Vitamin C (as Ascorbic Acid), Zinc (as Zinc Amino Acid Chelate), Citrus Bioflavonoid Complex: Grapefruit Powder (Fruit), Lemon Powder (Peel), Orange Powder (Fruit), Quercetin Dihydrate, Rose Hips Extract (Rosa canina) (Fruit), Elderberry Extract (Fruit; Std. to 5% Flavanoids). Other Ingredients: Methylcellulose Capsule.

Adults take 2 capsules daily with 8 ounces of water or your favorite beverage.  May be taken with or without food.

CAUTION: Do not exceed recommended dose. Please use caution if you have allergies or sensitivities to any of the listed ingredients. Pregnant or nursing mothers and individuals with a known medical condition should consult a physician before using this or any dietary supplement. Use only as directed. If gastrointestinal discomfort (including bloating, cramps, diarrhea, or other digestive upset) or other sensitivity is experienced stop taking the product immediately. If you are pregnant, nursing, or have a medical condition, please consult with your physician before use. If you have any questions about consuming this dietary supplement, consult with your health care professional before using. If you use prescription drugs or over-the-counter medications, are unaware of your current medical condition or have a pre-existing medical condition(s), consult with your health care professional before using. Discontinue use immediately if you experience any adverse symptoms or reactions while taking this product. Discontinue use 2 weeks prior to surgery. Do not use if your health status is unknown. Do not use if safety seal is damaged or missing. Keep out of reach of children and pets. Store in a cool, dry place, away from heat moisture. Use this product as a food supplement only. Do not use for weight reduction.

Vitamin C Complex

Chambial S, Dwivedi S, Shukla KK, John PJ, Sharma P. Vitamin C in disease prevention and cure: an overview. Indian J Clin Biochem. 2013;28(4):314‐328.  doi: 10.1007/s12291-013-0375-3

Traber MG, Stevens JF. Vitamins C and E: beneficial effects from a mechanistic perspective. Free Radic Biol Med. 2011;51(5):1000‐1013. doi: 10.1016/j.freeradbiomed.2011.05.017

Padayatty, S. J., Katz, A., Wang, Y., Eck, P., Kwon, O., Lee, J. H., Chen, S., Corpe, C., Dutta, A., Dutta, S. K., & Levine, M. (2003). Vitamin C as an antioxidant: evaluation of its role in disease prevention. Journal of the American College of Nutrition, 22(1), 18–35. DOI: 10.1080/07315724.2003.10719272

Pehlivan, Fadime. (2017). Vitamin C: An Antioxidant Agent. 10.5772/intechopen.69660. DOI: 10.5772/intechopen.69660

A. Bendich, L.J. Machlin, O. Scandurra, G.W. Burton, D.D.M. Wayner, The antioxidant role of vitamin C, Advances in Free Radical Biology & Medicine, Volume 2, Issue 2, 1986, 419-444, 8755-9668. https://doi.org/10.1016/S8755-9668(86)80021-7

Marc Bürzle, Matthias A. Hediger. Chapter Eleven: Functional and Physiological Role of Vitamin C Transporters. Mark O. Bevensee. Current Topics in Membranes. Academic Press. 70. 2012. 357-375. 1063-5823. 9780123943163. https://doi.org/10.1016/B978-0-12-394316-3.00011-9

Akbari, Abolfazl & Jelodar, Gholamali & Nazifi, Saeed & Sajedianfard, Javad. (2016). An Overview of The characteristics and Function of Vitamin C in Various Tissues: Relying on its Antioxidant Function. Zahedan Journal of Research in Medical Sciences. In Press. DOI: 10.17795/zjrms-4037

Chakraborthy, Aratirika & Ramani, Pratibha & Sherlin, Herald & Premkumar, Priya & Natesan, Anuja. (2014). Antioxidant and pro-oxidant activity of Vitamin C in oral environment. Indian journal of dental research : official publication of Indian Society for Dental Research. 25. 499-504. DOI: 10.4103/0970-9290.142547

