Consumers’ Feelings About Meat and Meat Alternatives: Can Framing Influence Perception?
In a recent study, researchers used a mixed-methods approach to examine consumer perceptions of meat and meat alternatives and whether framing products as part of a meal, rather than in isolation, influences consumer perceptions (1). The study findings provide insights into how meat alternative products may be positioned to appeal to various consumer profiles and also provide a basis for further research. The following analysis by a dietetic student looks at the key aspects of this study.
FindingsParticipants were invited via social networking websites to take part in two online surveys on consumers’ perceptions of eight food products (red meat, white meat, fish and seafood, insects, legumes, tofu, seitan and lab-grown meat). The first survey asked participants about their attitudes towards these foods, while the second survey (n=285) evaluated consumers’ attitudes towards meats and meat alternatives when presented as either part of a meal or a stand-alone product. The authors concluded that how these foods are presented alters consumer attitudes towards and possibly the adoption of meat alternatives.
What This Means
The authors suggested that consumers can be categorized into three different consumer profiles based on their feelings towards meat and meat alternative products: individuals uninterested and/or disgusted by meat alternatives due to perceived taste preferences (55.8%); individuals open to meat alternatives due to the perceived health benefits of meat alternatives (26.1%); and individuals who prefer meat alternatives and/or feel disgust towards meat consumption due to ethical concerns (18.1%). These profiles may be useful in targeted meat alternative marketing and promotional initiatives as detailed groupings allow the industry to engage consumer preferences through specific messaging and tactics. The results suggest that when a meat alternative is presented as part of a meal instead of a stand-alone product, it can improve the appeal of meat alternatives and elicit more favourable perceptions across profiles.
The findings presented in this study may not be representative or generalizable to diverse populations given that:
- All study participants self-selected in this study on attitudes about meat alternatives were the same nationality (Portuguese).
- The majority were highly educated, female and residing in urban areas.
- A disproportionate number of participants identified as vegetarians or vegans.
- The questions were about attitudes toward foods without participants being presented with any foods.
- The study relied upon participants’ pre-existing knowledge about the food products included in the surveys.
- The methods used to obtain participants (social networking websites and mailing lists) may have influenced the results.
The study was funded through a grant awarded to Catarina Possidonio by Fundaç˜ao para a Ciˆencia e Tecnologia.
Written by Natalie Johnston, BMOS, BSc Candidate, Brescia College University. Reviewed by Lisa Doerr, MSc, RD and Tanis Fenton, PhD, RD, FDC.
- Possidónio C, Prada M, Graça J, Piazza J. Consumer perceptions of conventional and alternative protein sources: a mixed-methods approach with meal and product framing. Appetite. 2021 Jan;156(104860):1-10. doi.org/10.1016/j.appet.2020.104860. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32916208/
U.S. Report of Heavy Metals in Manufactured Infant Foods
A U.S. report finds heavy metals in manufactured infant foods. Should we be concerned? Are heavy metals present in infant foods at unsafe levels? What should dietitians be advising parents to do? The PEN Team went looking for answers.
The Subcommittee on Economic and Consumer Policy of the U.S. House of Representatives released a report stating that some products and ingredients marketed for infants contained high levels of toxic heavy metals (1). Assuring the safety of infant foods is essential for the healthy development of children, so the PEN Team decided to review the Committee’s report to determine the extent of the toxic heavy metals in foods manufactured for infants.
The heavy metals examined in the report included arsenic, lead, cadmium and mercury (1). These findings were gathered from four food manufacturers’ submitted test results. Looking at Table 1
, arsenic levels in the tested infant food products were found to be as high as 180 parts per billion (ppb), lead as high as 50 ppb, cadmium 344 ppb and mercury, although rare, was as high as 10 ppb.
