Vitamin C is a water-soluble vitamin that is quickly metabolized in the body. It is vital for so many crucial functions in the body, and unlike plants and the majority of animals, humans cannot synthesize, produce, or even store it. That is why it is considered an essential dietary component that we need to consume daily.
Vitamin C, or ascorbic acid, L-ascorbic acid, or L-ascorbate as it is referred to in medical circles, is essential for multiple functions in the body. As an antioxidant, it protects against certain chronic diseases, and more generally, as a nutrient, it acts as a catalyst to make other systems in the body work better and more efficiently.
You would think that a nutrient of this caliber, with such critical roles in the human body, would have been identified eons ago. But the truth is, vitamin C wasn’t isolated as a vital nutrient until the 1930s by Hungarian researcher Albert Szent-Gyorgi.
Mr. Szent-Gyrogyi’s work on the identification of vitamin C found him the recipient of a Nobel Prize in Physiology/Medicine. This came nearly 150 years after the British navy required lime juice to be consumed by British sailors after hundreds of years of deaths due to what researchers today believe was scurvy.
Scurvy is a severe vitamin C deficiency that can occur in as little as 30 days without consumption of this essential antioxidant. And scurvy can be fatal if left untreated. Fortunately, there are a wide variety of fruits and vegetables that are excellent sources of vitamin C. In broad strokes, vitamin C-rich foods include the kiwi fruit, bell peppers, tropical fruits like papaya and pineapple, and of course, citrus fruits. All of these foods are known cancer fighters.
In addition to western medicine, vitamin C plays an essential role in traditional Ayurvedic medicine. In fact, one of the most popular Ayurvedic supplements is Amla, a natural vitamin C that is made from Amalaki, an Indian Gooseberry. There is significant debate as to the actual vitamin C content of Amalaki, but in India, it is believed to contain 10 times that of a medium-sized orange. Ancient Ayurvedic texts promote the use of Amla to prevent aging and promote longevity.
Closer to home, the Cherokee Nation makes vitamin C-rich teas made from common sumac that is used in their healing practices to soothe sore throats and as a remedy for diarrhea and even poison ivy. Cherokee healers also use the vitamin C-rich fruit from the wild rose or Jisdu unigisdi as a preventative and cure for the common cold.
Essential Roles Vitamin C Plays in the Body
Vitamin C is an antioxidant that blocks some of the damage caused by free radicals. Free radicals occur when the body breaks down food or when you are exposed to certain toxins such as tobacco smoke or radiation. Killing these free radicals is crucial for wellness, as the buildup of free radicals is largely responsible for the aging process. And research indicates that free radicals may play a role in the development of arthritis, cancer, heart disease, and other chronic conditions.
In addition to protecting against free radical damage, adequate levels of vitamin C are required for the synthesis of collagen. Collagen is the key building block that supports the creation of new tissue. It is an essential protein for healthy skin and wound healing. Collagen is also found in connective tissues, including blood vessels, bones, cartilage, gums, and muscles. Without enough vitamin C to facilitate the development of collagen, all of these tissues can be harmed.
Vitamin C also increases the absorption of iron found in fruits, nuts, and vegetables. Iron is essential for the prevention of anemia. In a review of multiple clinical trials published in The American Journal of Clinical Nutrition, researchers found that 100 milligrams of vitamin C can increase iron absorption rates substantially. In fact, taking vitamin C with a meal increased iron absorption by up to 67% in some of the trials. The researchers from the Department of Clinical Nutrition at the University of Goteborg in Sweden also found that coffee, red wine, and tea can inhibit the absorption of iron.
Vitamin C plays a critical role in central nervous system health. Ascorbic acid is concentrated in the brain and neuroendocrine tissues, including the adrenal glands. According to researchers, vitamin C protects the brain against oxidative stress and may help prevent several types of neurodegenerative diseases. Researchers from the Department of Medicine at Vanderbilt University School of Medicine encourage further investigation into the role ascorbic acid plays in brain function.
