The citrus-fruit vitamin is known for immune-boosting properties, but it has a host of other health benefits. It’s found in many food sources, especially fresh fruits and vegetables, but some are higher than others.
Research-Proven Health Benefits of Vitamin C
Vitamin C is a water-soluble vitamin that is a potent antioxidant. It is an essential vitamin and must be provided from dietary sources since the body cannot make it on its own.
It has numerous health benefits that are backed by solid research.
Boosts Immunity & Fights Infection
Perhaps its most popular use, vitamin C is a potent immune booster. It supports several key aspects of the immune system’s function.
As a nutrient, vitamin C can boost the production of white blood cells that fend off infections and help to fight them once you get them. (1)
It also functions as an antioxidant to reduce the cellular and tissue damage you could get from free radicals. Vitamin C also supports healthy skin and can promote better wound healing. (2)
Reduces Risk of Chronic Disorders
As an antioxidant, vitamin C fights cellular damage in the body that can result in breakdown from free radicals and oxidative stress. Chronic disorders are associated with inflammation and damage from these free radicals.
Many chronic diseases are tied to oxidation in the body, such as cancer, autoimmunity, cataracts, heart disease, neurodegenerative disorders, and rheumatoid arthritis. (3)
Regularly eating vitamin C or taking supplements is associated with a boost in blood antioxidants by as much as 30 percent, which also reduces the occurrence of inflammation. (4)
Lowers Blood Pressure & Supports Heart Health
More than 30 percent of Americans have high blood pressure, which increases the risk of heart disease. (5) Vitamin C helps to normalize blood pressure by relaxing blood vessels. This effect is seen in both healthy individuals and those who already have elevated levels.
Heart disease is the number one cause of death across the world, and vitamin C also helps to balance cholesterol levels. While cholesterol in and of itself doesn’t cause heart disease, when LDL levels become elevated and get oxidized, they can increase plaque build-up in the arteries.
Vitamin C helps to balance cholesterol and fights oxidative stress, therefore, having a protective effect on artery health.
Vitamin C can also help to lower triglyceride levels, which are also associated with heart disease risk factors. The protective benefits of this vitamin were shown by just taking 500 milligrams daily.
Prevents Gout & Reduces Uric Acid Levels
While osteoarthritis and rheumatoid arthritis are more well-known, gout is another form of arthritis that impacts around four percent of American adults. (6)
Like other forms of arthritis, gout causes painful inflammation and swelling in joints, primarily in that of the big toe. Pain attacks can come on without warning and make it debilitating to walk or stand.
Gout is caused by elevated levels of uric acid, which is a waste product in the body. When levels get too high, it crystallizes, resulting in painful joint deposits in the toes.
Vitamin C helps to reduce uric acid levels and can reduce the risk of developing gout by more than 40 percent. (7)
Supports Bone Health
Bones are constantly in a state of being remodeled, and when we don’t have the right nutrients, they can become weak and brittle. Bone density loss is a common aging problem, especially in women.
Vitamin C helps defend bone density by improving calcium absorption, but also by reducing oxidative stress in the body. (8)
If you already have brittle bones or want to protect against osteoporosis, 1,000 milligrams of vitamin C daily is the study-suggested dose for optimal bone health.
Promotes Mental Health & Mood Balance
Vitamin C can boost mental health, ease depression, and provide balance for emotional wellness. In studies of people who are hospitalized, vitamin C supplementation is able to reduce mood disturbances by 34 percent.
At its root, depression is a condition highly influenced by inflammatory processes. Vitamin C is a potent antioxidant that can help curb inflammation in the body and may be able to reduce symptoms.
Defends Against Anemia & Helps With Iron Absorption
Without iron, the blood is unable to carry enough oxygen throughout the body. It’s also required for making red blood cells and preventing anemia.
But iron is a mineral that is one of the more common deficiencies, and even if a person isn’t deficient, low levels can have a critical role in fatigue and metabolism.
Vitamin C can help increase absorption of iron from food sources and from supplements. It’s especially effective in optimizing absorption of iron from plant-based sources. (9)
Eating 100 milligrams of vitamin C with any iron sources increases absorption by nearly 70 percent. This is especially important for anyone dealing with anemia.
Protects Brain Health & Promotes Cognition
Dementia affects more than 35 million people in the world and involves symptoms like poor thinking, memory problems, and a lack of connection to daily life. (10) It is most commonly seen in older individuals.
Research suggests that at the root of dementia are stress and inflammation factors that affect the nervous system and increase the risk of brain problems.
Vitamin C, as an antioxidant, can help to lower inflammation levels throughout the body and may be protective of brain health. Low levels have also been associated with poor cognition.
Those who have dementia are shown to have too little vitamin C, so supplementing with this nutrient or increasing fresh foods that are high in vitamin C can have a protective effect on overall brain and nervous system health.
26 Foods High in Vitamin C
While you can get vitamin C from supplements, it’s also abundant in fresh foods. These are the foods with the highest levels.
- Thyme: This herb has three times more vitamin C than citrus fruits, gram for gram. A single ounce provides half the day’s requirements for vitamin C.
- Acerola Cherries: A one-half cup serving of these contains over 900% daily value with a whopping 820 milligrams of vitamin C.
- Blackcurrants: Just a half cup of this fruit provides 112% daily value of vitamin C, plus specialized antioxidants make them effective for reducing the risk of chronic and neurodegenerative disorders.
