vitamin C

Foods Richest in vitamin C

About vitamin C

Basic description

Vitamin C may be the most familiar of all of the nutrients. Although most adults would be hard pressed to name a good food source of biotin or riboflavin, most everyone can name citrus fruits as good sources of vitamin C. It is also a commonly used nutritional supplement.

The first use of modern scientific methods to assess disease treatment was when the British navy used foods containing vitamin C (although the vitamin itself would remain undiscovered for nearly two centuries) to prevent scurvy among sailors. You could make a good case that this nutrition experiment is among the most important scientific findings in human history.

Despite the familiarity of the U.S. public with vitamin C and the popularity of vitamin C supplements, food intake of vitamin C by the average U.S. adult is not much higher than the Dietary Reference Intake (DRI) level. For men in the U.S. twenty years and older, this average is 96 milligrams per day, and for women in the U.S. twenty years and older, it is 82 milligrams per day. (The DRIs for these two groups are 90 milligrams and 75 milligrams, respectively.) So even though U.S. adults are averaging adequate intake of vitamin C intake from their food, the amount is not as high as some people might expect given widespread familiarity and interest in vitamin C.

Among WHF foods, 27 qualify as excellent vitamin C sources. Six of those provide a full day’s requirement in a single serving. Another 14 rank as very good, and 14 as good, giving ample variety for building a vitamin C-sufficient meal plan.

Role in health support

Protection against excess free radicals

Vitamin C is probably best known as an antioxidant. This is a word that we use frequently but don’t always stop to think about in terms of its meaning. Antioxidants are forms of molecules that help keep chemical reactions in our body in check. In particular, antioxidants help prevent excessive activity on the part of free radical molecules. (Free radicals are forms of molecules that tend to be very reactive, and too many free radicals in the wrong place at the wrong time can do damage to our cells and tissue.) Vitamin C and other antioxidants help prevent that damage. Damage to the lens of the eye, damage to molecules circulating around in our bloodstream, and damage to genetic material (DNA) in our cells are all examples of damage that have been shown to be prevented under certain circumstances by vitamin C.

One interesting application of vitamin C as an antioxidant is its ability to transform iron into a state that is better absorbed in the intestine. Including vitamin C-rich foods in recipes with your best iron sources can potentially be a way to enhance iron absorption.

Collagen

Vitamin C is required to produce collagen, a protein that plays a critical role in the structure of our bodies. Collagen is the framework for our skin and our bones, and without it, we would quite literally fall apart.

This is the pathology of scurvy, the disease of severe vitamin C deficiency. Affected individuals lose teeth, hemorrhage easily, and suffer bone fragility from collapsing collagen structures. Prevention requires surprisingly little. As established over two centuries ago, a single lime per day typically suffices. Dozens of WHF foods match or exceed a lime’s vitamin C content per serving.

Brain health

Vitamin C is necessary to make certain neurotransmitters. These neurotransmitters are the signals that carry thoughts, feelings, and commands around our brains and throughout our nervous system.

In particular, we need vitamin C to produce serotonin, a hormone that plays a critical role in wide variety of body systems, including the nervous system, endocrine system, immune system, and digestive system. Many of our moods, daily bodily rhythms (including sleep-wake cycles), and experiences of stress and pain have serotonin included as a factor in their occurrence. Some of the most commonly used prescription medications for depression (SSRIs, or Selective Serotonin Reupdate Inhibitors) also target this hormone. While we are not suggesting that dietary intake of vitamin C will automatically improve the quality of any experiences described above, we do recommend that you include vitamin C-rich foods on a daily basis as part of your overall well-being.

Summary of food sources

The best food sources of vitamin C share one trait: all are plant foods. Most animals synthesize vitamin C endogenously (humans, primates, and guinea pigs are notable exceptions), but only plants accumulate it in concentrations high enough to serve as a dietary source.

Probably most of you associate citrus fruits with vitamin C. This is not a myth—all of our listed citrus fruits (orange, grapefruit, lime, and lemon) are excellent sources of vitamin C.