To determine if the levels of heavy metals were too high, the report presented a number of benchmarks (1). The main benchmark used for each of the heavy metals was the U.S. Food and Drug Administration (FDA) established standards for maximum allowable levels in drinking water (see Table 1
). However, Codex (Food and Agricultural International Food Standards) specifies that the maximum acceptable level for arsenic in food is 20 times the maximum acceptable level in water and for lead the difference is 10 times (2). The PEN Team wonders about using maximum levels for drinking water as the basis of comparison, since Codex guidelines recognize that water levels need to be lower than food, as water is consumed in greater quantities than food (2). We also noticed that none of the food products reported exceeded the Codex maximum levels for these metals in foods (see Table 1
When the PEN Team took a closer look at the Subcommittee’s report, we discovered that most of the testing for heavy metals was on the individual ingredients used to create the infant food products (1). Few finished food products were specifically examined. The ingredient with the highest amount of arsenic was amylase enzyme and the highest amount of lead was in one of the cinnamon samples (1). Both of these ingredients are likely present in very small quantities in foods. Therefore, one cannot generalize the findings of high heavy metal contents of individual ingredients directly to the finished food product because we cannot know how high the true amounts of heavy metals are in infant foods when only the contents of ingredients are reported.
Some ingredients that might be used in larger quantities had high amounts of arsenic (rice is known to accumulate arsenic as the plant grows) (3). For example, samples of organic rice flour from two different food manufacturers had amounts of 570 ppb (Beechnut sample) and 390 ppb (Hain sample) (1). These samples were both high compared to the FDA recommendation of no more than 100 ppb for infant rice/rice products (4) and Codex maximum level of 200 ppb for rice (2). However, those samples were unusually high as 92% of the other rice flour samples had arsenic between 100 and 200 ppb. Foods marketed as “organic” were as high or higher than those produced through conventional agriculture (1).
Table 1: Comparison of the Subcommittee Report Findings with International and U.S. National Guidelines for the Maximum Levels of Heavy Metals for Drinking Water and Foods
In Parts per Billion
Subcommittee Report: Maximum in an Infant Food (1)
Codex: Food Maximum Level (2)
FDA: Food Maximum Level for Infant Food (4)
Codex: Drinking Water Maximum Level (2)
FDA: Drinking Water Maximum Level (4)
100 for infant rice cereals
100 for foods,
200 for grains, 500 for meats
Establishing safety levels of heavy metals in foods is very complex. It requires careful consideration of many factors, including the concentration in the food, the amount consumed and its frequency, and the body size of the consumer (5). For a comprehensive review of the safety of arsenic in infant foods, see the PEN Trending Topic: Do New Parents or Parents-to-be Need to be Concerned About Dietary Arsenic Exposure?
Globally, the concentration of arsenic in rice and rice products is a common concern (5). In contrast to the findings of the Subcommittee report, studies from Health Canada and Food Standards Australia New Zealand found that the arsenic content of rice is lower than maximum permitted levels (6,7). In the U.K. where arsenic in some samples of rice exceeded the European Union Standards, the recommendation is to limit rice fed to infants to 20 g/day (8).
Rice, products made from rice, and fruit juices are foods that are typically higher in arsenic and these foods have historically been recommended or given to young children (5). Current advice is to give young children some meat as a source of easily absorbed iron, to offer a variety of infant cereals and grains, and to limit fruit juice (9). These strategies will help to keep young children’s arsenic intakes lower (5).
Until safe standards are established, the PEN Team recommends:
- People of all ages eat a variety of foods (10).
- Rather than purchasing foods specifically marketed for infants/children, young children's transition to eating a variety of food is best supported through family foods. Infants have difficulty obtaining sufficient iron, so dietitians should emphasize the importance of iron-rich foods (meat, meat alternatives and fortified infant cereals made from a variety of grains) (9).
- Dietitians are also encouraged to advocate for the development of heavy metal national standards for infant foods in all countries, including:
- safe limits determination
- standardization of testing
- transparency and labelling of amounts in manufactured infant foods.