Sirmali, Rana & Giniş, Zeynep & Sirmali, Mehmet & Solak, Okan & Şeliman, Bengü & Ağaçkiran, Yetkin & Delibaş, Namık. (2014). Vitamin C as an antioxidant: evaluation of its role on pulmonary contusion experimental model. Turkish journal of medical sciences. 44. 905-13. DOI: 10.3906/sag-1309-139

Citrus Bioflavonoids

Stevens, Y., Rymenant, E. V., Grootaert, C., Camp, J. V., Possemiers, S., Masclee, A., & Jonkers, D. (2019). The Intestinal Fate of Citrus Flavanones and Their Effects on Gastrointestinal Health. Nutrients, 11(7), 1464. DOI: 10.3390/nu11071464

Testai L, Calderone V. Nutraceutical Value of Citrus Flavanones and Their Implications in Cardiovascular Disease. Nutrients. 2017;9(5):502. Published 2017 May 16. doi: 10.3390/nu9050502

Barreca, D., Gattuso, G., Bellocco, E., Calderaro, A., Trombetta, D., Smeriglio, A., Laganà, G., Daglia, M., Meneghini, S., & Nabavi, S. M. (2017). Flavanones: Citrus phytochemical with health-promoting properties. BioFactors (Oxford, England), 43(4), 495–506. DOI: 10.1002/biof.1363

Sharma, M., Akhtar, N., Sambhav, K., Shete, G., Bansal, A. K., & Sharma, S. S. (2015). Emerging potential of citrus flavanones as an antioxidant in diabetes and its complications. Current topics in medicinal chemistry, 15(2), 187–195. DOI: 10.2174/1568026615666141209163013

Chanet, A., Milenkovic, D., Manach, C., Mazur, A., & Morand, C. (2012). Citrus flavanones: what is their role in cardiovascular protection?. Journal of agricultural and food chemistry, 60(36), 8809–8822. DOI: 10.1021/jf300669s

Zaidun, N. H., Thent, Z. C., & Latiff, A. A. (2018). Combating oxidative stress disorders with citrus flavonoid: Naringenin. Life sciences, 208, 111–122. DOI: 10.1016/j.lfs.2018.07.017

Assini, J. M., Mulvihill, E. E., & Huff, M. W. (2013). Citrus flavonoids and lipid metabolism. Current opinion in lipidology, 24(1), 34–40. DOI: 10.1097/MOL.0b013e32835c07fd

Asgary, S., Naderi, G., & Askari, N. (2005). Protective effect of flavonoids against red blood cell hemolysis by free radicals. Experimental and clinical cardiology, 10(2), 88–90. PMCID: PMC2716227

Elderberry Powder

Sidor, Andrzej & Gramza Michalowska, Anna. (2014). Advanced research on the antioxidant and health benefit of elderberry (Sambucus nigra) in food – a review. Journal of Functional Foods. 18. DOI: 10.1016/j.jff.2014.07.012

Porter, R. S., & Bode, R. F. (2017). A Review of the Antiviral Properties of Black Elder (Sambucus nigra L.) Products. Phytotherapy research : PTR, 31(4), 533–554. DOI: 10.1002/ptr.5782

Zakay-Rones, Z., Thom, E., Wollan, T., & Wadstein, J. (2004). Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. The Journal of international medical research, 32(2), 132–140. DOI: 10.1177/147323000403200205

Barak, V., Halperin, T., & Kalickman, I. (2001). The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. European cytokine network, 12(2), 290–296. PMID: 11399518

Hawkins, J., Baker, C., Cherry, L., & Dunne, E. (2019). Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials. Complementary therapies in medicine, 42, 361–365. DOI: 10.1016/j.ctim.2018.12.004

Tiralongo E, Wee SS, Lea RA. Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial. Nutrients. 2016;8(4):182. Published 2016 Mar 24. doi: 10.3390/nu8040182

Porter, R. S., & Bode, R. F. (2017). A Review of the Antiviral Properties of Black Elder (Sambucus nigra L.) Products. Phytotherapy research : PTR, 31(4), 533–554. DOI: 10.1002/ptr.5782