12 Outstanding Vitamin C Benefits
Vitamin C plays so many critical roles in our body, and research shows that vitamin C has promise for a wide range of chronic health problems. Here are 12 outstanding health benefits of vitamin C.
1. Boosts the Immune System
In the United States, taking a vitamin C supplement is standard practice at the first sign of a cold. And, as it turns out, taking vitamin C when you get sick is more than just an old wives’ tale. In fact, research backs this long-held practice by confirming that increasing vitamin C intake alongside zinc reduces symptoms and shortens the duration of the common cold and other respiratory tract infections.
In a review of randomized controlled trials published in the Annals of Nutrition and Metabolism, researchers from Switzerland note that a combination of vitamin C and zinc can improve the outcome of pneumonia, malaria, and diarrhea infections, especially in children. The review focused on clinical trials with vitamin C doses of up to 1 gram and zinc doses up to 30 milligrams.
Many types of cancer are linked to free radicals and oxidative stress. However, a diet rich in fruits and vegetables may help protect against certain types, including breast cancer, colon cancer, and lung cancer. And high doses of vitamin C may kill cancer.
In a clinical trial published in Biochimica et Biophysica Acta, researchers identified that high-dose ascorbic acid appears to be detrimental to certain tumor cells. As with many of the studies on vitamin C, the researchers urge further study to explore the full potential of intravenous high-dose vitamin C as an effective treatment for specific types of cancer.
3. Fights Free-radical Damage
Dietary vitamin C is an excellent antioxidant that helps to fight free-radical damage. In fact, consuming adequate vitamin C can help prevent the buildup of free radicals and protect your body from developing certain chronic diseases according to a study authored by researchers from the Digestive Diseases Branch at the National Institutes of Health. The report specifically mentions that vitamin C lowers the risk of cardiovascular disease, stroke, and cancer and is linked to improved longevity.
4. Cardiovascular Health Protection
Getting enough vitamin C, particularly from a variety of food sources, may help lower the risk of stroke and coronary heart disease. In a landmark study on vitamin C and heart health, Researchers from the University of Southampton in the U.K. found that in elderly people, vitamin C concentration is strongly related to a lower risk of death from stroke.
The findings of this study published in The BMJ show that mortality from stroke was highest in study participants with the lowest vitamin C levels. This was a long-term, 20-year follow-up study that ran from 1973 to 1993.
Additionally, high blood pressure is a risk factor for developing coronary heart disease and stroke. In a small-scale study, participants were randomly given 500, 1000, or 2000 milligrams of vitamin C daily for 8 months. Blood pressure scores improved equally across all doses.
5. Healthy Skin
Fifteen or 20 years ago the market was flooded with skincare products made with vitamin C. As it turns out, topical vitamin C is effective for anti-aging, fighting pigmentation, and dark spots, and reducing wrinkles according to a study published recently in The Journal of Clinical and Aesthetic Dermatology.
Getting enough vitamin C from the foods you eat or through dietary supplements can help you get the healthy, glowing skin you desire. Vitamin C, as mentioned above, is involved in the chemical reaction that allows collagen to work its magic in skin repair and wound healing.
6. Brain Health
Ascorbic acid fights oxidative stress, particularly in the central nervous system. Research has shown that vitamin C is a natural neuroprotective agent, and preliminary studies are showing very promising results for the treatment of ALS, Huntington’s disease, Alzheimer’s disease, and Parkinson’s disease. In a review of multiple studies published in the International Journal of Molecular Sciences, researchers mention the biggest challenge is that ascorbic acid is so rapidly oxidized it makes it difficult to keep it viable long enough for treatment.
7. Gastrointestinal Health
In the manuscript, “Vitamin C, Gastritis, and Gastric Disease: a historical review and update” researchers dive into vitamin C and its benefits for gut health. In fact, they found that diets rich in vitamin C are associated with reduced risk of gastric cancer. They note that it is possible that vitamin C successfully attacks free radicals and fights the Helicobacter pylori infection. They go on to mention that in vitro studies show that ascorbic acid produced up to a 90% inhibition of multiple H. pylori strains.