Many non-citrus fruits are highly rated sources, as well. Papaya, strawberries, pineapple, kiwifruit, cantaloupe, and raspberries are also excellent vitamin C sources. Cranberries, blueberries, and watermelon are examples of very good sources, while apples, pears, and bananas are in the good category. You should expect almost any fresh fruit to be a good, very good, or excellentsource of dietary vitamin C.

In addition, many vegetables contain vitamin C. All of the greens on our website are excellent sources of vitamin C. We are big fans of green leafy vegetables as sources of many nutrients and encourage their inclusion in daily diets. Our 3-Minute Swiss Chard is an easy and tasty recipe to get you started.

Many of the cruciferous vegetables are excellent sources of vitamin C. These foods have many potential health benefits and are the focus of many of our recipes. Very good sources of vitamin C in the vegetable group include summer and winter squash, green beans, and carrots.

Herbs and spices contribute more vitamin C than might be expected. A single WHF serving of parsley provides over half the recommended daily amount.

In case you are feeling lost in the flurry of good vitamin C sources, let’s take a step back and make this easy. If you are getting two to three servings of fruit per day, and three to five servings of vegetables, you are almost certainly getting enough dietary vitamin C. If you find yourself worried, make sure you get a serving of fresh green leafy vegetables daily, since this amount will provide you with over one-third of the requirement in one sitting.

Nutrient rating chart

Introduction to nutrient rating system chart

Read more background information and details of our rating system

WHF ranked as quality sources of
vitamin C

Food

Serving
Size

Cals

Amount
(mg)

DRI/DV
(%)

