Vitamin C (ascorbic acid) is the only water-soluble vitamin outside the B-complex group. The human body can’t synthesize this nutrient, so consuming vitamin C foods or supplements is the only way to get it.
Let’s get familiar with this essential vitamin, its effects, sources, etc.
Vitamin C Benefits
The ascorbic acid benefits are many—from reducing inflammation to reducing the risk of particular health issues.
Let’s take a look at the details in the section below.
It Reduces Oxidative Stress
Foods that contain ascorbic acid are potent antioxidants. Vitamin C helps eliminate harmful free radicals from the body, preventing them from damaging cells and tissues and causing premature aging and various health issues.
It Reduces Common Cold Duration
Contrary to popular belief, vitamin C doesn’t directly treat nor prevent the common cold and flu. However, it can reduce cold and flu duration and prevent further complications (e.g., lung infections, pneumonia, etc.)
It Reduces Stroke Risk
According to research, individuals with high blood levels of vitamin C are 42% less likely to suffer a stroke than individuals with lower levels of this vitamin. They include those who consume plenty of vitamin C-rich foods like fruit and vegetables.
However, the research is conflicted about this vitamin C benefit. Furthermore, it’s still unclear whether the risk is reduced due to vitamin C or high fiber intake through fruit and vegetables.
It Prevents Premature Skin Aging
This is one of the vital vitamin C benefits for the skin. Due to its powerful antioxidant properties, this vitamin rejuvenates the skin by eliminating free radicals that contribute to skin damage and aging.
A large study examining over 4,000 women aged 40–74 concluded that women with higher vitamin C intake were less prone to wrinkling, dry skin, and premature skin aging. Furthermore, there’s some evidence that topical application of vitamin C can also effectively reduce wrinkles.
Ascorbic Acid Food Sources
Fruit and vegetables stand out as undoubtedly the richest food sources of vitamin C.
Let’s take a look at our vitamin C foods list and find out which items rank the highest.
The Australian native fruit, Kakadu plum (Terminalia ferdinandiana), is likely the richest source of vitamin C on our list. It contains over 100 times more vitamin C than oranges.
A 3.5-oz serving provides 5,300 mg (530% DV) of vitamin C.
Besides offering large amounts of vitamin C, this fruit is also rich in tocopherol, potassium, and lutein.
This white or deep-pink-fleshed tropical fruit originating from Central America is also one of the top vitamin C fruits. A single cup of raw guava offers 376.7 mg (628% DV) of vitamin C.
This fruit is an excellent antioxidant and has a significant role in lowering blood pressure, cholesterol levels, etc. It’s also a good dietary fiber, minerals, and vitamins A, E, and B source.
This cruciferous vegetable (raw) provides 39 mg (43% DV) of vitamin C per 1/2 cup. Thermal processing slightly increases the vitamin C value. So, cooked broccoli provides 51 mg (57% DV) of vitamin C per 1/2 cup.
Research shows that consuming vitamin C vegetables such as broccoli may help reduce oxidative stress, boost the immune system, and decrease the risk of cancer and cardiovascular diseases.
One cup of raw chopped kale provides 80.4 mg (89% DV) of vitamin C.
Cooking reduces kale’s vitamin C content to about 53 mg (59% DV) per cup. However, although they decrease vitamin C levels, boiling, frying, and steaming increase antioxidant release in kale.
Kale, which is also rich in vitamin K, lutein, and zeaxanthin, can help improve chronic inflammatory conditions.
Rose hip is a sweet and tangy wild rose fruit. Though small, it’s one of the foods highest in vitamin C, providing 541 mg (601% DV) of vitamin C per cup.
The high vitamin C content makes it excellent for maintaining healthy skin.
Lemons are so high in vitamin C that they served as the primary scurvy remedy and prevention among sailors in the 18th century. A single lemon provides 34.4 mg (38.2% DV) of vitamin C.
Oranges are also one of the well-known good sources of vitamin C. One medium orange provides 70 mg (78% DV) of vitamin C. Orange juice is an even better source, offering 70 mg (103% DV) per cup.
One cup of papaya contains 87 mg (97% DV) vitamin C, besides other nutrients. Just like other vitamin-C-rich foods, it offers a host of ascorbic acid benefits like inflammation reduction, blood pressure regulation, etc.
Strawberries are one of the world’s most adored vitamin C fruits, providing 89 mg (99% DV) of vitamin C per cup. Just like other foods in this category, this berry effectively reduces cholesterol and cardiovascular diseases.
According to a study, three cups of fresh strawberries can reduce LDL cholesterol by 11%.
Green Chili Peppers
These flavorful peppers are some of the foods high in vitamin C highly popular in Indian cuisine. Besides providing delicious aromas, they also offer generous amounts of ascorbic acid. A single pepper provides 109 mg (121% DV) of vitamin C.
Green chili peppers are also an excellent natural source of iron and inflammation-reducing capsaicin.
Sweet Yellow Peppers
Sweet peppers or bell peppers are also some of the high vitamin C foods. Their vitamin C content depends on their maturity—the more mature they are, the richer they are in this essential nutrient.
