COVID-19: Eating for Immunity
March 25, 2020
Rhya Pachin, RDN, LDN, CLT

Confused about what supplements to take? Concerned about safety? Are the same supplements helpful for prevention also safe during infection?


First off, let’s keep in mind that COVID-19 is a new strain of an existing virus type so we don’t have solid clinical human trials to lean on. However, I also don’t think that means we should do nothing or write off all supplements as unnecessary and ineffective. We can use information we know about similar viruses, the immune system in general, and some limited in vitro evidence to proactively determine possible opportunities for additional immune support from supplements. We know that a dramatic increase in inflammatory chemicals called cytokines can contribute to a severe response to the virus. So let’s talk evidence as far as what’s working and what’s not prior to, and even during infection.


Supplements considered safe for prevention AND during infection:

  • Zinc: based on limited evidence, it appears that zinc may inhibit viral entry into cells. A dose of 15-30mg per day is considered safe and adequate. Higher doses can be taken short-term for several weeks, but prolonged high doses can deplete copper levels.
  • Vitamin C: Clinical trials have shown that Vitamin C can reduce the incidence of pneumonia, and may offer general immune support. Typical dosing in studies ranges from 500-3000mg per day. Note Vitamin C is water-soluble so the body cannot absorb large amounts at one time. It is suggested to spread out doses throughout the day.
  • Garlic: has known antiviral properties and stimulates the immune system while reducing cytokine activation.
  • Bioflavonoids: There was a very recent preliminary study indicating that certain plant compounds such as quercetin, have been shown to reduce inflammatory signaling associated with viral activation. More studies are needed, but in the meantime this brings me to an important point that while we seek to better understand which supplements might offer additional protection-- fruits and vegetables have always contained these powerful compounds!



Supplements potentially counter-productive during infection (but still helpful for prevention):

  • Vitamin A: early studies show conflicting results regarding high doses of Vitamin A and its effect on COVID-19, so high and prolonged doses may not be helpful.
  • Vitamin D: has always been a go-to in my nutritional toolbox because so many people are deficient and every organ in the body uses it. However, new evidence suggests that if COVID-19 is contracted then high doses of Vitamin D may hurt more than it helps. Therefore, consider a moderate dose of Vitamin D, such as 1000-2000 IU per day for prevention, and consider discontinuing in case of a positive COVID test.
  • Elderberry: This is another one of my favorites that again appears to be helpful in prevention and early stages of virus infection, but not in the later stages, so consider that if any symptoms of infection occur.
  • Echinacea: may stimulate the immune system in a way that activates cytokines.
  • Again, these supplements can still be helpful for general cold and flu prevention, but because a person’s susceptibility to experiencing a cytokine storm is difficult to predict at this point, large doses and/or prolonged use may not be encouraged if infected with COVID-19.


My whole point in talking about this today is to bring attention to one very important pattern: notice anything in common with the first list? They are all found in food! So if you don’t have access to high-quality supplements or find this overwhelming, make sure you are at least consuming fruits and vegetables on a daily basis, at least 5 servings per day, but preferably 7-10. And on that note, I’d like to invite you to a free webinar beginning tomorrow, Wed March 25th to learn more specifically about Eating for Immunity. You can access it on the website under Services/Webinar Access Page. Join me and my new partner Sandy as she walks us through what foods to incorporate and what foods to avoid in order to best support our immune system for the weeks and months to come.


References:

1. Choe J-Y, et al. Quercetin and Ascorbic Acid Suppress Fructose-Induced NLRP3 Inflammasome Activation by Blocking Intracellular Shuttling of TXNIP in Human Macrophage Cell Lines. Inflammation. 2017;40(3):980.