Nutrient
Density

World’s
Healthiest
Foods Rating

Papaya

1 medium

118.7

168.08

224

34.0

excellent

Bell Peppers

1 cup

28.5

117.48

157

98.9

excellent

Broccoli

1 cup

54.6

101.24

135

44.5

excellent

Brussels Sprouts

1 cup

56.2

96.72

129

41.3

excellent

Strawberries

1 cup

46.1

84.67

113

44.1

excellent

Pineapple

1 cup

82.5

78.87

105

22.9

excellent

Oranges

1 medium

61.6

69.69

93

27.2

excellent

Kiwifruit

1 2 inches

42.1

63.96

85

36.5

excellent

Cantaloupe

1 cup

54.4

58.72

78

25.9

excellent

Cauliflower

1 cup

28.5

54.93

73

46.2

excellent

Kale

1 cup

36.4

53.30

71

35.1

excellent

Cabbage

1 cup

43.5

51.60

69

28.5

excellent

Bok Choy

1 cup

20.4

44.20

59

52.0

excellent

Grapefruit

0.50 medium

41.0

44.03

59

25.8

excellent

Parsley

0.50 cup

10.9

40.43

54

88.7

excellent

Turnip Greens

1 cup

28.8

39.46

53

32.9

excellent

Beet Greens

1 cup

38.9

35.86

48

22.1

excellent

Mustard Greens

1 cup

36.4

35.42

47

23.4

excellent

Collard Greens

1 cup

62.7

34.58

46

13.2

excellent

Raspberries

1 cup

64.0

32.23

43

12.1

excellent

Swiss Chard

1 cup

35.0

31.50

42

21.6

excellent

Tomatoes

1 cup

32.4

24.66

33

18.3

excellent

Lemons and Limes

0.25 cup

13.4

23.61

31

42.2

excellent

Spinach

1 cup

41.4

17.64

24

10.2

excellent

Asparagus

1 cup

39.6

13.86

18

8.4

excellent

Sea Vegetables

1 TBS

10.8

12.16

16

26.9

excellent

Fennel

1 cup

27.0

10.44

14

9.3

excellent

Thyme

2 TBS

4.8

7.68

10

38.0

excellent

Sweet Potato

1 cup

180.0

39.20

52

5.2

very good

Winter Squash

1 cup

75.8

19.68

26

6.2

very good

Green Peas

1 cup

115.7

19.56

26

4.1

very good

Blueberries

1 cup

84.4

14.36

19

4.1

very good

Cranberries

1 cup

46.0

13.30

18

6.9

very good

Watermelon

1 cup

45.6

12.31

16

6.5

very good

Green Beans

1 cup

43.8

12.13

16

6.7

very good

Summer Squash

1 cup

36.0

9.90

13

6.6

very good

Carrots

1 cup

50.0

7.20

10

3.5

very good

Plum

1 2-1/8 inches

30.4

6.27

8

5.0

very good

Garlic

6 cloves

26.8

5.62

7

5.0

very good

Basil

0.50 cup

4.9

3.82

5

18.8

very good

Dill

0.50 cup

1.9

3.78

5

47.5

very good

Romaine Lettuce

2 cups

16.0

3.76

5

5.6

very good

Potatoes

1 cup

160.9

16.61

22

2.5

good

Avocado

1 cup

240.0

15.00

20

1.5

good

Onions

1 cup

92.4

10.92

15

2.8

good

Banana

1 medium

105.0

10.27

14

2.3

good

Apple

1 medium

94.6

8.37

11

2.1

good

Pear

1 medium

101.5

7.65

10

1.8

good

Beets

1 cup

74.8

6.12

8

2.0

good

Leeks

1 cup

32.2

4.37

6

3.3

good

Apricot

1 whole

16.8

3.50

5

5.0

good

Celery

1 cup

16.2

3.13

4

4.6

good

Cucumber

1 cup

15.6

2.91

4

4.5

good

Peppermint

2 TBS

5.3

2.42

3

10.9

good

Cilantro

0.50 cup

1.8

2.16

3

28.2

good

World’s Healthiest
Foods Rating

Rule

excellent

DRI/DV>=75% OR
Density>=7.6 AND DRI/DV>=10%

very good

DRI/DV>=50% OR
Density>=3.4 AND DRI/DV>=5%

good

DRI/DV>=25% OR
Density>=1.5 AND DRI/DV>=2.5%

Impact of cooking, storage and processing

The same electron-donating capacity that makes vitamin C an effective antioxidant also makes it vulnerable to oxidation by heat, atmospheric oxygen, and prolonged storage. This chemical instability is a practical argument for consuming vitamin C-rich foods as fresh and minimally processed as possible.

The vitamin C content of food will start to decline as soon as it is picked, even though this decline can be slowed down and minimized by cooling and retention of the food in its whole form. But a fresh, vitamin C-rich vegetable like broccoli—if allowed to sit at room temperature for 6 days—can lose almost 80% of its vitamin C. That potential vitamin C loss is one of the reasons it is so important to store broccoli (and all other vitamin C-rich foods) according to the methods that we describe in our individual food profiles. All of our food profiles include sections on How to Select and Store, and for each food we provide you with exact storage times and conditions that will help minimize nutrient loss from each food.

Long-term storage of vegetables can cost a significant amount of vitamin C. Kept frozen for a year, kale can lose half its vitamin C or more. Canning is even more detrimental, with 85% of the original vitamin C lost over the same year.

Cooking reduces vitamin C content in most foods, but losses vary substantially by method. Basket-steaming broccoli for 15 minutes reduces vitamin C by roughly one-quarter. Limiting steaming time to 5 minutes preserves significantly more.

Risk of dietary deficiency

As described earlier, the average dietary intake for vitamin C in the United States is just above the Dietary Reference Intake (DRI) level for both adult men and adult women. From this standpoint, U.S. adults aren’t at significant risk for vitamin C deficiency. However, average total calorie intake in the U.S. also tends to be too high, and while we may be doing okay in terms of our average vitamin C intake, we may also be overeating in order to do so. Whole, natural foods—especially fresh vegetables—can play a major role in providing ample vitamin C without increasing the risk of overeating. It’s one of the reasons we recommend this food group so highly.

At the risk of oversimplifying, if you are eating multiple servings of fresh fruits and vegetables every day, you are very likely to be getting enough vitamin C.

Other circumstances that might contribute to deficiency

Since smoking increases free radical damage, smokers will need more dietary vitamin C. The National Academy of Sciences recommends that smokers get an extra 35 mg of vitamin C every day, about the amount found in one-half of a medium orange.

Relationship with other nutrients

Vitamin C can increase the absorption of iron (especially the iron found in plant foods) and may help lower the risk of dietary iron deficiency. You’ll sometimes see us recommending the additional of a vitamin C-rich food to meals and recipes for this reason.

