table of contents
If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
“Liquid gold” might already be claimed as the product tagline for Velveeta, but the nickname really should be awarded to your morning glass of orange juice.
The staple of classic American breakfasts has long been associated with vitamin C, a water-soluble vitamin that’s also known as ascorbic acid and ascorbate. It’s also an essential nutrient, which means it cannot be produced by the body.
Centuries ago, frequent seafarers discovered that foods containing this vitamin helped prevent scurvy, a disease caused by a lack of C. But there’s more to this essential nutrient than simply avoiding disease.
Vitamin C is involved in critical processes in your body like development and tissue repair in addition to strengthening your immune system. Here are some more reasons why this vitamin should earn a treasured spot in your healthy lifestyle.
Benefits of vitamin C
You never hear about modern cases of scurvy, but that doesn’t mean deficiency doesn’t happen. It might not be as common as it was during the time of those famous marauders, but about 7% of adults in the United States still suffered from a lack of this essential nutrient between 2003–2004 (Schleicher, 2009).
There are several groups of people that are at increased risk of developing the deficiency, like those who suffer from alcoholism or anorexia. That also includes people who are low income, smoke, are on dialysis, or have a severe mental illness. Even so, it’s possible for everyone to get enough vitamin C intake to reap the health benefits.
It should be noted, though, that everyone is different. There’s no doubt that vitamin C is essential and healthy, but not everyone will experience the same health benefits in the same way. And you might have heard about some purported benefits, like protecting against eye diseases such as age-related macular degeneration, but there isn’t enough research to back up those claims.
1. Supports the immune system
While there’s been some debate about whether you should reach for vitamin C when you’re already sick, it does play a vital role in preventing illness. That’s because this essential nutrient is all about playing defense.
Though vitamin C helps your immune system in multiple ways, they’re all about the prevention of illness, not the treatment of it. Ascorbic acid not only helps prompt your body to make more white blood cells but also helps them work more effectively (Carr, 2017).
These white blood cells, including cells called lymphocytes and phagocytes, protect the body from the threat of infection. But that’s not even all when it comes to vitamin C and immunity.
The water-soluble vitamin is also essential for your body’s biggest organ: your skin. Vitamin C helps maintain and protect the skin barrier, so sources of infection can’t penetrate. It also acts as an antioxidant in the skin, helping it repair.
Another essential benefit to vitamin C is its ability to boost collagen production in your skin, which can assist in wound healing and protect against age-related wrinkles and sagging (Pullar, 2017).
Though vitamin C certainly helps your body strengthen its defenses, we don’t know for sure that it can prevent the common cold. While research does show that supplementing with vitamin C can shorten the duration of your cold, it hasn’t yet shown that these supplements can prevent you from catching one in the first place (Hemilä, 2013).
2. Promotes wound healing
Vitamin C plays a vital role in wound healing. Numerous studies have shown that vitamin C deficiency is associated with delayed healing. In fact, one of the defining features of scurvy, the disease of vitamin C deficiency, is poor wound healing. Although research is limited, vitamin C supplementation may also help speed healing up (Bikker, 2016).
Small studies have been done testing the effect of ascorbic acid on pressure ulcers or sores, more commonly known as bed sores. These sores are common in people who have lost their mobility, such as people in hospitals and nursing homes.
The studies found that high doses of vitamin C significantly improved the rate of healing in patients. One showed that after one month of supplementation, the pressure sore area had reduced by 84% in the vitamin C group, and only 42.7% in the placebo group (Desneves, 2005).
3. Help fight respiratory infections
You probably never thought about vitamin C and your lungs working together, but they do. Ascorbic acid is essential for metabolic functioning in your lungs, and people who suffer from pulmonary tuberculosis (PTB) and pneumonia tend to have low blood levels of the crucial vitamin.
And a meta-analysis of placebo-controlled trials, in which some people got vitamin C and others got pills that appeared the same but had no vitamins, found a significantly lower rate of infection with pneumonia in the group that got the vitamin. The analysis also found evidence that C can shorten the duration of pneumonia, and that high doses may be especially effective (Hemilä, 2013).
However, there was one study they analyzed that showed that vitamin C didn’t effectively prevent pneumonia in burn victims. More research needs to be done to identify the benefits of vitamin C in pneumonia conclusively.
4. May protect against certain cancers
People get really excited about potential cancer prevention that can be done at home and for good reason.
