Vitamin C: health benefits, supplements, and more

Vitamin C may be the poster child for immune support, but it has many other health benefits that go beyond the common cold. From dietary sources to supplementation options, here’s everything you need to know about this essential nutrient.

Often thought of as the “go-to” nutrient for sickness, vitamin C has become the designated poster child for immunity. And for good reason, as studies continue to show its positive impact on immune health. But is vitamin C good for anything other than fighting off the common cold? From blood pressure regulation to increased iron absorption, here’s everything you need to know about vitamin C, and why you may want to include it in your supplement routine.

What is vitamin C?

Also known as L-ascorbic acid, vitamin C is an antioxidant that is necessary for collagen synthesis. It’s also involved with protein metabolism and may help to prevent or delay the development of cardiovascular disease and certain cancers [1]. Since humans don’t produce vitamin C, it’s necessary to obtain it through certain foods and supplements.  

What's the difference between vitamin C and liposomal vitamin C?

The difference between vitamin C and liposomal vitamin C has to do with absorption rates. 
Regular oral supplement forms of vitamin C can only raise vitamin blood levels to a certain extent, whereas liposomal vitamin C is a form of vitamin C that is generally better absorbed [2,3]. The latter can also raise your blood levels more efficiently since it’s 1.77 times more bioavailable than other vitamin C supplements [3,4]. 

Vitamin C benefits

While vitamin C is well-known for its immune support, it has many other health benefits that go beyond the common cold. Here are some science-backed benefits of this well-known vitamin. 

Manage high blood pressure and reduce the risk of CVD.

Vitamin C may have a positive impact on heart health, as it can act as a diuretic to help lower blood pressure [5]. As such, studies show that vitamin C is inversely associated with both systolic blood pressure and diastolic blood pressure, and that supplementation can promote a significant reduction in blood pressure in those who have hypertension [6,7]. 

Reduces inflammation.

This antioxidant may help reduce inflammation by neutralizing free radicals that cause oxidative damage to cells [8,9]. Studies show that 500 mg of vitamin C (taken twice daily) has also been beneficial in lowering inflammatory markers like CRP, IL-6, and FBG in hypertensive and/or diabetic obese people [10]. 

Prevent iron deficiency.

Research shows that iron and vitamin C are a match made in heaven. When paired together, it could result in a 67% increase in iron absorption [11,12,13].  
Learn more about iron in this article.

Protects memory as we age.

Emerging research shows that vitamin C can have a protective effect against age-related cognitive decline and Alzheimer’s disease [14]. 
woman holding a picture of a brain with brain-healthy foods

Boosts immune health.

Vitamin C is crucial to keep your immune defenses up and running, as it helps stimulate the production of white blood cells (also known as leukocytes) to help ward off viruses and bacteria [15]. 
Since a deficiency may result in impaired immunity and higher susceptibility to infections, supplementation appears to have a positive impact on preventing illness and reducing its severity [16]. 
For instance, studies have shown that supplementing with vitamin C can shorten the amount of time that you are sick by up to 12% and seems to be most effective when taken before or at the onset of symptoms [17]. Research has also found that marathon runners who took a daily vitamin C supplement had a 50% reduced chance of developing a common cold [18]. 
Other studies show that a combination of vitamin C and zinc may prove effective in warding off the common cold [19].  

Improves skin appearance.

Vitamin C has long been hailed as the holy grail of skincare, and for good reason. Research shows that topically applying vitamin C can accelerate the production of collagen and elastin to help prevent premature aging and reduce the appearance of fine lines and wrinkles [20]. 

How much vitamin C per day?

The recommended daily amount (RDA) for adults is as follows [1]: 
  • Men and women 9–13 years old: 45 mg/day
  • Men 14-18 years old: 75 mg/day
  • Women 14-18 years old: 65 mg/day, with this number increasing to 80 mg/day and 115 mg/day for pregnant and lactating women, respectively. 
  • Men over 19 years old: 90 mg/day
  • Women over 19 years old: 75 mg/day, with this number increasing to 85 mg/day and 120 mg/day for pregnant and lactating women, respectively. 
  • People who smoke: an additional 35 mg/day than nonsmokers.

What affects vitamin C status? 

The following demographics tend to be at a higher risk for vitamin C deficiency [21]:
  • Males ages 20–59
  • Black and Mexican Americans
  • Smokers
  • Individuals with increased BMI
  • Those experiencing poverty or food insecurity

Can I take vitamin C while pregnant?

Yes, you can take vitamin C while pregnant. However, be sure to check with your healthcare provider for dosing recommendations to avoid any adverse health effects. 

Best time to take vitamin C

You can take vitamin C supplements any time of day (either with or without food). However, science shows that taking it with food can help decrease the risk of any side effects [22]. 

