Vitamin C Benefits the Immune System — and So Much More

Abundant in a variety of fruits and veggies, plus found in skin care serums and anti-aging products alike, vitamin C is a powerful micronutrient and crucial part of the diet. From slowing down skin aging to reducing cholesterol levels, studies have found that vitamin C benefits many aspects of health, from the inside out.

A deficiency in this important vitamin can take a serious toll on your body, causing symptoms like impaired immunity, gingivitis and easy bruising. Conversely, getting enough may help ward off illness and infection, enhance iron absorption, and even reduce the risk of painful conditions like gout.

We know vitamin C may help reduce symptoms and shorten the duration of the common cold and viral pneumonia-related hospital stays. And some in the medical community believe vitamin C holds promise in helping to treat serious viral-related side effects of flu and other viruses.

Interestingly, a 2017 study outlined the case of a 20-year-old woman diagnosed with virus-induced acute respiratory distress syndrome, also known as ARDS. When mechanical ventilation failed, hospital doctors administered a high dose of IV vitamin C that was associated with “rapid resolution of lung injury” and full recovery.

It’s important to note that this was just one case study. And it doesn’t mean we should all seek out mega doses of vitamin C. But it does suggest we should invest more research to investigate how vitamin C and other natural methods could help assist in global outbreaks to possibly save lives.

Keep reading to learn more about the potential vitamin C benefits and side effects, plus how you can make sure to get in your daily dose with vitamin C foods and supplements.

What Is Vitamin C?

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that is found in many types of fruits and vegetables. It acts as an antioxidant to neutralize free radicals and reduce the risk of inflammation and disease.

Your body also uses vitamin C to synthesize important compounds like collagen, a type of structural protein that makes up connective tissue and aids in wound healing. Vitamin C is also needed for the production of other compounds, such as L-carnitine and neurotransmitters.

Ongoing research has uncovered a multitude of potential vitamin C benefits and has found that getting enough in your diet can help improve skin health, boost immunity and even protect against certain conditions.

Benefits

1. Holds Powerful Antioxidant Properties

Antioxidants are compounds that play a central role in health and disease. They help fight disease-causing free radicals, minimizing oxidative stress and damage to your cells. Studies show that antioxidants may also aid in the treatment and prevention of multiple chronic conditions, including heart disease, autoimmune disorders and even cancer.

Vitamin C acts as an antioxidant in the body, helping prevent the buildup of free radicals to protect your body against disease. This could have far-reaching benefits when it comes to disease prevention, with some studies suggesting that a higher intake of vitamin C-rich fruits and vegetables may be associated with a lower risk of many chronic conditions.

2. Helps Prevent Anemia

Anemia is a condition characterized by a lack of healthy red blood cells, resulting in anemia symptoms like fatigue, weakness and chest pain. Although there are many potential factors that can cause anemia, one of the most common is a deficiency in key micronutrients like vitamin B12 or iron.

Vitamin C can enhance iron absorption to help prevent iron-deficiency anemia. In fact, a study published in the American Journal of Clinical Nutrition found that taking vitamin C with a meal was able to increase iron absorption by up to 67 percent. For best results, combine a serving of iron-rich foods with some foods with vitamin C to bump up your iron intake.

3. Boosts Immunity

One of the most well-known benefits of vitamin C is its ability to improve immune health. In fact, loading up on vitamin C foods is often used as a first line of defense during cold and flu season.

Studies have repeatedly confirmed the immune-boosting benefits of vitamin C. A review published in the Annals of Nutrition & Metabolism showed that getting enough vitamin C may help reduce symptoms and shorten the duration of respiratory tract infections, such as the common cold. Plus, vitamin C may also help decrease the incidence of other conditions like pneumonia, malaria and diarrhea as well.

4. Improves Heart Health

Your heart is absolutely essential to overall health. As one of the most important organs in your body, your heart works tirelessly to supply your cells with oxygen and nutrients by pumping blood through your veins.

Incorporating more vitamin C foods into your diet may help protect the health of your heart and prevent heart disease. A review from the National University of Health Sciences made up of 13 studies showed that supplementing with 500 milligrams of vitamin C daily significantly reduced levels of LDL cholesterol and triglycerides.

Similarly, another human study from the University of Southampton found that a higher intake of vitamin C was associated with a lower risk of death from stroke or coronary heart disease.