Antioxidants in foods tend to work together in important and synergistic ways to provide protection against free radical damage. The most well-known of these connections is that between vitamin E and vitamin C. Specifically, vitamin C helps to protect vitamin E in people, such as smokers, who have chronic overproduction of free radicals.

Similarly, we see the flavonoid class of plant-based antioxidants helping to make the free radical protection from vitamin C that much stronger. This is great news, given that the foods that are most flavonoid-rich also tend to be among our better vitamin C sources. This synergistic protection is but one of many potential explanations for why the health benefits of plant-based diets cannot be replicated by nutrient supplements.

A great example of vitamin C and flavonoids in a whole, natural food is fresh oranges. In this fruit, most of the vitamin C is found in the watery orange-colored portions, while many of the flavonoids are found in the white-colored linings and section dividers. (This distribution of vitamin C and flavonoids in oranges is one of the reasons that it can be helpful to consume the “pulp” along with the juice if you decide to consume a processed juice version of this food.)

Risk of dietary toxicity

The National Academy of Sciences has established a Tolerable Upper Intake Level (UL) of 2000 mg per day for adults. While it is plausible that in rare situations—particularly with a rich intake of citrus juices—an individual could be above this UL from foods alone, we are not aware of any evidence to suggest that vitamin C intake from foods ever is responsible for toxicity symptoms.

Disease checklist

• Common cold
• Scurvy
• Capillary fragility
• Asthma
• Gingivitis
• Gout
• Musculoskeletal injury
• High blood pressure
• Seasonal allergies
• Smoking

Public health recommendations

• 0-6 months: 40 mg
• 6-12 months: 50 mg
• 1-3 years: 15 mg
• 4-8 years: 25 mg
• 9-13 years: 45 mg
• 14-18 years, female: 65 mg
• 14-18 years, male: 75 mg
• 19+ years, female: 75 mg
• 19+ years, male: 90 mg
• Pregnant women, 14-18 years: 80 mg
• Pregnant women, 19+ years: 85 mg
• Lactating women, 14-18 years: 115 mg
• Lactating women, 19+ years: 120 mg

The 2000 DRI report also included a Tolerable Upper Intake Level (UL) for vitamin C of 2000 mg for adults. Although the report does not draw a distinction between dietary vitamin C and supplements, it would be hard to routinely go above this UL from food alone.

According to the DRI, smokers require extra vitamin C, and should add 35 mg to their daily RDA from the chart above. You’d find those 35 mg in a single serving of beet or mustard greens.

The Daily Value (DV) of vitamin C that you’ll see on food labels is 60 mg.

We adopted 75 milligrams per day—the DRI for adult women 19 years and older—as our WHF recommended daily intake level for vitamin C.

What events can indicate a need for more high-vitamin C foods?

• Poor wound healing
• Frequent colds or infections
• Lung-related problems

Excellent sources of vitamin C include: parsley, broccoli, bell pepper, strawberries, oranges, lemon juice, papaya, cauliflower, kale, mustard greens, and Brussels sprouts.

WHF rich in
vitamin C

FoodCals%Daily Value

Papaya119313.1%

Bell Peppers29195.8%

Strawberries46141.1%

Broccoli31135.2%

Pineapple83131.4%

Brussels Sprouts38124.6%

Kiwifruit45120%

Oranges62116.1%

Cantaloupe5497.8%

Kale3688.8%

For serving size for specific foods, see Nutrient Rating Chart below at the bottom of this page.

• Description

• Function

• Deficiency Symptoms

• Toxicity Symptoms

• Cooking, storage and processing

• Factors that affect function

• Nutrient interaction

• Health conditions

• Food Sources

• Public Health Recommendations

• References

Description

What is vitamin c?

Because of its widespread use as a dietary supplement, vitamin C may be more familiar to the general public than any other nutrient. Studies indicate that more than 40% of older individuals in the U.S. take vitamin C supplements; and in some regions of the country, almost 25% of all adults, regardless of age, take vitamin C. Outside of a multivitamin, vitamin C is also the most popular supplement among some groups of registered dietitians, and 80% of the dietitians who take vitamin C take more than 250 milligrams. Why is this nutrient so popular?