Researchers mention that pharmacological doses (intravenous delivery) of ascorbic acid, under a doctor’s supervision, may improve the effectiveness of H. pylori eradication therapy. Research is still preliminarily, however, this study indicates that daily intake of vitamin C foods may protect your gut.
Getting rid of H. pylori can be difficult. New research published in the journal Frontiers in Physiology states that H. pylori is a known cause of gastritis, peptic ulcers, and stomach cancer and that multiple clinical reports have linked this bacteria to vitamin C deficiencies.
8. Acute and Chronic Pain Management
Researchers from New Zealand have recently identified that vitamin C exhibits pain-relieving properties. In a groundbreaking study published in the Journal of Translational Medicine, researchers note that the effect of vitamin C on cancer-related pain is quite astonishing. The study lists specific cancers and stages and the amount of vitamin C given to patients. In the advanced stages of cancer, patients in palliative care centers need less opioid pain medication when vitamin C was also provided.
Researchers note that vitamin C is a cost-effective, safe, and effective therapy for certain types of pain. The researchers urge further studies into the best dosing, administration, and specific patient groups to learn more about the potential benefits of vitamin C in chronic pain management.
9. Healthy Weight
Vitamin C deficiency has been linked in multiple trials to obesity and high percentages of body fat and waist circumference. Women with higher vitamin C levels have higher levels of the fat-suppressing hormone, adiponectin. And potentially the most exciting vitamin C benefit is that with adequate vitamin C levels, the human body oxidizes 30% more fat during moderate exercise than when individuals have a vitamin C deficiency.
10. Migraine Protection
In a study published in BioMed Research International, researchers found that certain vitamins, including folic acid, vitamin B6, vitamin B12, and vitamin C, can help protect against migraines. Each of the vitamins mentioned play a different role, and vitamin C’s is linked to its “scavenger” abilities to target inflammation. Researchers note that further randomized controlled trials are necessary to determine the true potential of vitamin C supplementation for targeting inflammation in patients with chronic migraines.
11. Muscle Protection
Strenuous and repetitive exercise can cause free radical production leading to an inflammatory response that damages muscles. In a recent study published in Open Access Macedonian Journal of Medical Sciences, researchers have identified that a vitamin C supplement of 500 milligrams a day for 90 days can stop exercise-induced muscle damage caused by oxidative stress. This placebo-driven study focused on male adolescents who exercised 2 to 3 times per week. During the 3-month study, kidney function, C-reactive protein levels, and other vital measurements were monitored closely.
12. Brightens Eyes
Vitamin C has also been shown to help defend against eye diseases, including cataracts and age-related macular degeneration when taken alongside other vital nutrients and antioxidant supplements. It plays an important role in ensuring the health of gums, teeth, cartilage, capillaries, and blood vessels, including those in the eyes.
Best Vitamin C Foods
As several of the studies cited above mention, getting your vitamin C from the foods you eat is best. While there are some herbs, prepared foods, and concentrated juices with higher levels of vitamin C, we chose to focus on the best natural sources you can find in virtually any grocery store or farmers market. To get the best balance of nutrients, eat a variety of fresh fruits and vegetables to meet the daily requirements for vitamin C.
- Guava: 1 cup of guava contains 377 milligrams of vitamin C or 628% of the DV. Guava is also a good source of dietary fiber, vitamin A, folate, potassium, copper, and manganese.
- Yellow and red peppers: 1 large bell pepper contains 341 milligrams of vitamin C or 569% of the DV. These peppers are also a good source of vitamin A, vitamin B6, folate, potassium, and manganese.
- Kiwi: 1 cup of kiwi contains 164 milligrams of vitamin C, providing 273% of the DV. Kiwi is also an excellent source of vitamin K.