2. Choe J-Y, et al. Quercetin and Ascorbic Acid Suppress Fructose-Induced NLRP3 Inflammasome Activation by Blocking Intracellular Shuttling of TXNIP in Human Macrophage Cell Lines. Inflammation. 2017;40(3):980. 19

3. Hemila, H. Vitamin C Supplementation and Respiratory Infections: A Systematic Review. Mil Med. 2004;169(11):90.

4. Antiviral Activity of Sambucus FormosanaNakai Ethanol Extract and Related Phenolic Acid Constituents Against Human Coronavirus NL63. Virus Res. 2019;273:197767.

5. Chen C, et al. Sambucus Nigra Extracts Inhibit Infectious Bronchitis Virus at an Early Point During Replication. BMC Vet Res. 2014:10:24.

6. Barak V, et al. The Effect of Sambucol, a Black Elderberry-Based, Natural Product, on the Production of Human Cytokines: I. Inflammatory Cytokines. Eur Cytokine Netw. 2001;12(2):290.

7. Ulbricht C, et al. An Evidence-Based Systematic Review of Elderberry and Elderflower (Sambucus nigra) by the Natural Standard Research Collaboration. J Dietary Suppl. 2014;11(1):80.

8. Burger RA, et al. Echinacea-induced Cytokine Production by Human Macrophages. Int J Immunopharmacol. 1997;19(7):371.

9. Senchina DS, et al. Human Blood Mononuclear Cell in Vitro Cytokine Response Before and After Two Different Strenuous Exercise Bouts in the Presence of Bloodroot and Echinacea Extracts. Blood Cells Mol Dis. 2009;43(3):298.

10. Verway M, et al. Vitamin D Induces interleukin-1β Expression: Paracrine Macrophage Epithelial Signaling Controls M. Tuberculosis Infection. PLoS Pathog. 2013;9(6):e1003407.

11. Arreola R, et al. Immunodulation and Anti-Inflammatory Effects of Garlic Compounds. J Immunol Res. 2015;2015:401630.

12. Micek J, et al. Quercetin and Its Anti-Allergic Immune Response. Molecules. 2016;21(5):623.

13. Ulbricht C, et al. An Evidence-Based Systematic Review of Elderberry and Elderflower (Sambucus Nigra) by the Natural Standard Research Collaboration. J Diet Suppl. 2014;11(1):80.

14.Han Y-S, et al. Papain-like Protease 2 (PLP2) From Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV): Expression, Purification, Characterization, and Inhibition. Biochemistry. 2005;44(30):10349.

15. Farhangi MA, et al. Vitamin A Supplementation and Serum Th1- And Th2-associated Cytokine Response in Women. J Am Coll Nutr. 2013;32(4):280.

16. Penniston KL and Tanumihardjo SA. The acute and chronic toxic effects of vitamin A. Am J Clin Nutr. 2006; 83(23):191.

17.Choe J-Y, et al. Quercetin and Ascorbic Acid Suppress Fructose-Induced NLRP3 Inflammasome Activation by Blocking Intracellular Shuttling of TXNIP in Human Macrophage Cell Lines. Inflammation. 2017;40(3):980.

