Also called ascorbic acid, vitamin C is one of the many water-soluble nutrients found naturally in fruits and vegetables. Many people also take supplements to ensure they’re getting enough of it. This has raised concerns over the likelihood of an accidental overdose.

Too much vitamin C can cause undesirable effects. However, a severe overdose is rare and unlikely. The key is to learn how much vitamin C you really need.

What Does Vitamin C Do?

Vitamin C is a type of antioxidant. It helps protect the body from free radicals that damage and destroy otherwise healthy cells. In this respect, getting enough of the nutrient is just one way you can support your body’s natural defenses against illness. This is how it gained its reputation as a virus-fighting vitamin.

It also helps increase iron absorption, which is essential for growth and overall body functions. Not having enough vitamin C can lead to a potentially deadly condition known as scurvy.

Oranges and orange juices are perhaps the best-known sources of vitamin C, but other items in the produce aisle are chock-full, including:

• bell peppers
• broccoli
• cantaloupe
• grapefruit
• kiwi
• potatoes
• strawberries
• tomatoes

You probably don’t need a vitamin C supplement if you eat a lot of fruits and vegetables. In fact, just one serving of any of the above foods likely will get you to your daily quota.

How Much Is Too Much?

According to the National Institutes of Health, the average adult woman requires 70mg of vitamin C a day. The average man requires 90mg. Recommended amounts are higher for pregnant and nursing women.

It’s important to discuss your individual nutritional needs with your doctor. The maximum recommended amount, or upper limit, is 2,000mg per day for all adults.

Taking more than the upper limit for vitamin C isn’t life-threatening, but you may experience side effects like:

• abdominal pain
• cramps
• diarrhea
• headaches
• nausea (and possible vomiting)
• sleeping problems

People with hemochromatosis are in danger of a vitamin C overdose. This condition causes your body to store excessive amounts of iron, which is exacerbated by taking too much vitamin C. This condition can lead to body tissue damage.

Vitamin C supplements may also interact with certain medications. This is especially true of medications for heart disease and cancer. Be sure to check with your doctor before taking a supplement.

Other Ways to Boost Your Immune System

Despite what supplement makers have led you to believe, there is no scientific evidence that vitamin C directly prevents colds and flu viruses. In fact, the National Center for Complementary and Alternative Medicine says that taking these costly supplements only slightly minimizes the duration of a cold. Furthermore, taking vitamin C after getting sick doesn’t help at all.

You’re better off saving your money and making sure you get enough vitamin C in your daily diet instead.

As with other preventive health measures, the best way to ward off cold and flu viruses is to take care of yourself. You can accomplish this by:

• getting adequate sleep every night
• exercising regularly
• eating nutritious foods
• refraining from excess caffeine and alcohol

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