Vitamin C, also called ascorbic acid, is a water-soluble nutrient that is easily excreted from the body when not needed. It’s so critical to living creatures that almost all mammals can use their own cells to make it. Humans, gorillas, chimps, bats, guinea pigs and birds are some of the few animals that cannot make vitamin C inside of their own bodies.

Humans vary greatly in their vitamin C requirement. It’s natural for one person to need 10 times as much vitamin C as another person; and a person’s age and health status can dramatically change his or her need for vitamin C. The amount of vitamin C found in food varies as dramatically as our human requirement. In general, an unripe food is much lower in vitamin C than a ripe one, but provided that the food is ripe, the vitamin C content is higher when the food is younger at the time of harvest.

How it functions

What is the function of vitamin c?

Vitamin C serves a predominantly protective role in the body. As early as the 1700’s, vitamin C was referred to as the “antiscorbutic factor,” since it helped prevent the disease called scurvy. This disease was first discovered in British sailors, whose sea voyages left them far away from natural surroundings for long periods of time. Their body stores of vitamin C fell below 300 milligrams, and their gums and skin lost the protective effects of vitamin C. Recognizing limes as a good shipboard source of vitamin C, the British sailors became known as “limeys” for carrying large stores of limes aboard ship.

The protective role of vitamin C goes far beyond our skin and gums. Cardiovascular diseases, cancers, joint diseases and cataracts are all associated with vitamin C deficiency and can be partly prevented by optimal intake of vitamin C. Vitamin C achieves much of its protective effect by functioning as an antioxidant and preventing oxygen-based damage to our cells. Structures that contain fat (like the lipoprotein molecules that carry fat around our body) are particularly dependent on vitamin C for protection.

Deficiency symptoms

What are deficiency symptoms for vitamin c?

Full-blown symptoms of the vitamin C deficiency disease called scurvy—including bleeding gums and skin discoloration due to ruptured blood vessels—are rare in the U.S. Poor wound healing, however, is not rare, and can be a symptom of vitamin C deficiency. Weak immune function, including susceptibility to colds and other infections, can also be a telltale sign of vitamin C deficiency. Since the lining of our respiratory tract also depend heavily on vitamin C for protection, respiratory infection and other lung-related conditions can also be symptomatic of vitamin C deficiency.

Toxicity symptoms

What are toxicity symptoms for vitamin c?

There are very few research studies that document vitamin C toxicity at any level of supplementation, and there are no documented toxicity effects whatsoever for vitamin C in relation to food and diet. At high supplemental doses involving 5 or more grams of vitamin C, diarrhea can result from the fluid in the intestine becoming too concentrated (“osmotic diarrhea”).

Large supplemental doses of vitamin C can also increase levels of uric acid in the urine, because vitamin C can be broken down into uric acid. However, it is not clear that increased uric acid in the urine can increase a person’s risk of forming uric acid kidney stones.

Finally, vitamin C can increase a person’s absorption of iron from plant foods; and persons who have health problems related to excess free iron in their cells may want to consider avoiding high supplemental doses of vitamin C. It is important to remember that all of the above toxicity-related issues involve vitamin C in supplemental form, not as it naturally occurs in food.

In 2000, the National Academy of Sciences set a Tolerable Upper Intake Level (UL) for vitamin C at 2,000 milligrams (2 grams) for adults 19 years or older.

Factors that affect function

What factors might contribute to a deficiency of vitamin c?

Poor intake of vitamin C-rich vegetables and fruits is a common contributor to vitamin C deficiency. In the U.S., one third of all adults get less vitamin C from their diet than is recommended by the National Academy of Sciences, and 1 out of every 6 adults gets less than half the amount recommended. Smoking and exposure to second hand smoke also increase the risk of vitamin C deficiency.

The body’s immune and detoxification systems make special use of vitamin C, and overload in either of these systems can increase risk of deficiency. The immune system relies on a wide variety of mechanisms to help protect the body from infection, including white blood cells, complement proteins, and interferons; and vitamin C is especially important in the function of these immune components.

