What Is Vitamin C?
Vitamin C, also called L-ascorbic acid, is a water-soluble vitamin that is an essential part of your diet. Although some animals can produce their own vitamin C, humans have to get it from other sources. Research suggests that eating foods rich in vitamin C is essential to staying healthy.
You can get plenty of vitamin C from fresh fruits and vegetables, but it's also available as a dietary supplement.
Importance of Vitamin C
Vitamin C helps your body produce compounds (collagen, L-carnitine, and neurotransmitters) that are important for your nerves, heart, brain, muscles, and energy production.
Vitamin C is an antioxidant, a substance that protects your cells against free radicals. These are unstable molecules that can damage cells. This cell damage may play a role in health problems like Alzheimer's disease, cancer, and heart disease.
Vitamin C also helps your body metabolize protein and absorb iron.
Some specific health benefits of vitamin C are:
Wound healing: You need vitamin C to help your body make collagen, which is a protein that's essential for your connective tissues and for wound healing.
Immune function: Vitamin C also helps your body's immune system fight disease and infections, by helping trigger it to make more white blood cells.
Maintenance of bones, teeth, and cartilage: Vitamin C helps your bones, teeth, and cartilage (the rubbery material that covers the ends of bones) stay healthy, too. It might also reduce your risk of cartilage loss, especially if you have osteoarthritis.
Vitamin C Deficiency
A serious lack of vitamin C is relatively rare. If you smoke, have a very limited diet, or have certain medical conditions like cancer or kidney disease, you could be at a higher risk of deficiency. Serious deficiency can cause a disease called scurvy, though it's very rare in the U.S. Symptoms of scurvy include:
- Fatigue
- Crankiness and sadness
- Severe joint or leg pain
- Swollen, bleeding gums
- Red or blue spots on your skin
- Your skin bruises easily
Vitamin C in Foods
Cantaloupe
Cantaloupe is a rich source of vitamin C, with 202.6 milligrams of the vitamin in a medium-sized melon, and 25.3 milligrams in one slice.
Citrus fruits
Raw citrus fruits are very high in vitamin C. One medium orange provides 70 milligrams of vitamin C, while one grapefruit has about 96 milligrams. Citrus fruit juices have even more vitamin C, with a cup of orange juice providing around 71 milligrams. Just watch out for the added sugars.
Broccoli
Surprisingly, a cup of broccoli contains as much vitamin C as an orange. Broccoli is a good source of other vitamins and minerals, such as:
- Calcium
- Iron
- Phosphorous
- Potassium
- Zinc
- Thiamin
- Riboflavin
- Niacin
- Folate
Red cabbage
Red cabbage, also called purple cabbage, is high in vitamin C and low in calories. A half-cup has only 14 calories but almost 30% of the recommended daily value of vitamin C.
Kiwi
Depending on its size, one kiwi can pack as much as 56 milligrams of vitamin C. That's more than half your recommended dietary allowance (RDA).
Bell peppers
Bell peppers have more nutrients than other peppers because they're left on the vine longer to ripen. One cup of chopped red bell peppers has a whopping 191 milligrams of vitamin C, while a cup of chopped green bell peppers has 120 milligrams.
Kale
You'll get tons of vitamin C from kale whether you eat it raw or cooked. One cup of raw kale has about 19.2 milligrams, while a cup of cooked kale has 21 milligrams.
Brussels sprouts
Just a half cup has 49 milligrams, more than half of your RDA.
Strawberries
One cup of strawberries has 97.6 milligrams of vitamin C, plus lots of other beneficial antioxidants.
Mustard greens
If you love greens, give mustard greens a try. They're loaded with nutrients, including 117 milligrams of vitamin C in a 1-cup serving.
Chili peppers
Green and red chili peppers both have plenty of vitamin C, about 109 milligrams and 65 milligrams, respectively.
Benefits of Vitamin C
Your body needs vitamin C to do everything from making blood vessels and cartilage to building muscles and bones. Vitamin C also helps your body heal when you're sick, injured, or recovering from things like surgery.
But vitamin C also has other health benefits. It may help with:
Colds. There's no cure for the common cold, and that includes vitamin C. It won't prevent a cold either, no matter how much you take. But research shows it might shorten your cold by a day or so, and it might make your symptoms a little milder.
Cancer prevention. If you get a lot of vitamin C from fruits and vegetables, you could be at a lower risk for some cancers, including lung, breast, and colon cancer. Vitamin C supplements don’t seem to offer the same protection.
Age-related macular degeneration (AMD) and cataracts. Vitamin C hasn't been shown to lower your chances of getting AMD, but researchers think that when it's combined with other nutrients, vitamin C might slow down how fast AMD develops. Some studies suggest that getting more vitamin C from foods can lower your odds of having cataracts. But there needs to be more research to know for sure and to find out if vitamin C supplements can affect your risk of cataracts.
How Much Vitamin C Per Day?
How much vitamin C you need depends your age and sex. Adults 19 and older need 75-90 milligrams of vitamin C a day, but children need less. If you eat the right foods, you should easily get enough from your regular diet.
The recommended dietary allowance of vitamin C includes how much you get from both food and any supplements you take.
- Birth to 6 months: 40 milligrams
- Infants 7-12 months: 50 milligrams
- Children 1-3 years: 15 milligrams
- Children 4-8 years: 25 milligrams
- Children 9-13 years: 45 milligrams
- Teens 14-18 years (boys): 75 milligrams
- Teens 14-18 years (girls): 65 milligrams
- Adults (men): 90 milligrams
- Adults (women): 75 milligrams
- Pregnant teens: 80 milligrams
- Pregnant adults: 85 milligrams
- Breastfeeding teens: 115 milligrams
- Breastfeeding adults: 120 milligrams
Smokers need 35 milligrams more vitamin C per day than nonsmokers.
The daily upper limits for vitamin C are the most you can safely have in a day from food and supplements. Don't take more unless your doctor tells you to.
- Birth to 12 months: Not established
- Children 1-3 years: 400 milligrams
- Children 4-8 years: 650 milligrams
- Children 9-13 years: 1,200 milligrams
- Teens 14-18 years: 1,800 milligrams
- Adults: 2,000 milligrams
Vitamin C Side Effects
Vitamin C is safe. But if you take too much in supplements, it can cause an upset stomach, heartburn, cramps, or a headache. High doses of vitamin C can cause health problems like kidney stones and severe diarrhea.
Vitamin C supplements can interact with medicines you take, including fluphenazine (Prolixin), indinavir (Crixivan), and warfarin (Coumadin), as well as those for cancer treatments. So talk to your doctor before you take vitamin C supplements.
If you're pregnant or have gout, liver disease, kidney disease, or another chronic disease, talk to your doctor before taking high doses of vitamin C.