Researchers who support the idea that vitamin C can cause a lower risk of cancer say this is because of how the vitamin can act as an antioxidant, preventing cancer-causing cellular damage caused by free radicals.
But the research on vitamin C and cancer is still unclear. Though some studies indicate that vitamin C intake and lower cancer risk are linked, a meta-analysis of seven trials that included a total of 62,619 participants found no statistically significant link (Lee, 2015).
The idea seems mostly based on old research that found a therapeutic effect in advanced cancer patients treated with high-dose C compared to those untreated. Research that came out shortly after, however, showed no beneficial effect of ascorbic acid for cancer patients.
5. Reduce risk of chronic diseases
As you’ve probably noticed, acting as an antioxidant in your body is one of vitamin C’s main talents. Cellular damage that leads to cancer and chronic diseases is caused by molecules like free radicals.
Allowed to accumulate in the body, these free radicals cause a condition called oxidative stress — just a more complicated way of saying your antioxidants and free radicals are not balanced, so the damage being done is not counterbalanced or repaired.
Even things that are good for us (like exercise) cause oxidative stress, which is linked to the development of many chronic diseases, but antioxidants, such as vitamin C, can protect your body from that damage.
It’s not just oxidative stress that vitamin C can counteract. Inflammation is also associated with many chronic diseases. Ascorbic acid has been shown to be effective at reducing inflammatory markers in humans, as well as combating inflammation caused by exercise (Ellulu, 2015; Popovic, 2015).
These health benefits are only possible if your intake of vitamin C is adequate. Luckily, for those who struggle to get enough vitamin C, supplements have been proven to raise blood levels of this crucial nutrient significantly.
6. Supports heart health
Heart disease, or cardiovascular disease, is actually a cluster of conditions that involve disease or structural issues with the blood vessels or heart tissue, as well as clots.
Many factors that you’ll recognize — such as high “bad” LDL cholesterol, low “good” HDL cholesterol, and high triglycerides — increase your risk of developing the disease.
Several studies have found that vitamin C can help protect against these risk factors, as well as heart disease. It’s worth noting that in one of the studies, researchers found the protective effects came from vitamin C-rich foods and not supplements.
However, they aren’t sure if there were other factors that could explain the results, like the group with a higher dietary intake, simply having healthier lifestyles overall.
Another major risk factor for heart disease is high blood pressure or hypertension. It’s not one to ignore as 32% of American adults already suffer from the condition, and one in three have prehypertension, higher than normal blood pressure that doesn’t quite meet the criteria for high blood pressure. Vitamin C supplementation was able to reduce both systolic blood pressure (SBP) and diastolic blood pressure (DBP) short-term in participants in one study (Juraschek, 2012).
It’s promising, but the researchers do note that more work needs to be done to confirm the long-term efficacy of this treatment. And it’s worth noting that you still need to work with a healthcare provider and take prescription medication as directed if you suffer from high blood pressure.
7. Improves iron absorption
Most women have been warned about the risk of anemia or iron deficiency by their healthcare providers, but men may not be as familiar. Anemia can also be caused by a number of other factors, including a lack of folate, vitamin B12, or vitamin E.
Iron is essential for red blood cell production and transporting oxygen throughout the body, which is why anemia is associated with low energy levels. Unfortunately, our bodies can’t always use the iron we get through dietary intake efficiently, and that’s where vitamin C comes in.
Ascorbic acid can help your body get enough iron by converting it into a form that’s easier to absorb. That’s especially important for vegetarians and vegans since iron from meat is better absorbed by our bodies than iron from plants.
In fact, one study found that vitamin C helped boost absorption of iron two- or three-fold, and is most effective when the dose is divided and taken with each meal. This nutrient may also be helpful if you already have anemia. Supplements may also improve levels of vitamin C in children with mild iron deficiencies.
But vitamin C supplements are more important when you’re eating whole foods. Fortified foods, which have vitamins and other nutrients added back in, are often made with extra iron as well as vitamin A and beta carotene, both of which help our bodies absorb the micronutrient. Your orange juice, for example, may be more helpful at lunchtime compared to breakfast if you eat a bowl of fortified breakfast cereal.
8. May protect you from gout
Like scurvy, gout is a condition we file neatly into the past even though it’s still a danger in the present. This form of inflammatory arthritis causes severe pain, tenderness, and redness at joints and develops in some people who have high levels of uric acid, a waste product, in their systems.