Vitamin C is also critical during the first phase of the body’s detoxification process. This process occurs in many types of tissue, but it is especially active in the liver. When the body is exposed to toxins, vitamin C is often required for the body to begin processing the toxins for elimination. Excessive toxic exposure is therefore a risk factor for vitamin C deficiency.

Nutrient interactions

How do other nutrients interact with vitamin c?

Vitamin C has significant interactions with several key minerals in the body.

Supplemental intake of vitamin C at gram-level doses can interfere with copper metabolism. Conversely, vitamin C can significantly enhance iron uptake and metabolism, even at food-level amounts.

Vitamin C also has important interactions with other vitamins. Excessive intake of vitamin A, for example, is less toxic to the body when vitamin C is readily available. Vitamin C is involved in the regeneration of vitamin E, and these two vitamins appear to work together in their antioxidant effect.

Health conditions

What health conditions require special emphasis on vitamin c?

Most forms of cardiovascular disease, joint disease, cancer, eye disease, thyroid disease, liver disease, and lung disease require special emphasis on vitamin C intake. The process of aging itself requires special attention to vitamin C. In addition to these broader categories, several specific health conditions also require special emphasis on vitamin C. These specific health conditions include:

• Acne
• Alcoholism
• Alzheimer’s disease
• Asthma
• Autism
• Depression
• Diabetes
• Irritable bowel disease
• Parkinson’s disease

Food sources

What foods provide vitamin c?

Excellent food sources of vitamin C include broccoli, bell peppers, parsley, Brussels sprouts, cauliflower, lemon juice, strawberries, mustard greens, kiwifruit, papaya, kale, cabbage, romaine lettuce, turnip greens, oranges, cantaloupe, summer squash, grapefruit, pineapple, chard, tomatoes, collard greens, raspberries, spinach, green beans, fennel, cranberries, asparagus, watermelon, and winter squash.

Drug-nutrient interactions

What medications affect vitamin c?

Categories of drugs that can diminish the body’s supply of vitamin C include oral contraceptives (birth control pills), NSAIDs (non-steroidal anti-inflammatory drugs including aspirin), corticosteroids (like cortisone), sulfa drugs (often used as antibiotics or in cancer treatment), and barbituates.

Form in dietary supplements

What forms of vitamin C are found in dietary supplements?

Dietary supplements typically contain vitamin C in the form of ascorbic acid. Because vitamin C is better absorbed in the presence of flavonoids, many supplement manufacturers also add flavonoids to their formulas.

Buffered versions of vitamin C are also commonly available. These buffered forms usually combine vitamin C with minerals like calcium, magnesium, or potassium. Buffered vitamin C may be helpful for individuals who have stomach sensitivity, or who are taking higher doses of the supplement.

Also widely available is a metabolite complex form of vitamin C, sold commercially under the trade name Ester-C(TM), in which ascorbic acid is combined with several of its naturally occurring metabolites including dehydroascorbate, threonate, and aldonic acids.

Related Articles

• Are sprouts good for me?
• Can salads be a good source of calcium?
• Can you get too many antioxidants?
• Can you tell me about oxalates, including the foods that contain them and how are they related to nutrition and health?
• Can you tell me more about green tea?
• Can you tell me more about pasteurization?
• Do dried fruits contain more nutritional value than fresh fruits?
• Do I need to eat dairy products in order to prevent osteoporosis?
• Does chlorophyll provide health benefits?
• Does Healthy Eating require cooking on a regular basis?
• High-Temperature Cooking & The World's Healthiest Foods
• How can my diet help protect me from sunburn?
• How do cooking temperatures affect vegetable nutrients?
• How do pickles compare to raw cucumbers in terms of nutrition?
• How does cooking affect the nutrients in green beans?
• How Does Cutting, Slicing, and Chopping Affect Fresh Vegetables?
• How does fruit juice compare to whole fruit?
• How Much of a Problem is Iron in a Vegetarian Diet?
• How popular are organic foods and why have they become a food trend?
• How to prepare broccoli to retain its nutritional value.
• How to Store Cabbage to Preserve Quality
• Is it true that flax seeds are not a good source of omega 3s for some people?
• Open Letter to President Barack Obama
• Organic foods higher in vitamins, minerals, phytonutrients, lower in nitrates
• What are purines and how are they related to food and health?
• What are some of the best ways to cook Swiss chard?
• What Do You Think About Microwave Cooking?
• What is the best way to cook onions so as to maximize the benefit of their sulfur-containing phytonutrients?
• What Is the best way to roast nuts and seeds?
• What is The Healthiest Way of Eating?
• What is the Special Nutritional Power found in Phytonutrients?
• Which foods are classified as "nightshades," and why are adverse reactions sometimes associated with these foods?
• Why Organic Foods are Better for Health
• Why should I include fish in my diet?
• World's Healthiest Foods Way of Eating