5. Promotes Glowing Skin

Ascorbic acid, or vitamin C, is a common ingredient found in a wide assortment of skin care products and cosmetics alike. Thanks to its antioxidant content, vitamin C benefits skin health through several different mechanisms.

Because it’s involved in the synthesis of collagen, vitamin C is believed to help slow down skin aging and can also protect against skin damage and free radical formation caused by ultraviolet exposure.

Plus, there may also be some vitamin C benefits for skin lightening and hyperpigmentation; studies have shown that vitamin C may help suppress melanin production to prevent dark spots and patches.

6. Reduces Risk of Gout

Gout is a painful form of arthritis characterized by swollen and stiff joints. It’s caused by a buildup of uric acid in the joints and most commonly affects the foot and big toe.

Studies show that getting more vitamin C helps protect against gout. A study published in the Archives of Internal Medicine followed nearly 47,000 men over a 20-year period and found that a higher intake of vitamin C was associated with a lower risk of developing gout.

A review in 2011 had similar findings, reporting that vitamin C supplementation was able to significantly lower levels of uric acid in the blood, which may help reduce the risk of gout flare-ups.

Top Foods

There are plenty of foods high in vitamin C, making it super easy (and delicious) to get in your daily dose. Fruits and vegetables, in particular, are excellent ways to boost your intake.

Here are a few of the best sources of vitamin C:

Kiwi Fruit: 1 cup contains 164 milligrams (273 percent DV)
Bell Peppers: 1 cup, raw contains 120 milligrams (200 percent DV)
Orange: 1 cup contains 95.8 milligrams (160 percent DV)
Strawberries: 1 cup contains 89.4 milligrams (149 percent DV)
Papaya: 1 cup contains 86.5 milligrams (144 percent DV)
Pineapple: 1 cup contains 78.9 milligrams (131 percent DV)
Grapefruit: 1 cup contains 71.8 milligrams (120 percent DV)
Broccoli: ½ cup, cooked contains 50.6 milligrams (84 percent DV)
Brussels Sprouts: ½ cup, cooked contains 48.4 milligrams (81 percent DV)
Mango: 1 cup contains 45.7 milligrams (76 percent DV)
Tomatoes: 1 cup contains 18.9 milligrams (32 percent DV)
Spinach: 1 cup, cooked contains 17.6 milligrams (29 percent DV)

Dosage

The recommended intake of vitamin C can vary by age and gender. Here are the recommended dietary allowances for vitamin C according to the National Institutes of Health:

0–6 months: 40 milligrams daily
7–12 months: 50 milligrams daily
1–3 years: 15 milligrams daily
4–8 years: 25 milligrams daily
9–13 years: 45 milligrams daily
14–18 years: 75 milligrams daily for males, 65 milligrams daily for females
19+ years: 90 milligrams daily for males, 75 milligrams daily for females

Individuals who smoke need an additional 35 milligrams of vitamin C daily. Vitamin C needs also increase in women who are pregnant and breastfeeding to 85 milligrams and 120 milligrams, respectively.

Much like other antioxidants, such as astaxanthin or beta-carotene, vitamin C supplements are also available and can be found in vitamin C powder, tablet and capsule form. Possible vitamin C tablets benefits include increased immunity, better skin health and a reduced risk of deficiency.

However, unless advised by your doctor, it’s best to get your vitamin C from whole food sources rather than supplementation. Not only can these nutrient-dense foods provide an assortment of other important vitamins and minerals, but there is also a reduced risk of adverse side effects that may come with supplementation, like an increased risk of kidney stones in men.

There seems, though, to be no serious side effects even with high doses of vitamin C. With the exception of a slightly higher risk of kidney stones (in men only), most adults can safely take up to 2,000 milligrams per day of vitamin C and experience very mild stomach discomfort at most.

Deficiency Symptoms

A severe vitamin C deficiency can result in a condition called scurvy, which is caused by a disruption in the synthesis of collagen and connective tissues.

In the past, scurvy was incredibly common and even fatal. In fact, scurvy was a major cause of death for British sailors during the 18th century. Today, scurvy is less common but can be caused by underlying conditions that impair nutrient absorption, such as digestive disorders.

One study even found that vitamin C deficiency was detected in seven out of 10 patients with inactive Crohn’s disease, even though four had an adequate intake of vitamin C. Studies also have found that smokers may also be more susceptible to a vitamin C deficiency.