The PEN Team would like to thank Becky Blair for contributing to this Trending Topic.
- Subcommittee on Economic and Consumer Policy. Committee on Oversight and Reform. U.S. House of Representatives. Baby foods are tainted with dangerous levels of arsenic, cadmium, lead and mercury. 2021 Feb 4. Available from: https://oversight.house.gov/sites/democrats.oversight.house.gov/files/2021-02-04%20ECP%20Baby%20Food%20Staff%20Report.pdf
- Food and Agriculture Organization, United Nations. General standard for contaminants and toxins in food and feed (CODEX STAN 193-1995). Adopted in 1995. Revised in 1997, 2006, 2008, 2009. Amendments 2010, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019. Available from: http://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fcodex%252FStandards%252FCXS%2B193-1995%252FCXS_193e.pdf
- U.S. Food and Drug. Arsenic in rice and rice products risk assessment. 2016. Available from: https://www.fda.gov/food/science-research-food/cfsan-risk-safety-assessments (under Downloads)
- U.S. Food and Drug Administration. Metals in your food. 2020 Aug 24. Available from: https://www.fda.gov/food/chemicals-metals-pesticides-food/metals-and-your-food
- Dietitians of Canada. Trending Topic - Do new parents or parents-to-be need to be concerned with dietary arsenic exposure? In Practice-based Evidence in Nutrition [PEN]. May 2018. Available from: https://www.pennutrition.com/resourcestools.aspx?trcatid=496&trid=26806&sr=arseniccbabiedcbabiescbabycbabying. Access by subscription only.
- Canadian Food Inspection Agency. 2011-2013 arsenic speciation in selected foods. 2018 Sep 4. Available from: https://www.inspection.gc.ca/food-safety-for-industry/food-chemistry-and-microbiology/food-safety-testing-bulletin-and-reports/arsenic-speciation-in-selected-foods/eng/1467179764138/1467179789317
- Food Standards Australia New Zealand. Arsenic. January 2020. Available from: https://www.foodstandards.gov.au/consumer/chemicals/arsenic/Pages/default.aspx#:~:text=There%20are%20limits%20in%20the,a%20level%20of%202mg%2Fkg
- Menon M, Sarkar B, Hufton J, Reynold C, Reina V, Young S. Do arsenic levels in rice pose a health risk to the UK population? Ecotoxicol Environ Saf. 2020 Jul 1:197:110601. Available from: https://pubmed.ncbi.nlm.nih.gov/32302858/
- Dietitians of Canada. Infant Nutrition - Complementary Feeding Summary of Recommendations and Evidence. In: Practice-based Evidence in Nutrition [PEN]. 2019 Aug 06. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=2503&trcatid=42&trid=2514 Access by subscription only.
- Dietitians of Canada. International Dietary Guideline Collection. In: Practice-based Evidence in Nutrition [PEN]. 2021 Jan 11. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=3127&trid=19399&trcatid=27 Access by subscription only.
Vitamin D and COVID-19: Do Latest Studies Support Supplementation?
To date, research on vitamin D supplementation and COVID-19 outcomes has been limited, so the PEN Team reviewed two recent studies on vitamin D and COVID-19 to see what, if anything, has changed.
Conversations continue on social media about the potential role of vitamin D supplementation in the prevention and treatment of COVID-19. The PEN Team noticed that a common rationale was that patients with COVID-19 tended to have lower vitamin D status (25(OH)D levels). We decided to take a look at two recent studies that reported this connection to determine if the results support vitamin D supplementation to improve COVID-19 outcomes.
First, we looked at an observational study by De Smet et al. that noted that patients with COVID-19 had progressively lower 25(OH)D levels with more severe COVID respiratory disease (1). The study authors also observed that those with vitamin D deficiency were almost four times more likely to die (adjusted odds ratio [OR] 3.87; 95% confidence interval [CI], 1.30 to 11.55). Vitamin D deficiency was prevalent among the patients with COVID-19 infections, more so among the men (67%) than among the women (47%). These researchers adjusted for several variables that are risk factors for COVID-19 mortality (age, ethnicity, chronic lung disease, coronary artery disease/hypertension, diabetes and extent of lung damage).