Foods rich in vitamin C

Some foods rich in vitamin C include oranges, kiwis, lemons, grapefruits, bell peppers, strawberries, tomatoes, broccoli, brussels sprouts, and potatoes.
For reference, an orange has 51 mg of vitamin C, whereas one medium strawberry has 7 mg of vitamin C.
orange slice half filled with white pills

Best vitamin C supplement

You can find a multitude of vitamin C supplements on the market, but not all supplements are created equal. 
Unlike food, supplement regulation is largely in the hands of manufacturers, and FDA approval for supplements is only required when the product contains a new ingredient. As such, the best vitamin C supplement is one that has been third-party tested.
Learn more about Elo’s rigorous third-party testing
If you’re confused about the quality of vitamin C supplements, or how much you should take, there’s no need to worry. At Elo Health, we take the guesswork out of the equation by using science to recommend the right nutrition and supplements for you.
Additionally, you have access to our Registered Dietitians and Elo Health coaches to help guide you on your nutrition and health journey.
Your body is unique, and so are your nutrition needs. Here’s how Elo can help you feel your best.

Can you overdose on vitamin C?

Yes, you can have too much vitamin C. While many people tolerate it well, some side effects of vitamin C include diarrhea, nausea, abdominal cramps, and other gastrointestinal issues [1]. These side effects are more likely to occur with doses of 2,000 mg/day of vitamin C or greater. 

Precautions

While many people can tolerate vitamin C, there are a few contraindications that you should be aware of. 
  • Drug-nutrient interactions. High doses of aspirin (about 900 mg) may increase the loss of vitamin C in the urine and reduce its absorption [23,24]. As such, long-term aspirin use may affect your body’s ability to maintain adequate vitamin C levels. 
  • CVD risk. Research suggests that taking vitamin C supplements can increase the risk of cardiovascular disease [25]. However, more research is needed on this topic.
  • Iron overload. You should be cautious about taking vitamin C supplements if you have a condition that increases the risk of iron accumulation in the body (such as hemochromatosis). In this case, excess vitamin C may lead to iron overload, which can cause serious damage to your heart, liver, pancreas, thyroid, and central nervous system [26]. 
Before adding a new supplement to your routine, it’s recommended to talk with your healthcare provider to make sure it’s the right fit for you.

Summary

Vitamin C may be the poster child for immune support, but studies show that it can also positively impact blood pressure, inflammation, iron absorption, and cognitive function. You can find vitamin C in citrus fruits, certain vegetables, and supplements. 
If you smoke, are a male between 20 and 59 years old, have an increased BMI, or are a Black or Mexican American, you may want to consider additional supplementation since you are at a higher risk of developing a deficiency.
 Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.

Key takeaways

  • Vitamin C is an essential nutrient that has been shown to positively impact immunity, blood pressure, inflammation, iron absorption, and cognitive function.
  • People who are at a higher risk for vitamin C deficiency include smokers, men between 20 and 59 years old, those with an increased BMI, and Black or Mexican Americans.
  • Some side effects of vitamin C include diarrhea, nausea, abdominal cramps, and other gastrointestinal issues [1]. 
  • At Elo Health, we help you meet your nutrition needs by using science to recommend the right supplements for you.

