Quercetin is a great flavonoid for many reasons: It’s a known anti-histamine. It’s considered essential in anti-aging protocols. It modulates DNA methylation and epigenetic expression. It also may drop blood cholesterol through inhibition of PCSK9. McGill scientists looking at quercetin’s ability to lower cholesterol are also looking at it as a potential antiviral agent. A study is now underway in China looking at quercetin and COVID19. While there are online resources recommending quercetin now, and you may choose to prescribe it to your COVID19 patients or for prevention, know that outcome of the COVID19 trial will not be available for months.
Kara Fitzgerald, ND, received her doctor of naturopathic medicine degree from the National University of Natural Medicine in Portland, Oregon. She completed the first Counsel on Naturopathic Medicine-accredited post-doctorate position in nutritional biochemistry and laboratory science at Metametrix Clinical Laboratory under the direction of Richard Lord, PhD. Her residency was completed at Progressive Medical Center, a large, integrative medical practice in Atlanta, Georgia.
Dr. Fitzgerald is the lead author and editor of Case Studies in Integrative and Functional Medicine and is a contributing author to Laboratory Evaluations for Integrative and Functional Medicine and the Institute for Functional Medicine (IFM)’s Textbook for Functional Medicine. With the Helfgott Research Institute, Dr. Fitzgerald is actively engaged in clinical research on the DNA methylome using a diet and lifestyle intervention developed in her practice. The first publication from the study focuses on reversal of biological aging and was published 04-12-2021 in the journal Aging. She has published a consumer book titled Younger You as well as a companion cookbook, Better Broths and Healing Tonics and has an application-based Younger You Program, based on the study.
Dr. Fitzgerald is on the faculty at IFM, is an IFM Certified Practitioner and lectures globally on functional medicine. She runs a Functional Nutrition Residency program, and maintains a podcast series, New Frontiers in Functional Medicine and an active blog on her website, www.drkarafitzgerald.com. Her clinical practice is in Sandy Hook, Connecticut.
Additional publications
Something to consider: “The flavonoid quercetin has been demonstrated to inhibit transport of ascorbate by SVCT1. Ascorbate transport by the low-affinity, high capacity SVCT1 can be inhibited by as much as 80% in the presence of quercetin, and 100% when sodium was replaced by choline. Please be aware of this important conflict [98]. Quercetin occurring naturally in foods such as onions should not pose an issue as the amounts are not high enough in an average serving to exert true inhibitory effects. Supplementation of quercetin may need to be reconsidered when using oral ascorbic acid during COVID-19 treatment.”
Interesting. That quote is from a blog referencing an old cell and animal study paper. I wouldn’t change my use of quercetin based on those findings at all. But if someone felt particularly anxious about the concurrent use of quercetin and vitamin C, since the study identified the inhibition as short term (ie reversible), one could simply space the two nutrients out. Quercetin is a pretty impressive flavonoid for many reasons, antiviral (and perhaps anti-COVID19- human study happening now) properties being just one. I appreciate you posting this idea, Remy. DrKF https://www.jbc.org/content/277/18/15252
Hello,
You mentioned quercetin for PREVENTATIVE measures of Covid-19.
I have alot of family members on the front line. What is your recommended dose of it for this purpose?
Is it also suitable for children?
Thankyou
Stephanie
Good question, Stephanie. Of course, it’s never been researched as a preventative against COVID19. I would comfortably suggest considering 500mg to 1000mg per day. Perhaps dosing higher with symptoms. We use up to 3000mg- 5000mg for a 1-2 week loading period at the beginning of allergy season, dropping down to a maintenance schedule of 500mg-2000mg after symptoms abate. DrKF
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Something to consider: “The flavonoid quercetin has been demonstrated to inhibit transport of ascorbate by SVCT1. Ascorbate transport by the low-affinity, high capacity SVCT1 can be inhibited by as much as 80% in the presence of quercetin, and 100% when sodium was replaced by choline. Please be aware of this important conflict [98]. Quercetin occurring naturally in foods such as onions should not pose an issue as the amounts are not high enough in an average serving to exert true inhibitory effects. Supplementation of quercetin may need to be reconsidered when using oral ascorbic acid during COVID-19 treatment.”
https://www.evolutamente.it/covid-19-ards-cell-free-hemoglobin-the-ascorbic-acid-connection/?fbclid=IwAR3KzUOfzt8fmwEjS2vB-8ESmXxwZ_bUI8nr1vYGiCFAiVOqBokzlFGdJu0
Interesting. That quote is from a blog referencing an old cell and animal study paper. I wouldn’t change my use of quercetin based on those findings at all. But if someone felt particularly anxious about the concurrent use of quercetin and vitamin C, since the study identified the inhibition as short term (ie reversible), one could simply space the two nutrients out. Quercetin is a pretty impressive flavonoid for many reasons, antiviral (and perhaps anti-COVID19- human study happening now) properties being just one. I appreciate you posting this idea, Remy. DrKF https://www.jbc.org/content/277/18/15252
Hello,
You mentioned quercetin for PREVENTATIVE measures of Covid-19.
I have alot of family members on the front line. What is your recommended dose of it for this purpose?
Is it also suitable for children?
Thankyou
Stephanie
Good question, Stephanie. Of course, it’s never been researched as a preventative against COVID19. I would comfortably suggest considering 500mg to 1000mg per day. Perhaps dosing higher with symptoms. We use up to 3000mg- 5000mg for a 1-2 week loading period at the beginning of allergy season, dropping down to a maintenance schedule of 500mg-2000mg after symptoms abate. DrKF
Now I am taking instead Quercitin EGCG its said that is more potent than Quercitin
What dose do you recomend for a try to have a Covid19 profilaxis??
I am also taking n-acetyl l-cisteine and zinc. Also with an multivimin