significant associations with the four frequencies of supplementation intake from taking it regularly, occasionally, rarely or never (p < 0.05). The regression analysis among regular supplement intake by demographic variables was reported in the Supplementary Table 1 . The odds of regular intake of supplements are lower in all ages compared to the oldest group. Moreover, participants from 31-35 years age group reported significantly lower intake of supplements compared to older > 40 years age category (OR:0.604; 95% CI, 0.451-0.809; p = 0.001). In addition, males were less likely to have regular supplement intake (OR:0.589; 95% CI, 0.485-0.716; p < 0.001) compared to the female counterpart. However, a clear significant difference of regular J o u r n a l P r e -p r o o f supplement intake was seen among participants who earned more than > 200,000 LKR when compared with < 25,000 LKR (OR: 0.506; 95% CI, 0.336-0.761; p < 0.001). Table 3a and 3b present the vitamins and multivitamin users during the COVID-19 pandemic respectively. The usage of vitamin C, vitamin D and multivitamin among the participants were 46 .0% (1288), 8.6% (241) and 10.8% (302) respectively. As seen in Table 3a , vitamin D and multivitamin intake had a significant association with age (p < 0.05). Overall females were more likely to take vitamin C supplementation (OR: 1.325; 95% CI, 1.120-1.567; p < 0.001) when compared to males. A strong significant correlation resulted between all districts and areas of residence with supplementation (p < 0.001). Odds ratio presented in Table 3b exhibited the district of Kandy had a less likelihood for intake of vitamin C ( [26] . In Italy, most believed that strengthening immune defences through nutrition elements enhance the function of the immune system to reduce the risk of COVID-19 infection [27] .

In this study, various demographic factors were associated with the frequency of nutritional supplement intake. Regular supplement intake was seen greater among the older (> 40 years) participants in contrast to the younger counterpart. A similar pattern was observed in Bangladesh, where elderly individuals were more likely to take preventive supplements (OR: 2.93; 95% CI, 1.37-6.30; p = 0.004) [20] . Older age and/or existing co-morbidities are an increased risk factor for severe COVID-19 infection compared to the younger age group which may also cause elders to take extra measures to be more careful [28] . Higher intake of J o u r n a l P r e -p r o o f supplementation was also mostly seen across females than males. Our gender analysis results reflect similar patterns as of the online study among Polish adults [25] . A study which was conducted among the Google users across multiple countries to investigate their interests in nutritional supplements during the COVID-19 pandemic period revealed that, the difference of interest was either because of traditional medicine knowledge or regional beliefs in the specific country [29] . Consistently, the difference between the ethnic groups indicates they do not share the same knowledge and attitudes on supplements use [30] . The lower earning category of participants were significantly less likely to use supplements considering the supplements tend to be more expensive [31] . These results are similar to investigations done in other countries that have indicated supplement intake is greater among the high income populations [32, 33] .

Since a greater proportion of our participants were educated, there was no difference in supplement intake found. Whereas other related studies during COVID-19 discovered such preventive behaviours were higher among educated participants [20, 25] .

In this study, a larger proportion (46.0%;1288) used vitamin C supplements, which has been studied to stimulate various defense mechanisms including antimicrobial and immunomodulatory properties [34] . Nonetheless, a review on therapeutic vitamin C supplementation had no consistent effect on the severity and duration for common cold [35] .

A study in the USA with COVID-19 patients, administered high doses of ascorbic acid and had no significant decrease of symptoms in comparison to standard care (p = 0.25) [36] . Contrarily, vitamin D and multivitamin supplementation intakes were higher among participants who were older, employed and from affluent categories. Vitamin D and multivitamin supplementation are recommended as these can be effective especially among individuals who are either deficient and in self-isolation or have bad dietary practices [16] . Furthermore, another study exploring dietary supplements effect on COVID-19 recorded lower risk of infection in J o u r n a l P r e -p r o o f participants taking multivitamins by 13% (OR = 0.87; p < 0.001.) and vitamin D by 9% (OR = 0.91; p < 0.001) [37] . As vitamin D deficiency has been associated with COVID-19 mortality rate in the Asian region, vitamin D supplementation could have a vital role in the prevention or treatment of the disease [38, 39] . Accordingly, vitamin D supplementation was administered among elderly patients in France with COVID-19 and were less likely to exhibit severity (OR = 0.46; 95% CI, 0.01-0.81; p = 0.033) [40] . In comparison to these micronutrient supplements, other immunity enhancing products reported association with various factors; residing location and ethnicity which may have influenced by cultural practices and beliefs [41] . Besides, the use of such herbs and products was high probably due to the immediate availability in most households in Sri Lanka. Positive previous experiences with herbal therapy, as well as family traditions and practices, were among the most regularly mentioned reasons for the preferred use of herbal medicine in a focus group study in Germany [42] .