Quercetin

Selamoglu, Zeliha. (2016). Antioxidant Activity of Quercetin: A Mechanistic Review. Turkish Journal of Agriculture - Food Science and Technology. 4. 10.24925/turjaf.v4i12.1134-1138.1069. DOI: 10.24925/turjaf.v4i12.1134-1138.1069

Anand David AV, Arulmoli R, Parasuraman S. Overviews of Biological Importance of Quercetin: A Bioactive Flavonoid. Pharmacogn Rev. 2016;10(20):84‐89. doi: 10.4103/0973-7847.194044

Serban, M. C., Sahebkar, A., Zanchetti, A., Mikhailidis, D. P., Howard, G., Antal, D., Andrica, F., Ahmed, A., Aronow, W. S., Muntner, P., Lip, G. Y., Graham, I., Wong, N., Rysz, J., Banach, M., & Lipid and Blood Pressure Meta‐analysis Collaboration (LBPMC) Group (2016). Effects of Quercetin on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Journal of the American Heart Association, 5(7), e002713. DOI: 10.1161/JAHA.115.002713

Xu D, Hu MJ, Wang YQ, Cui YL. Antioxidant Activities of Quercetin and Its Complexes for Medicinal Application. Molecules. 2019;24(6):1123. Published 2019 Mar 21. doi: 10.3390/molecules24061123

Alía, M., Mateos, R., Ramos, S., Lecumberri, E., Bravo, L., & Goya, L. (2006). Influence of quercetin and rutin on growth and antioxidant defense system of a human hepatoma cell line (HepG2). European journal of nutrition, 45(1), 19–28. DOI: 10.1007/s00394-005-0558-7

Robaszkiewicz, A., Balcerczyk, A., & Bartosz, G. (2007). Antioxidative and prooxidative effects of quercetin on A549 cells. Cell biology international, 31(10), 1245–1250. DOI: 10.1016/j.cellbi.2007.04.009

Kim, G. N., & Jang, H. D. (2009). Protective mechanism of quercetin and rutin using glutathione metabolism on HO-induced oxidative stress in HepG2 cells. Annals of the New York Academy of Sciences, 1171, 530–537. DOI: 10.1111/j.1749-6632.2009.04690.x

Baghel, Satyendra & Shrivastava, Nikhil & Baghel, PA & Rajput, Sarlesh. (2012). A review of quercetin: Antioxidant and anticancer properties. World J Pharm Pharmaceutical Sci. 1. 146 - 160.

Zinc

Kaltenberg, J., Plum, L. M., Ober-Blöbaum, J. L., Hönscheid, A., Rink, L., & Haase, H. (2010). Zinc signals promote IL-2-dependent proliferation of T cells. European journal of immunology, 40(5), 1496–1503. DOI: 10.1002/eji.200939574

Shankar, A. H., & Prasad, A. S. (1998). Zinc and immune function: the biological basis of altered resistance to infection. The American journal of clinical nutrition, 68(2 Suppl), 447S–463S. DOI: 10.1093/ajcn/68.2.447S

Barnett, J. B., Dao, M. C., Hamer, D. H., Kandel, R., Brandeis, G., Wu, D., Dallal, G. E., Jacques, P. F., Schreiber, R., Kong, E., & Meydani, S. N. (2016). Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. The American journal of clinical nutrition, 103(3), 942–951. DOI: 10.3945/ajcn.115.115188

Barnett JB, Hamer DH, Meydani SN. Low zinc status: a new risk factor for pneumonia in the elderly? Nutrition Reviews. 2010 Jan;68(1):30-37. DOI: 10.1111/j.1753-4887.2009.00253.x 

Yasuda, Hiroshi. (2017). The Situation of Zinc Deficiency: Early Assessment and Intervention Are Essential. Biomedical Research on Trace Elements. 125-140. DOI: 10.11299/brte.27.125

Hemilä H. Zinc lozenges may shorten the duration of colds: a systematic review. Open Respir Med J. 2011;5:51‐58. doi: 10.2174/1874306401105010051

Rerksuppaphol, S., & Rerksuppaphol, L. (2013). A randomized controlled trial of chelated zinc for prevention of the common cold in Thai school children. Paediatrics and international child health, 33(3), 145–150. DOI: 10.1179/2046905513Y.0000000064