A typical serving of 10 pepper strips provides 95.7 mg (106% DV) of vitamin C.
Such high vitamin C content makes it excellent for cataract progression prevention. A large study examining 300 women showed that high vitamin C intake reduces the risk of cataract progression by 33%.
There might be some truth in the saying, “an apple a day keeps the doctor away.” This healthy, widely available fruit ranks relatively high on the vitamin C foods list, as one cup of chopped apples provides 5.75 mg (10% DV) of vitamin C.
Talk about a highly nutritious fish, talk about salmon. This fish is one of the rare animal products containing this vitamin. Only 0.5 fillet of cooked Atlantic salmon can provide you with 6.59 mg (7% DV) of vitamin C.
This popular sweet-scented aromatic spice is one of the highest vitamin C foods amongst culinary herbs. Surprisingly, fresh thyme provides three times more vitamin C than oranges.
As little as 1 oz of thyme contains 45 mg (50% DV) of vitamin C, making it an excellent immunity booster and respiratory infection remedy.
Natto is one of the most popular Japanese foods that contain ascorbic acid. This uniquely textured meal made with fermented soybeans offers 22.8 mg (25% DV) of vitamin C per cup.
Natto is also packed with various other nutrients (e.g., proteins, calcium, copper, iron, manganese, and magnesium, etc.).
Bacon and Tomato Salad Dressing
Surprisingly, salad dressing is also one of the good sources of vitamin C, providing 21.1 mg (35% DV) of vitamin C per cup.
It’s also a good source of vitamin K, folate, potassium, etc.
Vitamin C Deficiency
Since vitamin C is a water-soluble vitamin, it doesn’t get stored in the body. As a result, we must regularly take it from external sources, preferably food.
Let’s see what risks failing to include adequate amounts of vitamin C foods such as those listed in the section above into your diet may pose.
Vitamin C plays a vital role in synthesizing collagen, a protein abundant in the skin, in charge of its smoothness and elasticity. The lack of it makes skin dry and damaged.
In cases of long-term low vitamin C levels (typically 3–5 months), keratosis pilaris can occur. This condition is characterized by bumpy skin on the thighs, buttocks, or backs of the arms.
However, keratosis pilaris alone isn’t enough for a vitamin C deficiency diagnosis since this condition has many other potential causes.
Coiled Body Hair
Vitamin C deficiency is associated with bent or coiled body hair due to defects in the hair’s protein structure that occur as it grows out. Such hairs are likely to fall out quickly, so this symptom is often overlooked.
Adequate vitamin C intake usually resolves this hair abnormality within a month.
Red Hair Follicles
Perifollicular hemorrhage is one of the characteristic vitamin C deficiency symptoms. It’s characterized by red spots caused by breaking of blood vessels surrounding the follicle that become fragile due to vitamin C deficiency.
This condition is characterized by thin and brittle nails, concave in shape. Though spoon-shaped nails are more characteristic of iron deficiency anemia, they’re also associated with a lack of vitamin C.
Vitamin C plays a crucial role in bone formation. Low levels, therefore, lead to bone loss and increase the risk of osteoporosis and fracturing.
Children may be particularly affected by ascorbic acid deficiency, as their bones are still developing.
Low vitamin C levels imply impaired production of collagen, which helps strengthen blood vessels. As a result, the blood vessels under the skin become weak and rupture, creating bruises either in the form of small dots or covering larger areas of the body.
Slow Wound Healing
Impaired collagen production also affects the speed of wound healing, slowing it down. This is one of the typical signs of the long-term lack of exposure to adequate amounts of ascorbic acid food (e.g., oranges, broccoli, kale, etc.).
A severe lack of the vitamin may even result in the reopening of old wounds, increasing the risk of infection.
Bleeding Gums and Tooth Loss
Swollen, inflamed, and bleeding gums are one of the most common vitamin C deficiency symptoms. In severe cases, gums may become purple and rotten and even lead to tooth loss.
Painful and Swollen Joints
Painful swelling caused by bleeding within the joints is also one of the common deficiency symptoms. It occurs due to impaired collagen synthesis.
The swelling and pain can get so severe as to cause limping and difficulty walking.
Impaired Immune Function
The lack of ascorbic acid in food is also associated with a weakened, poorly functioning immune system and a higher risk of infections.
Iron Deficiency Anemia
Vitamin C is necessary for iron absorption, so vitamin C deficiency and iron deficiency anemia usually cooccur. Additionally, ascorbic acid deficiency increases the risk of bleeding, thereby increasing the risk of anemia.
The signs of iron deficiency anemia include fatigue, difficulty breathing upon exertion, paleness, headaches, spoon-shaped nails, dry skin, and hair.
Fatigue and Mood Changes
These subtle symptoms are one of the earliest symptoms of vitamin C deficiency. They’re also the easiest to treat. Including enough foods with vitamin C or taking a high-dose vitamin C supplement solves these problems within days.
Who Is at Risk of Vitamin C Deficiency?