- Blackcurrants: 1/2 cup of blackcurrants contains 101 milligrams of vitamin C, representing 167% of the DV.
- Orange: 1 large orange contains 98 milligrams, or 163% DV of vitamin C. Boost your dietary intake of vitamin C even more by enjoying your orange’s peel—just 1 tablespoon contains 8.2 milligrams of vitamin C. Oranges are one of the best anti-cancer foods you can consume.
- Strawberries: 1 cup of strawberries contains 89 milligrams of vitamin C or 149% of the DV. Strawberries are also an excellent source of dietary fiber and manganese.
- Kale: 1 cup of kale provides 87.1 milligrams of vitamin C representing 145% of the recommended DV. Kale is also packed with vitamin A, vitamin E, magnesium, manganese, and calcium.
- Papaya: 1 cup of cubed papaya contains 86.5 milligrams of vitamin C or 144% of the recommended daily value. Papaya is also a great source of vitamin A, folate, and potassium.
- Pineapple: 1 cup of pineapple chunks contains 78.9 milligrams of vitamin C or 131% of the DV. Pineapples also contain the enzyme bromelain that helps to improve digestion by breaking down proteins.
- Broccoli: 1 cup of broccoli florets contains 66.2 milligrams of vitamin C. Broccoli is also an outstanding source of vitamin A, providing 2130 IU, or 43% of the DV. Throw in some Brussels sprouts for a dynamic cruciferous duo with high levels of vitamin C.
Symptoms of Vitamin C Deficiency
The symptoms of vitamin C deficiency can vary quite significantly from person to person. If you experience one or more of the common indicators of a vitamin C deficiency listed below, speak to your doctor about laboratory tests to determine if you are deficient in this essential antioxidant.
- Dry skin, with or without age spots and wrinkles.
- Easy bruising is an early sign of deficiency.
- Slow wound healing, linked to poor collagen formation.
- Pain and swelling in the joints, also linked to poor collagen formation.
- Weak bones, fractures, or a recent diagnosis of osteoporosis.
- Bleeding gums and poor dental health.
- Hair that is dry, lackluster, and brittle.
- Body hair abnormalities including corkscrew-shaped hairs.
- Red spots or lines in the beds of fingernails.
- Frequent nosebleeds that are atypical for you.
- Recent diagnosis of anemia, linked to vitamin C’s crucial role in iron absorption.
- Persistent fatigue that is accompanied by depression or other mood changes. These are also symptoms of a vitamin D deficiency.
- Weight gain, linked to a lack of vitamin C supporting healthy metabolism function.
- Recurrent or multiple infections or colds due to poor immune system function.
A severe vitamin C deficiency can cause the disease scurvy. While rare in most populations in the United States, scurvy is generally brought on by not consuming enough vitamin C-rich foods. This condition can occur in as little as 30 days after little or no vitamin C is consumed. After a diagnosis of scurvy, patients are given vitamin C supplements, and a change in diet is recommended.
Causes and Risk Factors of Vitamin C Deficiency
The primary cause of a vitamin C deficiency is diet. However, there are certain groups that have been identified to be more prone to vitamin C deficiency or inadequacy.
- Smokers and those exposed to secondhand smoke
- Infants on a diet of evaporated or boiled milk
- Individuals that don’t eat a variety of foods
- Cancer patients
- Individuals with cachexia, a severe intestinal malabsorption condition
- Individuals with renal disease
Considerations and Side Effects
Vitamin C foods and supplements are generally considered safe for most people, as vitamin C has a low toxicity level and generally doesn’t cause severe adverse reactions—even at high doses. However, if you jump up your intake dramatically, you may experience:
- Abdominal cramps
There are additional concerns regarding the use of vitamin C for patients with kidney impairment on medications that contain aluminum compounds. A 2000-milligram dose of vitamin C may increase the amount of aluminum that is absorbed and cause an adverse effect, such as raising the risk of kidney stones. If kidney function is at all compromised, take large doses of vitamin C under medical advice only.