By Rhya Pachin • October 6, 2026
An Organic Acids Test (OAT) is a urine-based laboratory test that measures a range of organic-acid metabolites , which are byproducts of normal metabolism. Depending on the specific OAT used, the markers can provide information about areas such as energy production, nutrient-related metabolism, oxidative stress, and microbial activity. Vibrant Wellness and MosaicDX both offer OATs, although the exact markers and reporting vary between laboratories. An OAT can be a useful piece of information for some people, but it is not a test that everyone needs. At Carolina Functional Nutrition, testing is selected based on the individual, their symptoms and history, and the clinical question we are trying to answer. - - - - - - Organic Acid Testing: Key Points OAT is a urine test: An Organic Acids Test measures organic-acid metabolites in a urine sample. These compounds are produced through metabolic processes and are excreted in urine. It looks at multiple pathways: Depending on the laboratory, an OAT may include markers related to energy and mitochondrial metabolism, nutrient-related pathways, microbial activity, neurotransmitter metabolism, and oxidative stress. The exact panel varies, so two OATs should not automatically be treated as identical. It is not a standalone diagnosis: An abnormal marker does not automatically tell you what condition you have or what treatment you need. Results need to be considered alongside symptoms, medical history, medications, nutrition, and other relevant testing. Testing should have a purpose: An OAT is most useful when the results could add meaningful information to a specific clinical question. More testing is not necessarily better testing. Preparation matters: Diet, medications, supplements, hydration, timing, and other factors can influence organic-acid results. Your provider or laboratory should give you specific collection instructions. The test is only one piece of the picture: An OAT does not replace appropriate medical evaluation or standard laboratory testing when those are indicated. In some situations, other or more targeted testing may be more appropriate. - - - - - - Understanding Organic Acids Testing The term “organic acids” refers to a broad group of compounds produced during normal metabolism. Your body creates and breaks down these compounds as it processes carbohydrates, fats, amino acids, nutrients, and other substances. Many are ultimately excreted in urine. A commercial OAT brings a number of these markers together into one urine panel. For example, the current Vibrant Wellness OAT includes markers related to metabolic and mitochondrial function, microbial and gut health, neurotransmitter and brain function, and detoxification, nutritional, and oxidative-stress pathways. MosaicDX describes its OAT as measuring 76 organic acids from a urine sample across several metabolic categories. That does not mean an OAT can tell you exactly why you have a particular symptom. Instead, the results may p rovide additional information that can be considered alongside the rest of your health picture . For example, someone dealing with persistent fatigue may have several possible contributors worth considering, including sleep, nutrition, blood sugar regulation, thyroid function, medications, digestive health, or other medical conditions. An OAT may be useful in some cases, but it would not automatically be the next step for every person with fatigue. This is why personalized testing matters. The same symptom can have very different contributors from one person to another. - - - - - - How OAT Results Are Evaluated IAn OAT generally requires a urine sample. Both Vibrant Wellness and MosaicDX describe their OATs as urine-based tests, with collection instructions provided for the specific laboratory's kit. The exact preparation instructions can vary. For example, Vibrant Wellness recommends a first-morning urine collection and provides guidance around fasting, hydration, medications, supplements, certain foods, and other factors that may affect the sample. The laboratory specifically advises patients to follow their provider's instructions rather than independently stopping prescribed medications. Once the sample is processed, the report provides results for the markers included in that particular panel. The next step is interpretation. This is an important part of the process. A result should not be viewed in isolation and turned into a supplement recommendation simply because one marker falls outside a reference range. Organic-acid profiles can be influenced by diet, medications, clinical state, and other factors, and interpretation depends on the overall pattern and clinical context. At Carolina Functional Nutrition, we use testing to help answer questions —not to create a longer list of things to “fix.” The goal is to understand whether the information from an OAT adds something useful to the rest of the evaluation. - - - - - - Who May Benefit From an Organic Acids Test An OAT may be considered for an adult or child when the