From other vitamin D research, we know that the marker for vitamin D status (25(OH)D) can be lowered by infections (2). Therefore, low 25(OH)D levels may not reflect poor vitamin D status in a person with an infection. De Smet et al. were not able to determine whether what looked like a vitamin D deficiency was actually a nutritional deficiency or whether the COVID-19 infection lowered the participants 25(OH)D, making these patients appear to have a vitamin D deficiency (1). For this reason, this observational study does not provide evidence that vitamin D supplementation would be helpful for improving outcomes of a COVID-19 infection.
The second study we examined was a randomized control trial of vitamin D supplementation in people with mild symptomatic and asymptomatic COVID-19 infections. Rastogi et al. randomized 40 people with mild COVID-19 infections to 60,000 IU/day of vitamin D3 or placebo for seven days (3). The researchers observed that more participants in the intervention group became COVID-19 RNA negative before day 21 compared to participants in the control arm (62.5% versus 20.8%, P<0.018). Vitamin D supplementation lowered fibrinogen levels significantly but not the other inflammatory markers (SARS-CoV-2 RNA, D-dimer, procalcitonin CRP and ferritin). These researchers only reported differences in indirect markers (3) and did not report World Health Organization-recommended patient-important outcomes (patient survival and patient health care system use over the course of clinical illness) (4). The PEN Team thinks that this trial does not answer the question of whether vitamin D supplementation improves COVID-19 outcomes.
What This Means
After reviewing these studies, the PEN Team has two key questions:
1. What is the relationship between vitamin D deficiency and COVID-19 severity?
2. What is the impact of vitamin D supplementation on patient-important outcomes, such as disease severity, hospitalization and death?
Before dietitians can make recommendations on the use of vitamin D supplementation to improve COVID-19 outcomes, randomized control trials examining the prevention of COVID-19 (including severe COVID-19) and the treatment of COVID-19 with patient-important outcomes are needed.
- De Smet D, De Smet K, Herroelen P, Gryspeerdt S, Martens GA. Serum 25(OH)D Level on Hospital Admission Associated With COVID-19 Stage and Mortality. Am J Clin Pathol. 2020 Nov 25:aqaa252. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7717135/
- Hernández-Álvarez E, Pérez-Barrios C, Blanco-Navarro I, Pérez-Sacristán B, Donoso-Navarro E, Silvestre RA, et al. Association between 25-OH-vitamin D and C-reactive protein as a marker of inflammation and cardiovascular risk in clinical practice. Ann Clin Biochem. 2019 Jul;56(4):502-7. Available from: https://pubmed.ncbi.nlm.nih.gov/31043057/
- Rastogi A, Bhansali A, Khare N, Suri V, Yaddanapudi N, Sachdeva N, et al. Short term, high-dose vitamin D supplementation for COVID-19 disease: a randomised, placebo-controlled, study (SHADE study). Postgrad Med J. 2020 Nov 12:postgradmedj-2020-139065. Abstract available from: https://pubmed.ncbi.nlm.h.gov/33184146/
- WHO Working Group on the Clinical Characterisation and Management of COVID-19 infection. A minimal common outcome measure set for COVID-19 clinical research. Lancet Infect Dis. 2020 Aug;20(8):e192-e197. Abstract available from https://pubmed.ncbi.nlm.nih.gov/32539990/
USDA Dietary Guidelines
Food Trends in 2021
During the COVID-19 pandemic last year, the interest in personalized nutrition, a healthy gut and the immune system and related nutrients and supplements increased, as did cooking more. These trends appear to be continuing into 2021 based on information from Forbes
and Food Insight
, and in some of the links below. Expect to also see an increase in food costs and more interest in reducing waste and recycling, and support for local businesses.