References

1. Bruno RS, Ramakrishnan R, Montine TJ, et al. Alpha-tocopherol disappearance is faster in cigarette smokers and is inversely related to their ascorbic acid levels. Am J Clin Nutr. 2005;81:95-103. https://doi.org/10.1158/1940-6207.capr-11-0002
2. Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999;69:1086-107. https://doi.org/10.1093/ajcn/69.6.1086
3. Felicetti E, Mattheis JP. Quantification and histochemical localization of ascorbic acid in 'Delicious,' 'Golden Delicious,' and 'Fuji' apple fruit during on-tree development and cold storage. Postharvest Biol Tech 2010;56:56-63. https://doi.org/10.1016/j.postharvbio.2009.12.002
4. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press; 2000;284-324.
5. Frei B, Birlouez-Aragon I, Lykkesfeldt J. Authors' perspective: What is the optimal intake of vitamin C in humans? Crit Rev Food Sci Nutr 2012;52:815-29. https://doi.org/10.1186/s13643-020-01554-9
6. Korus A, Lisiewska Z. Effect of preliminary processing and method of preservation on the content of selected antioxidative compounds in kale (Brassica oleracea L. var. acephala) leaves. Food Chem 2011;129:149-54. https://doi.org/10.1016/j.foodchem.2011.04.048
7. Pellegrini N, Chiavaro E, Gardana C, et al. Effect of different cooking methods on color, phytochemical concentration, and antioxidant capacity of raw and frozen Brassica vegetables. J Agric Food Chem 2010;58:4310-21. https://doi.org/10.1021/jf904306r
8. Raseetha S, Leong SY, Burritt DJ, et al. Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing. Food Chem 2013;138:1360-9. https://doi.org/10.1016/j.foodchem.2012.09.126
9. Sanhueza C, Ryan L, Foxcroft DR. Diet and the risk of unipolar depression in adults: systematic review of cohort studies. J Hum Nutr Diet 2013;26:56-70. https://doi.org/10.1111/j.1365-277x.2012.01283.x
10. Zhan L, Hu J, Ai Z, et al. Light exposure during storage preserving soluble sugar and L-ascorbic acid content of minimally processed romaine lettuce (Lactuca sativa L. var. longifolia). Food Chem 2013;136:273-8. https://doi.org/10.3390/molecules24193440
11. Bruno RS, Ramakrishnan R, Montine TJ, et al. Alpha-tocopherol disappearance is faster in cigarette smokers and is inversely related to their levels. Am J Clin Nutr. 2005;81:95-103. https://doi.org/10.1038/s41573-021-00233-1
12. Felicetti E, Mattheis JP. Quantification and histochemical localization of ascorbic acid in ‘Delicious,’ ‘Golden Delicious,’ and ‘Fuji’ apple fruit during on-tree development and cold storage. Postharvest Biol Tech 2010;56:56-63. https://doi.org/10.1016/j.postharvbio.2009.12.002
13. Frei B, Birlouez-Aragon I, Lykkesfeldt J. Authors’ perspective: What is the optimal intake of vitamin C in humans? Crit Rev Food Sci Nutr 2012;52:815-29. https://doi.org/10.1186/s13643-020-01554-9
14. Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999;69(6):1086-1107. 1999. https://doi.org/10.1093/ajcn/69.6.1086
15. Englard S, Seifter S. The biological functions of ascorbic acid. Ann Rev Nutr 1986;6:365-406. 1986. https://doi.org/10.1093/jnci/83.8.547
16. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995. 1995.
17. Kurl S, Tuomainen TP, Laukkanen JA et al. Plasma vitamin C modifies the association between hypertension and risk of stroke. Stroke 2002 Jun;33(6):1568-73. 2002. https://doi.org/10.1161/01.str.0000017220.78722.d7