References

  1. U.S. Department of Health and Human Services. (n.d.). Office of dietary supplements - vitamin C. NIH Office of Dietary Supplements. Retrieved October 7, 2022, from https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/ 
  2. Prantl, L., Eigenberger, A., Gehmert, S., Haerteis, S., Aung, T., Rachel, R., Jung, E. M., & Felthaus, O. (2020). Enhanced Resorption of Liposomal Packed Vitamin C Monitored by Ultrasound. Journal of clinical medicine, 9(6), 1616. https://doi.org/10.3390/jcm9061616 
  3. Jillian Kubala, M. S. (2022, March 29). Liposomal vitamin C benefits and best supplements. Greatist. Retrieved October 7, 2022, from https://greatist.com/health/liposomal-vitamin-c 
  4. Gopi, S., & Balakrishnan, P. (2020). Evaluation and clinical comparison studies on liposomal and non-liposomal ascorbic acid (vitamin C) and their enhanced bioavailability. Journal of Liposome Research, 31(4), 356–364. https://doi.org/10.1080/08982104.2020.1820521 
  5. Big doses of vitamin C may lower blood pressure. Johns Hopkins Medicine. Retrieved October 7, 2022, from https://www.hopkinsmedicine.org/news/media/releases/big_doses_of_vitamin_c_may_lower_blood_pressure 
  6. Ran, L., Zhao, W., Tan, X., Wang, H., Mizuno, K., Takagi, K., Zhao, Y., & Bu, H. (2020). Association between serum vitamin C and the blood pressure: A systematic review and meta-analysis of observational studies. Cardiovascular Therapeutics, 2020, 1–11. https://doi.org/10.1155/2020/4940673 
  7. Guan, Y., Dai, P., & Wang, H. (2020). Effects of vitamin C supplementation on essential hypertension. Medicine, 99(8). https://doi.org/10.1097/md.0000000000019274 
  8. Żychowska, M., Grzybkowska, A., Zasada, M., Piotrowska, A., Dworakowska, D., Czerwińska-Ledwig, O., Pilch, W., & Antosiewicz, J. (2021). Effect of six weeks 1000 mg/day vitamin C supplementation and healthy training in elderly women on genes expression associated with the immune response - A randomized controlled trial. Journal of the International Society of Sports Nutrition, 18(1). https://doi.org/10.1186/s12970-021-00416-6 
  9. Carr, A., & Maggini, S. (2017). Vitamin C and immune function. Nutrients, 9(11), 1211. https://doi.org/10.3390/nu9111211 
  10. Ellulu, M. S., Rahmat, A., Patimah, I., Khaza'ai, H., & Abed, Y. (2015). Effect of vitamin C on inflammation and metabolic markers in hypertensive and/or diabetic obese adults: a randomized controlled trial. Drug design, development and therapy, 9, 3405–3412. https://doi.org/10.2147/DDDT.S83144 
  11. Hurrell, R., & Egli, I. (2010). Iron bioavailability and dietary reference values. The American journal of clinical nutrition, 91(5), 1461S–1467S. https://doi.org/10.3945/ajcn.2010.28674F 
  12. Vitamin C and Iron: A perfect match. Food Insight. (2018, October 10). Retrieved October 7, 2022, from https://foodinsight.org/vitamin-c-and-iron-a-perfect-match/ 
  13. Hallberg, L., & Hulthén, L. (2000). Prediction of dietary iron absorption: an algorithm for calculating absorption and bioavailability of dietary iron. The American journal of clinical nutrition, 71(5), 1147–1160. https://doi.org/10.1093/ajcn/71.5.1147 
  14. Harrison F. E. (2012). A critical review of vitamin C for the prevention of age-related cognitive decline and Alzheimer's disease. Journal of Alzheimer's disease : JAD, 29(4), 711–726. https://doi.org/10.3233/JAD-2012-111853 
  15. Vitamin C. Linus Pauling Institute. (2022, August 23). Retrieved October 7, 2022, from https://lpi.oregonstate.edu/mic/vitamins/vitamin-C 
  16. Carr, A. C., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. https://doi.org/10.3390/nu9111211 
  17. Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews, 2013(5). https://doi.org/10.1002/14651858.cd000980.pub4 
  18. Bucher, A., & White, N. (2016). Vitamin C in the Prevention and Treatment of the Common Cold. American journal of lifestyle medicine, 10(3), 181–183. https://doi.org/10.1177/1559827616629092 
  19. Maggini, S., Beveridge, S., & Suter, M. (2012). A combination of high-dose vitamin C plus zinc for the common cold. Journal of International Medical Research, 40(1), 28–42. https://doi.org/10.1177/147323001204000104 
  20. Pullar, J. M., Carr, A. C., & Vissers, M. (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8), 866. https://doi.org/10.3390/nu9080866 
  21. Crook, J., Horgas, A., Yoon, S.-J., Grundmann, O., & Johnson-Mallard, V. (2021). Insufficient vitamin C levels among adults in the United States: Results from the Nhanes Surveys, 2003–2006. Nutrients, 13(11), 3910. https://doi.org/10.3390/nu13113910 
  22. Lee, J. K., Jung, S. H., Lee, S. E., Han, J. H., Jo, E., Park, H. S., Heo, K. S., Kim, D., Park, J. S., & Myung, C. S. (2018). Alleviation of ascorbic acid-induced gastric high acidity by calcium ascorbate in vitro and in vivo. The Korean journal of physiology & pharmacology : official journal of the Korean Physiological Society and the Korean Society of Pharmacology, 22(1), 35–42. https://doi.org/10.4196/kjpp.2018.22.1.35 
  23. Basu T. K. (1982). Vitamin C-aspirin interactions. International journal for vitamin and nutrition research. Supplement = Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Supplement, 23, 83–90. 
  24. Drug-nutrient interactions. Linus Pauling Institute. (2022, July 6). Retrieved October 7, 2022, from https://lpi.oregonstate.edu/mic/drug-nutrient-interactions 
  25. Moser, M. A., & Chun, O. K. (2016). Vitamin C and Heart Health: A Review Based on Findings from Epidemiologic Studies. International journal of molecular sciences, 17(8), 1328. https://doi.org/10.3390/ijms17081328 
  26. Gerster. (1999). High-dose vitamin C: A risk for persons with high iron stores? International Journal for Vitamin and Nutrition Research, 69(2), 67–82. https://doi.org/10.1024/0300-9831.69.2.67