Is Too Much Vitamin C Harmful to Your Health?

Too Much Vitamin C

Vitamin C is abundant in raw fruits and vegetables and is critical for healthy functioning. You need vitamin C to build healthy collagen, a structural protein that gives your skin and joints support and resistance to aging. Plus, vitamin C is an antioxidant vitamin that helps fight oxidative stress, free radical activity that damages cells and tissues and contributes to aging. As an antioxidant, it also helps recycle other antioxidants, like vitamin E. In addition, you need vitamin C for wound healing and for a healthy immune system. Although uncommon, a severe deficiency of vitamin C can lead to scurvy, a life-threatening condition where the connective tissue in the body breaks down.

How to Get Vitamin C

As mentioned, the best source of vitamin C is fruits and vegetables, although cooking destroys a significant quantity of vitamin C in foods. If you eat a diet rich in fruits and vegetables, including some raw produce, you get more than enough vitamin C in your diet since you only need 65 to 90 milligrams of vitamin C daily, a quantity that most people get unless they’re eating a diet that excludes fruits and vegetables. . A medium orange has around 60 milligrams, and a serving of papaya has 180 milligrams of vitamin C. A sweet pepper contains between 90 milligrams and 150 milligrams of vitamin C. Some packaged foods are also fortified with vitamin C.

People who take supplemental vitamin C often take several times the recommended daily intake because they believe that getting more may have added health benefits, yet there isn’t sound evidence to support this idea, although it is important to get the recommended daily intake of vitamin C.

Is it possible to get too much vitamin C through diet or supplements? You don’t have to worry about overdosing on vitamin C from food, but if you take high doses of vitamin C in supplement form, you could experience some side effects and, possibly, incur some risks. That’s why it’s a good idea to get vitamins and minerals through diet when possible.

The Risks of Taking High Doses of Vitamin C

Vitamin C is a water-soluble vitamin that enters your urine when you take more than your body can use. Therefore, the risk of serious toxicity is lower than with fat-soluble vitamins, like vitamins A, E, D, and K. However, people who take high-dose vitamin C supplements can experience nausea, vomiting, diarrhea, headache, or abdominal cramping.

Another problem with taking vitamin C supplements is the absorption factor. You absorb vitamin C from food and supplements up to 180 milligrams per day. So, your body can only absorb so much at one time. The rest may not be available to your body, and then there are concerns about side effects. According to Mayo Clinic, you shouldn’t take avoid 2,000 milligrams of vitamin C daily to avoid side effects and risks.

What are the risks of taking too much vitamin C? If you have a history of calcium oxalate kidney stones, the most common kind of kidney stone, talk to your physician before taking a vitamin C supplement.  When your body breaks down vitamin C, it produces oxalates that can bind to calcium and cause kidney stones. However, some studies question whether this is truly a risk. One study found a higher risk only in men, but not in women, and it’s not clear how much of a risk vitamin C poses for kidney stones.

Another concern is that vitamin C may have pro-oxidant activity if you consume large quantities in supplement form. Pro-oxidants have the opposite effect of an antioxidant. Rather than protect against oxidative stress, they cause free radical damage to cells and tissues and may increase the risk of cancer. Other micronutrients can also have paradoxical effects, depending upon the dose.  For example, iron is an antioxidant at lower levels but has pro-oxidant activity at higher levels in the body. That’s exactly the kind of tissue damage that antioxidants protect against! So too much vitamin C can have the opposite effect. It’s an example of how something beneficial can be harmful if you get too much.

Vitamin C also boosts the absorption of iron. That could be a problem for people who have a hereditary condition called hemochromatosis where their liver stores excess iron. Plus, vitamin C can interact with some medications, including chemotherapy medications, estrogen replacement therapy, birth control pills, statins, and blood thinners. That’s why it’s important to let your physician know if you take supplements.

You Might Need More Vitamin C Under Certain Circumstances

The recommended daily allowance (RDA) for vitamin C is 90 milligrams for men and 75 milligrams for women. Some people, however, may need additional vitamin C. For example, smokers need 35 milligrams of vitamin C above the RDA since smoking increases oxidative stress. There are certain conditions that getting more vitamin C may slow or prevent. For example, taking a vitamin C supplement may prevent or delay the progression of age-related macular degeneration (AMD), a common cause of age-related vision loss. Also, you might need supplemental vitamin C if you have an intestinal condition that affects your ability to absorb this vitamin. However, most healthy people can get enough vitamin C through diet as long as they don’t eat a diet that restricts vitamin C-rich foods.

The Bottom Line

Getting too much vitamin C carries a risk of side effects, and supplemental vitamin C can interact with some medications. However, you should be aware of how much vitamin C you take in and be sure you’re getting enough fruits and vegetables in your diet. A study found that about one-third of the population has sub-clinical vitamin C deficiency. So, getting enough should be a concern but don’t go overboard and take a high-dose supplement without talking to your physician first. Why not enjoy a rich array of fruits and vegetables to meet your body’s vitamin C needs? You’ll also get the benefits of the other vitamins, minerals, and antioxidants in these foods.



  • org. “Is it possible to take too much vitamin C?”
  • National Institutes of Health. “Vitamin C”
  • Am J Kidney Dis. 2016 Mar; 67(3): 400–407.Published online 2015 Oct 14. doi: 10.1053/j.ajkd.2015.09.005.
  • Nutr Clin Care. Mar-Apr 2002;5(2):66-74. doi: 10.1046/j.1523-5408.2002.00005.x.


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