Check out a few other predictions:
Happy New Year!
Consumption of Ultra-Processed Foods Trending Down But Still High
Ultra-processed foods (UPFs) are back in the news
following the publication of two papers this year, both using dietary 24-hour recall data from the Canadian Community Health Survey (CCHS). One paper compared the intake of UPFs and the nutrition profile of the diet between 2004 and 2015 (sample size of 33,924 for the 2004 survey and 20,080 for the 2015 survey; breastfeeding children excluded) (1). The other paper looked at a cross-section of the 2015 UPF consumption data (sample size of 13,608, aged 19 years or older) with associated health effects (2).
In 2019 the PEN® Team wrote two Trending Topics:
The studies reviewed in these past Trending Topics (from the U.K. and France), along with the new Canadian analyses, all have in common an agreement that UPFs have low overall nutritional quality and that the high UPF consumption is of concern. UPFs are often characterized as convenient and hyper-palatable with attractive packaging (1).
How Was ‘Ultra-Processed Foods’ Defined?
The reported food and drink data by survey participants in both 2005 and 2014 (1,2) was classified into four categories according to NOVA classification
, an internationally recognized system of classifying ingredients related to industrial food processing, based on a thesis presented by researchers at Brazil’s University of São Paolo over 10 years ago (3). Category 4, UPF, was the focus of the studies:
- Unprocessed or minimally processed foods including fresh, frozen or dry fruit, vegetables, nuts, legumes and plain meats and milk
- Processed culinary ingredients including sugar, salt, butter and vegetables oils
- Processed foods like canned fruits and vegetables, artisanal breads and cheeses
- Ultra-processed foods (UPFs) including industrial breads, reconstituted meat products, commercial and soft drinks, confectionary, commercial baked goods, crackers and other salty snacks, sauces, spreads and salad dressings and fast-food and frozen dishes.
What Did the CCHS Analyses Find?
The good news is that some UPF types, particularly beverages, declined between 2004 and 2015 (1). That said, the overall share of UPFs (including soft drinks) in Canada remained high in 2015 and contributed 46% of total daily energy for the overall population (as compared to 48% in 2004) with the highest for children and adolescents at 50% in 2015 (1,2). The high levels of UPF intake estimated in this study (1) are in line with previously reported estimates based on population-representative nutrition data from Canada and other high income nations (42% of total energy intake in Australia to about 57% in the United Kingdom) (1). For adults aged 55 or older, the intake of UPFs shifted upwards from about 42% of total usual energy in 2004 to 45% in 2015 (1). High UPF consumption was associated with less formal education, living in rural areas, people born in Canada and with Indigenous identity (2).
The researchers estimated the association between UPF consumption and morbidities (both self-reported) using multivariable logistic regression models on the 2015 data. They found that Canadian adults consuming the highest amounts of UPFs as a proportion of their energy intake had (2):
- 31% higher odds of obesity
- 37% higher odds of diabetes
- 60% higher odds of high blood pressure, compared to those consuming the least amount.
(Note: making conclusions about causal relationships from cross-sectional analyses should be done with caution.)
What Should Happen Next?
As practitioners, we should continue to promote national healthy eating guideline
recommendations to limit the consumption of highly processed foods and drinks. Repeat analysis of UPF intake over time could also help to inform polices targeting the food environment, such as access to UPFs in publicly funded spaces, labelling and taxation initiatives to guide consumer choice. These analyses can also be used to target public health consumer messaging and media literacy components within nutrition-related programs. Continued research on the associations between UPF intake and risk of morbidities is also needed to better understand whether these relationships are causal and if so how health related behaviours could be modified.