Herbs and spices have been extensively studied around the world due to their greater demand for its natural food antioxidant and antimicrobial activity [43] . The majority (59.5%) of participants in our study took kothamalli to enhance their immunity. Coriander, has a long history as a traditional medicine, although a review investigating its bioactive constituents reported no effectiveness when treated for respiratory ailments such as asthma or bronchiolitis [44] . In Bangladesh, 57.6% proportion recorded the use of herbal foods to lower the risk of COVID-19 [20] . Additionally, a Saudi population study revealed approximately 44.8% of the participants used herbs and natural products daily as a protective measure with a significant increase of intake after COVID-19 [19] . Similarly, use of herbal products among patients were prevalent in the case of the previous infectious MERS outbreak in South Korea reporting 76.1% of patients used one or more type of herbal products [45] . Home-made remedies were made including various herbs and natural products, the commonly used ingredients were coriander, J o u r n a l P r e -p r o o f ginger, lime, garlic and lemon. In Morocco as well, garlic and ginger were among the frequently consumed natural products during the pandemic [46] . Previous studies have reported that such ingredients could help in boosting an individual's immunity and may strengthen the immune system in general but just not related to the COVID-19 infection [47] [48] [49] .

The current study has some limitations. Self-reported weight and height values in this study population were inaccurate therefore BMI values were not utilised, a previous study conducted in Sri Lankan adults showed only one-fourth can report weight and height accurately [50] .

Among the questions asked regarding immunity enhancing supplements, only included the type and frequency of supplements but the doses are key. For instance, vitamin D supplementation as a dose of 5000IU per day is found to be more effective [16] . Moreover, not all multivitamins contain all the required vitamins and minerals as some may contain limited ingredients. A few of our questions were vague and overlapping. In the case of distinction between herbs and Ayurvedic products, as kothamalli/coriander is usually suggested under Ayurveda. In spite of the limitations, the main aim of this study was to report the types of supplements and the frequency of intake among the general public. Most countries studied similar patterns of usage frequency across various nutritional supplements [19, 20, 25, 26] . These data are critical for making informed policy decisions at the national level. There are false claims and some products may have adverse effects on human health. Further, some supplements may be overly expensive. The primary objectives of COVID-19 preventive measures are to follow public health guidelines, a balanced diet and daily physical movement. If deficiencies are present, nutritional supplementation may deem to be beneficial.

This study explored the proportion of Sri Lankans using nutrition supplements such as micronutrients, herbs and other natural products to enhance their immunity during the COVID-19 pandemic. Nearly three quarter of the population take micronutrient supplements to enhance immunity. Age, gender, residing district and income groups are strongly associated with supplement intake. Significant proportion of the participants take non-evidence based vitamins such as vitamin C and herbs such as coriander in Sri Lanka.

J o u r n a l P r e -p r o o f 

Novel coronavirus pandemic: A clinical overview

COVID Live Update: 171,084,997 Cases and 3,557,998 Deaths from the Coronavirus -Worldometer 2021

Pathophysiology, Transmission, Diagnosis, and Treatment of Coronavirus Disease 2019 (COVID-19): A Review

COVID-19 diagnosis and management: a comprehensive review

Current status of epidemiology, diagnosis, therapeutics, and vaccines for novel coronavirus disease 2019 (COVID-19)

Treatment options for COVID-19: The reality and challenges

Potential utilities of mask-wearing and instant hand hygiene for fighting SARS-CoV-2