symptoms, history, and clinical question make the information potentially useful. It may be particularly relevant when someone has a more complex or multi-system symptom picture and a practitioner is trying to better understand certain metabolic or nutritional patterns. That does not mean an OAT is automatically appropriate for fatigue, digestive problems, brain fog, mood changes, or other common symptoms. Those symptoms have many possible explanations, and testing should be selected based on the individual rather than the symptom alone. You should also be cautious about ordering an OAT simply because you saw a list of symptoms online and recognized yourself in it. A test result without appropriate interpretation can create confusion, unnecessary worry, or an overly restrictive treatment plan. People with significant medical conditions, complex medication regimens, or concerning symptoms may also need evaluation through their physician or an appropriate medical specialist. Functional nutrition can complement conventional medical care; it should not replace necessary diagnosis or treatment. For someone in Charlotte, NC—or working with a provider virtually—the important question is not simply, “Can I get an OAT?” It is, “Would this test add useful information for my situation?” - - - - - - Risks, Limitations & What to Monitor An OAT is generally noninvasive because it involves urine collection rather than a blood draw. The bigger considerations are usually related to preparation, interpretation, cost, and what you do with the information afterward. Preparation requirements: Depending on the laboratory, you may receive instructions about fasting, hydration, foods, supplements, medications, exercise, or the timing of your urine collection. Following the laboratory's instructions matters because diet, medications, supplements, and other factors can affect organic-acid results. Results can be nonspecific: An elevated or decreased marker does not necessarily point to one single cause. Organic-acid profiles can be affected by nutritional, medication-related, physiologic, and other factors, which is one reason results should be interpreted in context. Different labs measure different things: Vibrant Wellness and MosaicDX do not report exactly the same panel. The number and type of markers can vary between laboratories, so it is important to know which test was ordered and what its specific markers are. More information can sometimes mean more confusion: If testing is ordered without a clear clinical question, an unexpected result may lead to unnecessary supplements, dietary restrictions, or additional testing. The purpose of testing should be to clarify the plan, not simply to generate more data. Follow-up matters: If an OAT is used as part of your evaluation, the results should be considered alongside your symptoms and other relevant information. Depending on what is found, your practitioner may recommend no additional testing, a more targeted test, coordination with your physician, or a nutrition and lifestyle plan. - - - - - - When To Seek Care An OAT is not designed to replace evaluation for urgent or potentially serious symptoms. Seek prompt medical attention for symptoms such as severe or worsening abdominal pain, significant or persistent vomiting, blood in the stool, fainting, severe dehydration, new confusion, chest pain, difficulty breathing, or sudden weakness or numbness. If you have persistent symptoms that are affecting your daily life but are not an emergency, bring them to the attention of your primary-care clinician or another qualified healthcare professional. An OAT may or may not be appropriate depending on what is happening and what other evaluation has already been completed. - - - - - - Next Steps If you are wondering whether an Organic Acids Test could be useful for you, the best place to start is with your individual symptoms, history, and goals rather than ordering a test based on a general recommendation. At Carolina Functional Nutrition, we use personalized testing when it can help clarify the bigger picture and guide next steps. If you’re in Charlotte, NC, or working with us virtually, you can Book a discovery call to talk through whether our approach is a good fit. You can also learn more about our functional nutrition services . Testing is only one part of the process; the goal is to understand what information is actually useful for you. - - - - - - Sources & Citations GOrganic Acids Test – Vibrant Wellness How Should Patients Prepare for the Organic Acids Test? – Vibrant Wellness Organic Acids Test (OAT) – MosaicDX Laboratory analysis of organic acids, 2018 update: a technical standard of the American College of Medical Genetics and Genomics – Genetics in Medicine Organic Acids Screen, Urine Spot – Mayo Clinic Laboratories Medically reviewed by Rhya Pachin, MS, RDN, LDN, CLT Last updated: October 6, 2026 This content is for educational purposes and does not substitute personalized medical advice.
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About the Author