See Additional Content:
- Polsky JY, Moubarac JC, Garriguet D. Consumption of ultra-processed foods in Canada. Health Rep. 2020 Nov 18;31(11):3-15. doi: 10.25318/82-003-x202001100001-eng. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/33205938/
- Nardocci M, Polsky J, Moubarac JC. How ultra-processed foods affect health in Canada. Report prepared for Heart and Stroke. Montréal: TRANSNUT, Department of Nutrition, University of Montreal; June 2019. Available from: https://www.heartandstroke.ca/-/media/pdf-files/canada/media-centre/hs-moubarc-study-june-27-2019.ashx?rev=8ac040d6d03a41209fc6d8353ed325b3&hash=81A02F9268388596BD7089AA9C22419D
- Monteiro CA. Nutrition and health. The issue is not food, nor nutrients, so much as processing. Public Health Nutr. 2009;12(5):729–31. Available from: https://pubmed.ncbi.nlm.nih.gov/19366466/
Could Eating Cabbage and Fermented Vegetables Reduce Severe Outcomes of COVID-19?
During the COVID-19 pandemic you may be getting questions from your clients about how food and nutrients may help prevent or treat the coronavirus. The following analysis by a dietetic student looks at a study in adults related to eating fermented vegetables.
A recent narrative review compared COVID-19 mortality rates between and within countries, with a nutrition lens (1). This review led the authors to hypothesize that the severity of COVID-19 outcomes may be reduced through the consumption of foods such as cabbage and fermented vegetables.
A review of two ecological studies (2,3) suggested that there was a statistically significant association between a higher consumption of cabbage, cucumber and fermented vegetables and lower COVID-19 mortality rates. While there are notable limitations to ecological research (further discussed below), it is biologically plausible that cabbage and fermented vegetables could have a protective role on COVID-19 outcomes. The sulforaphane precursors found in cabbage and the Lactobacillus found in fermented vegetables both activate the nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a regulator of cellular anti-oxidative response (4-6). Nrf2 has been shown to protect against many of the factors that increase the risk of severe COVID-19 outcomes, including insulin resistance, inflammation and endothelial damage (7,8). Microbiome changes of the gut resulting from live bacterial cultures in fermented vegetables might also provide protective measures against COVID-19, although further studies are needed to prove whether this is the case (9,10).
A few limitations must be considered when analyzing this article. First, the authors did not perform a robust systematic review with risk of bias assessments, given the lack of original research on the topic. Additionally, the hypothesis of this review relied heavily on data from two ecological studies (2,3), making ecological fallacy a concern. While data compiled through ecological studies can be useful in showing possible associations between variables, results may be misinterpreted for a number of reasons. Most notably, data used for ecological studies comes from populations, rather than individuals, and as such, may have been impacted by a large number of possible confounding factors. For example, COVID-19 mortality rates could be confounded by location-specific factors such as the pandemic policies in place within each country (11), proportion of frontline workers (12) or levels of chronic disease within the population (13). Furthermore, the two ecological studies (2,3) supporting the hypothesis are preprints and therefore have not yet undergone peer review.
The authors acknowledged that this review was intended to generate hypotheses for future studies. Further research is needed to determine if the consumption of cabbage, cucumber and fermented foods can reduce the severity of outcomes resulting from COVID-19.
Written by Amber Foster, BSc. Reviewed by Justine Horne, PhD, RD and Tanis Fenton, PhD, RD, FDC.