Some individuals are more prone to developing this type of deficiency than others, and they include:
- People with limited access to vitamin C foods
- Individuals following restrictive diets
- Individuals with particular food allergies
- Heavy drinkers
- Eating disorder patients (e.g. anorexia)
- Severe mental disorder patients
- Dialysis patients
- Individuals with gastrointestinal issues (e.g. inflammatory bowel disease), etc.
The Recommended Daily Intake of Vitamin C
Vitamin C is an over-the-counter drug, but that doesn’t mean its dosage is arbitrary. Let’s look at the table and discover how much of this vitamin is necessary for optimal functioning.
|0–6 months||40 mg (AI)||40 mg (AI)|
|7–12 months||50 mg (AI)||50 mg (AI)|
|1–3 years||15 mg||15 mg|
|4–8 years||25 mg||25 mg|
|9–13 years||45 mg||45 mg|
|14–18 years||75 mg||65 mg||80 mg||115 mg|
|19+ years||90 mg||75 mg||85 mg||120 mg|
Interestingly, smokers need a higher daily dose of vitamin C than non-smokers. They require an additional 35 mg a day.
Tolerable Upper Limit
Though consuming plenty of vitamin C may produce many benefits, it’s essential not to go overboard with the dosage. Tolerable upper intake shows the highest vitamin C dosage you can take without facing a health risk.
Let’s take a look.
|Age Group||Tolerable Upper Limit|
|1–3 years||400 mg/day|
|4–8 years||650 mg/day|
|9–13 years||1,200 mg/day|
|14–18 years||1,800 mg/day|
|19+ years||2,000 mg/day|
Vitamin C Overdose
It’s virtually impossible to overdose on vitamin C through food. This notion is typically related to supplements intake.
However, even the excessive consumption of supplements is characterized by low toxicity. The most common symptoms of taking too much vitamin C (typically over 2,000 mg for healthy adults) include:
- Abdominal cramping
- Sleep disturbances
Excessive vitamin C intake can enhance iron absorption, so hemochromatosis patients should be extra careful with ascorbic acid supplements to avoid iron overload, detrimental to the heart, thyroid, liver, pancreas, and central nervous system.
Interactions With Medications
Vitamin C can interact with various medications. So, if you intend to start a vitamin C supplement while taking any of the medications listed below, it’s essential to consult your doctor first.
Medications Containing Aluminium
Vitamin C can increase the absorption of aluminum, increasing the risk of aluminium toxicity.
Radiation Therapy and Chemotherapy Medications
Research concerning the interaction of vitamin C supplements and cancer therapy is conflicting.
Some studies indicate that vitamin C may reduce the efficacy of chemotherapy drugs due to its antioxidant properties. Antioxidants could protect tumor cells from the effects of radiation and chemotherapy.
On the other hand, there are also studies suggesting that vitamin C can enhance the effectiveness of cancer treatment. It can protect body tissues against radiation damage and chemotherapy drugs.
Therefore, it’s best to discuss vitamin supplementation with your oncologist, especially if taking high-dose vitamin C.
Taking oral contraceptives or hormone replacement therapy with vitamin C supplements can increase estrogen levels.
Protease inhibitors are used in the treatment of viral diseases. Vitamin C supplement intake decreases the efficacy of this class of drugs.
Statins and Niacin
Vitamin C may increase HDL levels, thereby reducing the efficacy of these drugs.
High vitamin C intake might decrease the efficacy of anticoagulants.
A balanced diet is essential for maintaining adequate vitamin C levels, thereby supporting optimal health. Various vitamin C foods, especially the ones listed above (e.g., Kakadu plum, bell peppers, green chili peppers, thyme, etc.), can help with this tremendously.
What is vitamin C?
Vitamin C (ascorbic acid) is the only water-soluble vitamin besides the B-complex. It’s an essential vitamin the body can’t produce, so we have to take it through food or supplements.
This vitamin plays a role in the body’s optimal function—it supports collagen biosynthesis and protein metabolism. It’s also a powerful antioxidant, and it helps the body absorb iron from plant-based foods.
Is 1,000mg of vitamin C too much?
For most healthy adults, a daily vitamin C dose of 1,000 mg isn’t too much. This is because the tolerable upper limit for adults is 2,000 mg per day.
This amount of vitamin C could be too much for children under 9.
Which vegetables contain vitamin C?
Many vegetables are excellent vitamin C sources:
- Raw mustard spinach (217% DV per cup)
- Raw sweet yellow peppers (152% DV per 1/2 cup)
- Raw green chili peppers (121% DV per pepper)
- Raw sweet red peppers (106% DV per 1/2 cup)
- Raw kale (89% DV per cup)
- Raw red chili peppers (72% DV per pepper)
- Cooked broccoli (58% DV per 1/2 cup)
- Brussel sprouts (54% DV per 1/2 cup), etc.
Which fruit has more vitamin C than an orange?
- Kakadu plum has over 100 times more vitamin C than oranges.
What food is highest in vitamin C?
The Kakadu plum (Terminalia ferdinandiana) is the food with the highest known concentration of vitamin C. A single plum provides 481 mg (534% DV) of vitamin C, while a 3.5-oz serving packs a whopping 5,300 mg (5,888% DV) of this vitamin), making it the richest of vitamin C foods.