- Parsley: Two tablespoons provide more than 10% daily value of vitamin C and it’s also an excellent source of plant-based iron.
- Australian Plums: This Australian superfood contains almost 500 milligrams per plum, which is more than 530% daily value. It’s also a good source of potassium, vitamin E, and other antioxidants.
- Mustard Spinach: One cup of this green provides more than 200% daily value of vitamin C, and it is also an excellent source of fiber and folate.
- Kale: A single cup of this dark leafy green provides 90% daily value of vitamin C, and it’s also packed with vitamin K, carotenoids, and fiber.
- Green Chili Peppers: A single green chili pepper has more than 120% daily value of vitamin C, along with capsaicin, which is another way to lower inflammation levels.
- Red Chili Peppers: One red chili pepper contains 72% daily value of vitamin C and has special fat-burning properties that green chilis don’t contain.
- Broccoli: This cruciferous vegetable provides more than 100% daily value from a single cup. It is also widely considered as an anti-cancer food that can decrease inflammatory markers by nearly 50 percent.
- Guavas: This Central and South American fruit has more than 140% daily value of vitamin C and is also a source of lycopene (the antioxidant that is also found in tomatoes).
- Green Bell Peppers: A one-cup serving provides 100% daily value of vitamin C.
- Brussels Sprouts: These mini-cabbages contain 108% daily value in a single cup serving. They’re also an excellent source of fiber, potassium, folate, vitamin K, manganese, and vitamin A.
- Persimmons: A single American persimmon contains almost 20% daily value of Vitamin C.
- Lemons: The juice of this fruit is a vitamin-C rich antioxidant that contains half a day’s vitamin C in just half a juiced lemon.
- Sweet Yellow Peppers: With more than 150% daily value of vitamin C in just a half cup, sweet yellow peppers are also a superfood for healthy eyes.
- Papaya: One cup of papaya contains 100% daily value for vitamin C, plus it’s also an anti-inflammatory superfood that can protect against Alzheimer’s.
- Strawberries: One cup of strawberries provides 100% daily value for vitamin C, plus a host of other flavonoids, fiber, folate, and nutrients that fight cancer, dementia, diabetes, and heart disease.
- Kiwifruit: Just a single kiwi contains 80% daily value of vitamin C, plus other antioxidants and fiber.
- Lychees: One cup of lychees, a tropical fruit from the soapberry family, contains more than 150% daily value of vitamin C.
- Rose Hips: A small, tangy fruit that is part of the rose plant, a small serving contains more than 100% daily value.
- Oranges: A single medium orange is packed with nearly 80% daily value of vitamin C.
- Grapefruit: One grapefruit half has 73% daily value of vitamin C.
- Sweet Red Peppers: Another variety in the pepper family, sweet red peppers contain more than 300% of the recommended daily intake in a one-half cup serving.
- Cantaloupe: One cup of this melon fruit contains 98% daily value of vitamin C, plus a full day’s serving of vitamin A, too.
- Tomatoes: One full-sized tomato contains nearly half of a day’s worth of vitamin C, plus other antioxidants like lycopene which support heart health and male fertility.
Symptoms of Low Vitamin C
If you don’t get enough vitamin C from foods or supplements, you’re at risk for developing a host of symptoms. The most common associated with low vitamin C intake include:
- Rough, bumpy skin (keratosis pilaris)
- Dry or damaged skin
- Easy bruising
- Poor wound healing
- Joint pain and swelling
- Weak and brittle bones
- Bleeding gums and periodontal disease
- Lowered immunity and increased infections
- Iron-deficiency anemia
- Low mood
- Unexplained weight gain
Side Effects of Too Much Vitamin C
While too little vitamin C can cause problems, there are also issues associated with consuming or taking too much. Toxicity with vitamin C isn’t common since it is a water-soluble nutrient that is excreted in the urine when levels are higher than needed.
All cases of excess vitamin C happen in response to supplementation, which is why it’s important to check with your doctor on dosing and frequency.
These are the top two problems associated with too much vitamin C supplementation.
Digestive Upset: Consuming more than 2,000 milligrams per day can lead to nausea, diarrhea, and acid reflux.
Kidney Stones: When you take too much vitamin C, it is eliminated from the body via the kidneys and urine. But this waste contains oxalate, which can crystallize and lead to the development of kidney stones.
How to Supplement with Vitamin C
If you do want to take vitamin C supplements, be sure to choose a high-quality version. You can get vitamin C in powder and capsule form. If you are allergic to or sensitive to corn, be sure to choose a supplement that is sourced from tapioca, since most are derived from corn products.
The recommended daily intake to avoid deficiency is between 100 and 200 milligrams. Most people can get this from dietary sources alone, as evidenced above by the many foods that are rich in this nutrient.
If you don’t eat a lot of fresh fruits and vegetables, you might need to supplement, but in order to avoid excess amounts, limit intake to 1,000 milligrams per day. If you’re sick or rundown, taking 2,000 milligrams a day is considered to be the tolerable upper limit.
Some sources on the internet suggest a vitamin C flush, where you take more than 5,000 milligrams of vitamin C — but this is not recommended since it increases oxalate in the body and could strain the kidneys or lead to the formation of kidney stones.
Aimee McNew, MNT, CNTP, is a certified nutritionist who specializes in women’s health, thyroid problems, infertility, and digestive wellness. She ate her way back to health using a Paleo diet, lost 80 pounds, and had a healthy baby after numerous miscarriages. She focuses on simple nutrition practices that promote long-lasting results.