Scurvy can have some serious signs and symptoms, including:

Slow wound healing
Bleeding gums
Easy bruising
Fatigue
Swollen gums
Weakened immune system
Frequent nosebleeds
Dry, scaly skin
Swollen joints
Dry, splitting hair
Gingivitis

Treatment of scurvy involves either using a vitamin C supplement or increasing intake of vitamin C foods under the direction of a health care professional.

Vitamin C vs. Retinol

Vitamin C and retinol are two powerful anti-aging ingredients found in many skin care products. Retinol is actually a form of vitamin A, and like vitamin C, it’s found in both food and supplement form and can also be applied topically. Like vitamin C, retinol has been shown to stimulate collagen synthesis to help reduce skin aging and wrinkles.

There’s a common misconception that you shouldn’t combine a product containing retinol with vitamin C serum. However, a 2005 human study out of France found that applying a preparation containing both to the skin was effective in remedying aging and sun damage.

Instead of opting for vitamin C serum or retinol on its own, it’s best to look for a product that contains both to help maximize the anti-aging benefits of your skin care routine.

Vitamin C in Ayurveda and TCM

Vitamin C-rich fruits and vegetables are used extensively in Ayurveda and Traditional Chinese Medicine.

Lemons, for example, are believed to have detoxifying and cleansing properties and are said to stimulate fluid excretions in the lungs, flush out bile and promote the elimination of toxins from the body.

Similarly, oranges are thought to clarify the blood and cleanse the digestive system. They’re also used to reduce fatigue, increase strength and enhance immunity.

In Traditional Chinese Medicine, citrus fruit peels are also common ingredients used to improve both digestive and respiratory health. Mandarin orange peels, in particular, are believed to help relieve abdominal distension, bloating and gas by supporting better digestive health.

Recipes

Looking for some simple ways to take advantage of the many vitamin C benefits by upping your intake of vitamin C-rich foods? Here are a few easy recipes that you can try making at home:

Strawberry Spinach Salad with Poppy Seed Dressing
Honey Sriracha Roasted Brussels Sprouts
Crockpot Beef and Broccoli
Winter Fruit Salad
Quinoa Stuffed Peppers

Interesting Facts

Although the medicinal properties of fruits and vegetables high in vitamin C have been known for centuries, the magnitude of vitamin C benefits has come to light relatively recently.

In the 1700s, scurvy was one of the leading causes of death for British sailors during long voyages at sea. In 1747, however, scientist James Lind began conducting research on board a naval ship and discovered that drinking lemon juice was able to successfully treat scurvy due to its high content of vitamin C.

The vitamin itself was not discovered until 1912, though, and was first synthesized over two decades later in 1933. In fact, it was the first vitamin to be synthesized and was able to be mass-produced and sold as a dietary supplement shortly thereafter.

Side Effects

So can you overdose on vitamin C, and how much vitamin C is too much?

If getting your vitamin C from food sources alone, there is very little risk of getting too much vitamin C. For adults, the tolerable upper intake level for vitamin C is set at 2,000 milligrams daily, which is far more than you’ll get from vitamin C sources in the diet.

It also has a low toxicity and a vitamin C overdose is unlikely to cause serious effects on health, as excess amounts are excreted. Some common symptoms associated with a high intake of vitamin C include diarrhea, nausea and abdominal cramps.

Unless advised by your doctor, it’s always best to get your vitamin C from food sources rather than supplements. Not only does this maximize the potential vitamin C benefits, but it can also reduce the risk of adverse health effects associated with vitamin C supplementation, including a higher incidence of kidney stones.

Final Thoughts

Vitamin C is a water-soluble vitamin that acts as an antioxidant and is involved in the synthesis of collagen and other important compounds.
There are many vitamin C benefits for men and women, including improved skin health, immunity and heart health. It can also protect against disease and may help prevent anemia and gout.
Vitamin C can be found in many different fruits and vegetables, including kiwi fruit, bell peppers, oranges and strawberries.
A deficiency in vitamin C can lead to a condition called scurvy, which can cause symptoms like bleeding gums, fatigue and slow wound healing.
Although vitamin C supplements are available, it’s best to increase your intake through whole food sources as part of a healthy diet to take full advantage of the many powerful vitamin C benefits.