- Bousquet J, Anto JM, Czarlewski W, Haahtela T, Fonseca SC, Iaccarino G, et al. Cabbage and fermented vegetables: from death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID‐19. Allergy. 2020 [Epub ahead of print] doi.org/10.1111/all.14549. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32762135/
- Fonseca S, Rivas I, Romaguera D, Quijal M, Czarlewski W, Vidal A, et al. Association between consumption of fermented vegetables and COVID‐19 mortality at a country level in Europe. medRxiv. 2020. doi.org/10.1101/2020.07.06.20147025. Abstract available from: https://www.medrxiv.org/content/10.1101/2020.07.06.20147025v1
- Fonseca SC, Rivas I, Romaguera D, Quijal-Zamorano M, Czarlewski W, Vidal A, et al. Association between consumption of vegetables and COVID‐19 mortality at a country level in Europe. medRxiv. 2020. doi.org/10.1101/2020.07.17.20155846. Available from: https://www.medrxiv.org/content/10.1101/2020.07.17.20155846v1
- Luang‐In V, Deeseenthum S, Udomwong P, Saengha W, Gregori M. Formation of sulforaphane and iberin products from thai cabbage fermented by myrosinase ‐ positive bacteria. Molecules. 2018;23(4):955. doi: 10.3390/molecules2304095. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/29671807/
- Yang L, Palliyaguru DL, Kensler TW. Frugal chemoprevention: targeting Nrf2 with foods rich in sulforaphane. Semin Oncol. 2016;43(1):146‐53. doi: 10.1053/j.seminoncol.2015.09.013. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/26970133/
- Senger DR, Li D, Jaminet SC, Cao S. Activation of the Nrf2 Cell defense pathway by ancient foods: disease prevention by important molecules and microbes lost from the modern western diet. PLoS One. 2016;11:e0148042. doi: 10.1371/journal.pone.0148042. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/26885667/
- Chen B, Lu Y, Chen Y, Cheng J. The role of Nrf2 in oxidative stress‐induced endothelial injuries. J Endocrinol. 2015;225(3):R83‐99. doi: 10.1530/JOE-14-0662. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/25918130/
- Xu L, Nagata N, Ota T. Glucoraphanin: a broccoli sprout extract that ameliorates obesity‐induced inflammation and insulin resistance. Adipocyte. 2018;7(3):218‐25. doi:10.1080/21623945.2018.1474669. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/29898626/
- Saad MJ, Santos A, Prada PO. Linking gut microbiota and inflammation to obesity and insulin resistance. Physiology. 2016;31(4):283‐293. doi: 10.1152/physiol.00041.2015. Available from: https://pubmed.ncbi.nlm.nih.gov/27252163/
- Zuo T, Zhang F, Lui GCY, Yeoh YK, Li AYL, Zhan H, et al. Alterations in gut microbiota of patients with COVID‐19 during time of hospitalization. Gastroenterology. 2020;159(3):944-55.e8. doi: 10.1053/j.gastro.2020.05.048. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32442562/
- Roser M, Ritchie H, Ortiz-Ospina E, Hasell, J. Policy responses to the coronavirus pandemic. Our World in Data: Oxford (UK): 2020. Available from: https://ourworldindata.org/policy-responses-covid
- Nguyen LH, Drew DA, Graham MS, Joshi, AD, Chuan-Gou G, Ma W, et al. Risk of COVID-19 among front-line health-care workers and the general community: a prospective cohort study. Lancet. 2020 Sep;5(9):475-43. doi: 10.1016/S2468-2667(20)30164-X. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32745512/
- Sanyaolu A, Okorie C, Marinkovic A, Patidar R, Younis K, Desai P, et al. Comorbidity and its impact on patients with COVID-19. SN Compr Clin Med. 2020 Jun:1-8. doi: 10.1007/s42399-020-00363-4. Epub ahead of print. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/32838147/
Should I Recommend Vitamin D Supplements to Protect Against COVID-19? Updated November 2020
The Bottom Line:
- No studies have examined the effect of vitamin D to prevent or treat COVID-19 infections.
- Information extrapolated from randomized trials that examined respiratory tract infection prevention have not reported consistent beneficial effects of vitamin D compared to placebo in adults or children.
- Potential risks that have been identified include a higher rate of repeat episodes of pneumonia.
- While observational studies suggest that lower serum vitamin D levels are associated with inflammatory response, lower serum vitamin D levels are associated with other factors and not only with inadequate vitamin D intake.
- Vitamin D is an essential nutrient and vitamin D supplementation is recommended in a number of countries for various ages during the life cycle for general health.