Excess uric acid forms needle-like crystals at the joints, which results in sudden and intense episodes of pain — especially in big toes. While there’s no study that shows vitamin C can reduce gout symptoms, a meta-analysis did find that supplementing for 30 days significantly reduced participants’ levels of uric acid (Juraschek, 2011).
And there are even more studies that suggest there’s a link between vitamin C and gout, even if we don’t know exactly what that is yet. But the work does support the idea that supplements might be a good method for helping to prevent the condition.
Another study of 1,387 men found that those with higher vitamin C intake had lower blood levels of uric acid. And higher amounts of vitamin C, achieved through supplements, were associated with a 44% lower chance of developing gout in one clinical trial (Gao, 2008; Choi, 2009).
9. May protect cognitive function
Remember oxidative stress? It doesn’t just take a toll on your heart. Researchers believe that oxidative stress and inflammation both increase your risk of dementia, the hallmark signs of which are poor cognition and memory (Raz, 2016).
You already know that vitamin C can act as an antioxidant to protect us from oxidative stress, but researchers have also found a correlation between low vitamin C levels and dementia in older adults (von Arnim, 2012).
Further studies have clarified this link. Low vitamin C levels, even those that don’t qualify as a deficiency, have been linked to poor cognitive skills. Higher intakes of vitamin C, vitamin E, and beta carotene are associated with lessened or delayed cognitive decline and lowered risk of Alzheimer’s disease.
Researchers believe vitamin C may have a protective effect on cognitive skills like thinking and memory, though more work needs to be done to clarify the connection and account for other factors.
Sources of vitamin C
OK, you’re sold. You know you need to get enough vitamin C. So how much do you need?
For adults 19 years and older, that magic number or Recommended Dietary Allowance (RDA) is 75 mg for women and 90 mg for men, though pregnant women need 85 mg daily (NIH, 2019).
Since we cannot produce our own ascorbic acid, you’ll need to meet these daily requirements through dietary intake, supplements, or a combination of the two. Luckily, there are plenty of foods that boast a large amount of vitamin C per serving, and not just citrus fruits like oranges and grapefruits.
And there are simple ways to hit your daily needs or get very close, within one meal. Add 100 g kiwifruit to your plate (just under two fruits), for example, and you’ll get 93.2 mg of vitamin C (USDA, 2019).
The same amount of cantaloupe, green pepper, or Brussels sprouts pack 35.8 mg, 80.4 mg, and 84.7 mg respectively. Choose red pepper instead of green, and you’ll get over 100% of your daily value of the nutrient, a whopping 127.7 mg of vitamin C.
But dietary supplements are also an option and may be necessary for people with absorption issues. You should talk to a medical professional about your best options if you have risk factors for low vitamin C levels.
Taking too much does come with side effects and may interfere with the absorption of other key nutrients. If you get enough vitamin C through your diet, you may not even need this nutrient in your multivitamin. A healthcare professional can help guide you based on your unique needs.
- Bikker, A., Wielders, J., van Loo, R., & Loubert, M. (2016). Ascorbic acid deficiency impairs wound healing in surgical patients: Four case reports. International Journal of Surgery Open, 2, 15–18. doi: 10.1016/j.ijso.2016.02.009, https://www.sciencedirect.com/science/article/pii/S2405857215300346
- Carr, A., & Maggini, S. (2017). Vitamin C and Immune Function. Nutrients, 9(11), 1211. doi: 10.3390/nu9111211, https://www.ncbi.nlm.nih.gov/pubmed/29099763
- Choi, H. K., Gao, X., & Curhan, G. (2009). Vitamin C Intake and the Risk of Gout in Men – A Prospective Study. Archives of Internal Medicine, 169(5), 502–507. doi: 10.1001/archinternmed.2008.606, https://www.ncbi.nlm.nih.gov/pubmed/19273781