COVID-19 vaccines: The status and perspectives in delivery points of view

Covid-19 vaccine frontrunners and their nanotechnology design

Unequal Vaccine Distribution Self-Defeating, World Health Organization Chief Tells Economic and Social Council's Special Ministerial Meeting -World | ReliefWeb

The role of micronutrients in support of the immune response against viral infections

Balanced diet is a major casualty in COVID-19

Strengthening the immune system and reducing inflammation and oxidative stress through diet and nutrition: Considerations during the covid-19 crisis

Protein-energy malnutrition and immunological responses

Nutrition and diabetes in South Asia

Enhancing immunity in viral infections, with special emphasis on COVID-19: A review. Diabetes and Metabolic Syndrome

Evaluation of dietary supplement, functional food and herbal medicine use by dietitians during the COVID-19 pandemic

Immunity: Plants as Effective Mediators

Prevalence of using herbs and natural products as a protective measure during the COVID-19 pandemic among the Saudi population: an online cross-sectional survey

Behavioral preventive measures and the use of medicines and herbal products among the public in response to Covid-19 in Bangladesh: A cross-sectional study

Dietary supplements and disease prevention-a global overview

Use of complementary and alternative medicines (CAMs) among type 2 diabetes patients in Sri Lanka: A cross sectional survey

Increased physical inactivity and weight gain during the COVID-19 pandemic in Sri Lanka: an online cross-sectional survey

World Medical Association declaration of Helsinki: Ethical principles for medical research involving human subjects

Dietary supplements during covid-19 outbreak. Results of google trends analysis supported by plifecovid-19 online studies

Use of vitamin/zinc supplements, medicinal plants, and immune boosting drinks during COVID-19 pandemic: A pilot study from Benha city

COVID-19 disease and nutritional choices: How will the pandemic reconfigure our food psychology and habits? A case study of the Italian population

Risk factors for severe and critically ill COVID-19 patients: A review

The Popularity of the Biologically-Based Therapies During Coronavirus Pandemic Among the Google Users in the USA

The use of dietary supplements among african and caribbean women living in the uk: A cross-sectional study

Dietary supplement use differs by socioeconomic and health-related characteristics among U.S. adults, NHANES 2011-2014

Dietary Supplement Use Among Active Multi-Ethnic Adults

Determinants of supplement usage

Ascorbic acid, neutrophil function, and the immune response

Vitamin C for preventing and treating the common cold

Effect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction among Ambulatory Patients with SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical Trial

Modest effects of dietary supplements during the COVID-19 pandemic: Insights from 445 850 users of the COVID-19 Symptom Study app

Impact of the vitamin D deficiency on COVID-19 infection and morality in Asian countries

Impact of vitamin D deficiency on COVID-19

Vitamin d supplementation associated to better survival in hospitalized frail elderly covid-19 patients: The geria-covid quasi-experimental study

A systematic review of beliefs involved in the use of complementary and alternative medicine

Why people use herbal medicine: Insights from a focus-group study in Germany

Spices and herbs: Natural sources of antioxidants -A mini review

Coriander (Coriandrum sativum L.) and its bioactive constituents

Complementary and alternative medicine use among outpatients during the 2015 MERS outbreak in South Korea: a cross-sectional study

JOURNAL OF ANALYTICAL SCIENCES AND APPLIED BIOTECHNOLGY Medicinal plants used for the prevention purposes during the covid-19 pandemic in Morocco ARTICLE INFO

Garlic and ginger extracts modulated broiler chicks innate immune responses and enhanced multidrug resistant Escherichia coli O78 clearance

Immunity: Plants as Effective Mediators

Natural products as targeted modulators of the immune system

Body weight perception and weight loss practices among Sri Lankan adults

The authors would express our gratitude towards every participant for their contribution in conducting this research study.

This research study did not receive any funding.

The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

RJ, TVF, PS conceived and designed the online survey questionnaire; disseminated the questionnaire; PS analysed and interpreted the data, TVF and RJ drafted the manuscript. PS revised the manuscript. All authors read and approved the final manuscript.J o u r n a l P r e -p r o o f