Rhya Pachin is a licensed dietitian nutritionist who employs an "integrative" approach to support overall health rather than addressing just one symptom. As a certified LEAP therapist, she designs and supervises custom elimination diets. Her focus areas include gastrointestinal conditions like IBS and IBD, autoimmune diseases such as rheumatoid arthritis and Hashimoto's, persistent weight issues, food sensitivities, and chronic inflammatory conditions in both adults and children.

By Rhya Pachin • October 6, 2026
An Organic Acids Test (OAT) is a urine-based laboratory test that measures a range of organic-acid metabolites , which are byproducts of normal metabolism. Depending on the specific OAT used, the markers can provide information about areas such as energy production, nutrient-related metabolism, oxidative stress, and microbial activity. Vibrant Wellness and MosaicDX both offer OATs, although the exact markers and reporting vary between laboratories. An OAT can be a useful piece of information for some people, but it is not a test that everyone needs. At Carolina Functional Nutrition, testing is selected based on the individual, their symptoms and history, and the clinical question we are trying to answer. - - - - - - Organic Acid Testing: Key Points OAT is a urine test: An Organic Acids Test measures organic-acid metabolites in a urine sample. These compounds are produced through metabolic processes and are excreted in urine. It looks at multiple pathways: Depending on the laboratory, an OAT may include markers related to energy and mitochondrial metabolism, nutrient-related pathways, microbial activity, neurotransmitter metabolism, and oxidative stress. The exact panel varies, so two OATs should not automatically be treated as identical. It is not a standalone diagnosis: An abnormal marker does not automatically tell you what condition you have or what treatment you need. Results need to be considered alongside symptoms, medical history, medications, nutrition, and other relevant testing. Testing should have a purpose: An OAT is most useful when the results could add meaningful information to a specific clinical question. More testing is not necessarily better testing. Preparation matters: Diet, medications, supplements, hydration, timing, and other factors can influence organic-acid results. Your provider or laboratory should give you specific collection instructions. The test is only one piece of the picture: An OAT does not replace appropriate medical evaluation or standard laboratory testing when those are indicated. In some situations, other or more targeted testing may be more appropriate. - - - - - - Understanding Organic Acids Testing The term “organic acids” refers to a broad group of compounds produced during normal metabolism. Your body creates and breaks down these compounds as it processes carbohydrates, fats, amino acids, nutrients, and other substances. Many are ultimately excreted in urine. A commercial OAT brings a number of these markers together into one urine panel. For example, the current Vibrant Wellness OAT includes markers related to metabolic and mitochondrial function, microbial and gut health, neurotransmitter and brain function, and detoxification, nutritional, and oxidative-stress pathways. MosaicDX describes its OAT as measuring 76 organic acids from a urine sample across several metabolic categories. That does not mean an OAT can tell you exactly why you have a particular symptom. Instead, the results may p rovide additional information that can be considered alongside the rest of your health picture . For example, someone dealing with persistent fatigue may have several possible contributors worth considering, including sleep, nutrition, blood sugar regulation, thyroid function, medications, digestive health, or other medical conditions. An OAT may be useful in some cases, but it would not automatically be the next step for every person with fatigue. This is why personalized testing matters. The same symptom can have very different contributors from one person to another. - - - - - - How OAT Results Are Evaluated IAn OAT generally requires a urine sample. Both Vibrant Wellness and MosaicDX describe their OATs as urine-based tests, with collection instructions provided for the specific laboratory's kit. The exact preparation instructions can vary. For example, Vibrant Wellness recommends a first-morning urine collection and provides guidance around fasting, hydration, medications, supplements, certain foods, and other factors that may affect the sample. The laboratory specifically advises patients to follow their provider's instructions rather than independently stopping prescribed medications. Once the sample is processed, the report provides results for the markers included in that particular panel. The next step is interpretation. This is an important part of the process. A result should not be viewed in isolation and turned into a supplement recommendation simply because one marker falls outside a reference range. Organic-acid profiles can be influenced by diet, medications, clinical state, and other factors, and interpretation depends on the overall pattern and clinical context. At Carolina Functional Nutrition, we use testing to help answer questions —not to create a longer list of things to “fix.” The goal is to understand whether the information from an OAT adds something useful to the rest of the evaluation. - - - - - - Who May Benefit From an Organic Acids Test An OAT may