- Desneves, K., Todorovic, B., Cassar, A., & Crowe, T. (2005). Treatment with supplementary arginine, vitamin C and zinc in patients with pressure ulcers: A randomised controlled trial. Clinical Nutrition, 24(6), 979–987. doi: 10.1016/j.clnu.2005.06.011, https://www.researchgate.net/publication/7470122_Treatment_with_supplementary_arginine_vitamin_C_and_zinc_in_patients_with_pressure_ulcers_A_randomised_controlled_trial
- Ellulu, M. S., Rahmat, A., Ismail, P., Khazaai, 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. doi: 10.2147/dddt.s83144, https://www.ncbi.nlm.nih.gov/pubmed/26170625
- Gao, X., Curhan, G., Forman, J. P., Ascherio, A., & Choi, H. K. (2008). Vitamin C Intake and Serum Uric Acid Concentration in Men. The Journal of Rheumatology, 35(9), 1853–1858. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2853937/
- Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. doi: 10.1002/14651858.cd000980.pub4, https://www.ncbi.nlm.nih.gov/pubmed/23440782
- Juraschek, S. P., Guallar, E., Appel, L. J., & Miller, E. R. (2012). Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition, 95(5), 1079–1088. doi: 10.3945/ajcn.111.027995, https://www.ncbi.nlm.nih.gov/pubmed/22492364
- Lee, B., Oh, S.-W., & Myung, S.-K. (2015). Efficacy of Vitamin C Supplements in Prevention of Cancer: A Meta-Analysis of Randomized Controlled Trials. Korean Journal of Family Medicine, 36(6), 278–285. doi: 10.4082/kjfm.2015.36.6.278, https://www.ncbi.nlm.nih.gov/pubmed/26634093
- Mao, X., & Yao, G. (1992). Effect of vitamin C supplementations on iron deficiency anemia in Chinese children. Biomedical and Environmental Sciences, 5(2), 125–129. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1642785
- National Institutes of Health: Office of Dietary Supplements. (2019, July 9). Vitamin C: Intakes and Status. Retrieved from https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#h4
- Paleologos, M., Cumming, R. G., & Lazarus, R. (1998). Cohort Study of Vitamin C Intake and Cognitive Impairment. American Journal of Epidemiology, 148(1), 45–50. doi: 10.1093/oxfordjournals.aje.a009559, https://www.ncbi.nlm.nih.gov/pubmed/9663403
- Popovic, L. M., Mitic, N. R., Miric, D., Bisevac, B., Miric, M., & Popovic, B. (2015). Influence of Vitamin C Supplementation on Oxidative Stress and Neutrophil Inflammatory Response in Acute and Regular Exercise. Oxidative Medicine and Cellular Longevity, 2015. doi: 10.1155/2015/295497, https://www.ncbi.nlm.nih.gov/pubmed/25802681
- Pullar, J. M., Carr, A. C., & Vissers, M. C. M. (2017). The Roles of Vitamin C in Skin Health. Nutrients, 9(8), 866. doi: 10.3390/nu9080866, https://www.ncbi.nlm.nih.gov/pubmed/28805671
- Raz, L., Knoefel, J., & Bhaskar, K. (2016). The neuropathology and cerebrovascular mechanisms of dementia. Journal of Cerebral Blood Flow & Metabolism, 36(1), 172–186. doi: 10.1038/jcbfm.2015.164, https://www.ncbi.nlm.nih.gov/pubmed/26174330
- Schleicher, R. L., Carroll, M. D., Ford, E. S., & Lacher, D. A. (2009). Serum vitamin C and the prevalence of vitamin C deficiency in the United States: 2003–2004 National Health and Nutrition Examination Survey (NHANES). The American Journal of Clinical Nutrition, 90(5), 1252–1263. doi: 10.3945/ajcn.2008.27016, https://www.ncbi.nlm.nih.gov/pubmed/19675106
- U.S. Department of Agriculture (USDA). (2019, April 1). FoodData Central. Retrieved from https://fdc.nal.usda.gov/index.html
- von Arnim, C. A. F., Herbolsheimer, F., Nikolaus, T., Peter, R., Biesalski, H. K., Ludolph, A. C., … Nagel, G. (2012). Dietary Antioxidants and Dementia in a Population-Based Case-Control Study among Older People in South Germany. Journal of Alzheimer’s Disease, 31(4), 717–724. doi: 10.3233/jad-2012-120634, https://europepmc.org/article/med/22710913
- Wengreen, H. J., Munger, R., Corcoran, C., Zandi, P., Hayden, K. M., Fotuhi, M., … Welsh-Bohmer, K. A. (2007). Antioxidant intake and cognitive function of elderly men and women: the Cache County Study. The Journal of Nutrition, Health & Aging, 11(3), 230–237. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/17508099/