18. Levine M. New concepts in biology and biochemistry of ascorbic acid. N Engl J Med 1986;314:892-902. 1986. https://doi.org/10.1056/nejm198604033141407
19. Levine M, Cantilena CC, Dhariwal KR. Determination of optimal vitamin C requirements in humans. Am J Clin Nutr 1995;62(suppl):1347S-1356S. 1995. https://doi.org/10.1093/ajcn/62.6.1347s
20. Linder MC. Food quality and its determinants from field to table - growing food, its storage and preparation, Chapter 10. In: M Linder (ed) Nutritional biochemistry and Metabolism with clinical applications, Elsevier, New York, London, 1991;239-254. 1991. https://doi.org/10.1016/j.foodhyd.2011.02.007
21. Medeiros DM, Bock MA, Raab C, et al. Vitamin and mineral supplementation practices of adults in seven western states. J Am Diet Assoc 1989;89(3):383-386. 1989. https://doi.org/10.1016/s0002-8223(21)02128-3
22. Reaven PD, Witztum JL. Oxidized low density lipoproteins in atherogenesis: role of dietary modification. Ann Rev Nutr 1996;16:51-71. 1996. https://doi.org/10.1146/annurev.nu.16.070196.000411
23. Subar A, Block G. Use of vitamin and mineral supplements. Am J Epidem 1990;132:1901-1011. 1990. https://doi.org/10.1007/bf03405270
24. Worthington-Roberts B, Breskin M. Supplementation patterns of Washington State dietitians. J Am Diet Assoc 1984;84(7):795-800. 1984. https://doi.org/10.1016/s0002-8223(21)08247-x
25. Carr AC, Frei B. Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999;69(6):1086-1107 1999. https://doi.org/10.1093/ajcn/69.6.1086
26. Englard S, Seifter S. The biological functions of ascorbic acid. Ann Rev Nutr 1986;6:365-406 1986. https://doi.org/10.1093/jnci/83.8.547
27. Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995 1995.
28. Kurl S, Tuomainen TP, Laukkanen JA et al. Plasma vitamin C modifies the association between hypertension and risk of stroke. Stroke 2002 Jun;33(6):1568-73 2002. https://doi.org/10.1161/01.str.0000017220.78722.d7
29. Levine M. New concepts in biology and biochemistry of ascorbic acid. N Engl J Med 1986;314:892-902 1986. https://doi.org/10.1056/nejm198604033141407
30. Levine M, Cantilena CC, Dhariwal KR. Determination of optimal vitamin C requirements in humans. Am J Clin Nutr 1995;62(suppl):1347S-1356S 1995. https://doi.org/10.1093/ajcn/62.6.1347s
31. Linder MC. Food quality and its determinants from field to table - growing food, its storage and preparation, Chapter 10. In: M Linder (ed) Nutritional biochemistry and Metabolism with clinical applications, Elsevier, New York, London, 1991;239-254 1991. https://doi.org/10.1016/j.foodhyd.2011.02.007
32. Medeiros DM, Bock MA, Raab C, et al. Vitamin and mineral supplementation practices of adults in seven western states. J Am Diet Assoc 1989;89(3):383-386 1989. https://doi.org/10.1016/s0002-8223(21)02128-3
33. Reaven PD, Witztum JL. Oxidized low density lipoproteins in atherogenesis: role of dietary modification. Ann Rev Nutr 1996;16:51-71 1996. https://doi.org/10.1146/annurev.nu.16.070196.000411
34. Subar A, Block G. Use of vitamin and mineral supplements. Am J Epidem 1990;132:1901-1011 1990. https://doi.org/10.1007/bf03405270
35. Worthington-Roberts B, Breskin M. Supplementation patterns of Washington State dietitians. J Am Diet Assoc 1984;84(7):795-800 1984. https://doi.org/10.1016/s0002-8223(21)08247-x