be considered for an adult or child when the symptoms, history, and clinical question make the information potentially useful. It may be particularly relevant when someone has a more complex or multi-system symptom picture and a practitioner is trying to better understand certain metabolic or nutritional patterns. That does not mean an OAT is automatically appropriate for fatigue, digestive problems, brain fog, mood changes, or other common symptoms. Those symptoms have many possible explanations, and testing should be selected based on the individual rather than the symptom alone. You should also be cautious about ordering an OAT simply because you saw a list of symptoms online and recognized yourself in it. A test result without appropriate interpretation can create confusion, unnecessary worry, or an overly restrictive treatment plan. People with significant medical conditions, complex medication regimens, or concerning symptoms may also need evaluation through their physician or an appropriate medical specialist. Functional nutrition can complement conventional medical care; it should not replace necessary diagnosis or treatment. For someone in Charlotte, NC—or working with a provider virtually—the important question is not simply, “Can I get an OAT?” It is, “Would this test add useful information for my situation?” - - - - - - Risks, Limitations & What to Monitor An OAT is generally noninvasive because it involves urine collection rather than a blood draw. The bigger considerations are usually related to preparation, interpretation, cost, and what you do with the information afterward. Preparation requirements: Depending on the laboratory, you may receive instructions about fasting, hydration, foods, supplements, medications, exercise, or the timing of your urine collection. Following the laboratory's instructions matters because diet, medications, supplements, and other factors can affect organic-acid results. Results can be nonspecific: An elevated or decreased marker does not necessarily point to one single cause. Organic-acid profiles can be affected by nutritional, medication-related, physiologic, and other factors, which is one reason results should be interpreted in context. Different labs measure different things: Vibrant Wellness and MosaicDX do not report exactly the same panel. The number and type of markers can vary between laboratories, so it is important to know which test was ordered and what its specific markers are. More information can sometimes mean more confusion: If testing is ordered without a clear clinical question, an unexpected result may lead to unnecessary supplements, dietary restrictions, or additional testing. The purpose of testing should be to clarify the plan, not simply to generate more data. Follow-up matters: If an OAT is used as part of your evaluation, the results should be considered alongside your symptoms and other relevant information. Depending on what is found, your practitioner may recommend no additional testing, a more targeted test, coordination with your physician, or a nutrition and lifestyle plan. - - - - - - When To Seek Care An OAT is not designed to replace evaluation for urgent or potentially serious symptoms. Seek prompt medical attention for symptoms such as severe or worsening abdominal pain, significant or persistent vomiting, blood in the stool, fainting, severe dehydration, new confusion, chest pain, difficulty breathing, or sudden weakness or numbness. If you have persistent symptoms that are affecting your daily life but are not an emergency, bring them to the attention of your primary-care clinician or another qualified healthcare professional. An OAT may or may not be appropriate depending on what is happening and what other evaluation has already been completed. - - - - - - Next Steps If you are wondering whether an Organic Acids Test could be useful for you, the best place to start is with your individual symptoms, history, and goals rather than ordering a test based on a general recommendation. At Carolina Functional Nutrition, we use personalized testing when it can help clarify the bigger picture and guide next steps. If you’re in Charlotte, NC, or working with us virtually, you can Book a discovery call to talk through whether our approach is a good fit. You can also learn more about our functional nutrition services . Testing is only one part of the process; the goal is to understand what information is actually useful for you. - - - - - - Sources & Citations GOrganic Acids Test – Vibrant Wellness How Should Patients Prepare for the Organic Acids Test? – Vibrant Wellness Organic Acids Test (OAT) – MosaicDX Laboratory analysis of organic acids, 2018 update: a technical standard of the American College of Medical Genetics and Genomics – Genetics in Medicine Organic Acids Screen, Urine Spot – Mayo Clinic Laboratories Medically reviewed by Rhya Pachin, MS, RDN, LDN, CLT Last updated: October 6, 2026 This content is for educational purposes and does not substitute personalized medical advice.
A woman in a white robe touches her face and looks at herself in a circular, wall hanging mirror
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A spread of prepared foods across a wooden dinner table from a flat-lay perspective
By Rhya Pachin • September 2, 2026
Wondering if a food is causing your symptoms? Learn how food sensitivities differ from allergies and how to identify potential food triggers.
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