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How much Vitamin C is too much? Symptoms & Side effects

Vitamin C is an essential micronutrient that is necessary for many functions throughout the body.

There are several benefits of Vitamin C. It helps to build immunity (1), rid the body of free radicals (2), produce collagen to improve skin health (3), and more. It also assists in the growth of tendons, ligaments, and blood vessels, heal wounds from scar tissue, and repair bone, teeth, and cartilage health. It even plays a role in proper brain function (4).

It is possible to take too much vitamin C, so be aware that taking too much vitamin C is not necessarily a good thing. Too much of an essential vitamin can do just as much harm as good.

Immunity is a crucial component with vitamin C, also known as ascorbic acid (5, 6). Free radicals can build up in the body if you eat too many refined foods, not enough vitamin C-rich foods, or not enough of other nutrient-dense foods (7, 8).

Vitamin C is one of the most important antioxidants that the body needs to function well. The reason is it so vital for immunity is it helps to support many cellular roles throughout the body (9).

It helps with skin health because it plays a role in converting collagen in the body (10, 11). The skin is the largest organ in the body. There are two layers in the skin, the epidermal and the inner dermal layer. Skin naturally contains high amounts of vitamin C to protect you against UV photodamage, stimulates collagen creation, and supports skin elasticity (12, 13).

Too much Vitamin C

That is often why many skincare products contain vitamin C to promote fewer wrinkles, elasticity, and more. But there is a lack of evidence to support those claims fully. Many foods have abundant amounts of vitamin C, too. But vitamin C can help to prevent sunburn, as it protects the skin from UV damage (14). It can never replace sunscreen in that regard, but it can help prevent it in combination with sunscreen (15).

Do you think you are getting too much vitamin C in your diet through food or supplementation? Learn more about how much vitamin C is too much, symptoms, side effects, and how much you should be taking below.

How much Vitamin C is too much?

You can get too much vitamin C, mostly through supplementation (16). It is rare and difficult to get too much vitamin C from foods rich in this nutrient alone.

 

Make sure to not go over the maximum dosage of 2,000 mg of vitamin C per day (17, 18). Although vitamin C is a water-soluble vitamin, it can stay in the body for weeks at a time (19). If you take too much vitamin C, it can be further absorbed in the kidneys, making it hard to pass through urine (20).

If the amount is only slightly over the maximum, it can overwhelm your body, and the excess can pass through the urine within a few hours (21). The main takeaway with too much vitamin C is if you are taking the recommended amount that is under the daily recommended upper limit, you should be fine with absorption rates. If you exceed the upper limit regularly, that can cause issues downstream later that can affect the kidneys, digestive system, and more (22, 23).

An easy way to remember to get enough vitamin C is to get enough of this essential micronutrient in your daily diet. Supplementing with vitamin C is not necessary for everyone to do daily. It can come in handy if you are feeling ill, or if you want to prevent illness, but never exceed more than 2,000 mg per day. That will help you avoid any downstream issues from happening down the road.

Try to eat a diet high in nutrient-dense foods rich in vitamin C and stay clear of foods high in processed and refined foods. It can be easier to miss out on vitamin C-rich foods if you skip them in your regular diet.

When you get too much vitamin C from supplementation, symptoms can set in, and you will be able to tell if you are getting too much. Common symptoms of too much vitamin C include diarrhea, stomach upset, and more (24, 25). Read on to learn more about more common symptoms of getting too much vitamin C.

Symptoms of too much Vitamin C (Overdose)

If you take more than 2,000 mg of vitamin C regularly, you may experience symptoms of overdose. Some of the most common symptoms of overdose include:

  • Diarrhea
  • Nausea
  • Vomiting
  • Stomach upset
  • Heartburn
  • Headache
  • Sleep issues such as insomnia
  • Stomach cramps

These symptoms are most commonly the consequence of mega doses of vitamin C supplementation, not vitamin C from foods. It is hard to take too much vitamin C from foods because the body is much more readily available to handle the absorption of vitamin C through food.

They are at a lower dosage and in different forms. Vitamin C comes in two forms via supplements. Typically, you can either find vitamin C in the ascorbic acid form of buffered vitamin C. Buffered vitamin C may be a better option if you experience stomach upset from a low amount of ascorbic acid (26). Always be sure to talk to your doctor if you are unsure about what you need for optimal health.

As you can see, many of these symptoms are severe and are often rare. It is possible to get adequate levels of vitamin C daily from your diet alone.

There are many foods high in vitamin C, and they do not only include citrus fruits. Although citrus fruits contain vitamin C, many other foods have more of this vital micronutrient.

These other foods high in vitamin C include red bell peppers, broccoli, strawberries, sweet and white potatoes, spinach and other leafy greens, tomatoes, squash, cabbage, cauliflower, and more.

Remember to eat a healthy, balanced diet full of fruits, vegetables, healthy carbohydrates, and more to make sure you are getting the proper amount of vitamin C each day.

Unsure where to start your new healthy diet? Speak to a health coach, nutritionist, or dietician so they can help you get started seamlessly and without stepping back into unhealthy patterns.

Side Effects

Along with the symptoms above, there are other aspects of your health that too much vitamin C can affect.

Remember that your body cannot produce vitamin C naturally, so it is essential to get it from a healthy diet and possibly supplementation for some.

The most common side effects include stomach upset, either through cramping, vomiting, or digestive distress (27, 28). Further problems can arise with digestive issues as well.

Digestive distress can occur with too much vitamin C, but this is only in regards to supplementation. That is not often an issue with food alone.

Acid reflux is another digestive disorder that can occur with too much vitamin C (29). Although more evidence is necessary to support this, it is a common culprit that can come up. Acid reflux starts from an imbalance in stomach acid in the gut (30). It is crucial to get to the root cause of acid reflux and find out if too much vitamin C is the issue or if it is another underlying health issue.

Another side effect of too much vitamin C is getting too much iron. Even though it sounds unrelated, vitamin C boosts the absorption of iron in the body (31, 32). Iron is a fat-soluble nutrient, unlike vitamin C, and it cannot pass through urine.

Therefore, too much iron must get excreted through blood work. Some may suffer from a build-up of too much iron in the body, known as hemochromatosis (33), and that can cause an issue with vitamin C supplementation. Those with hemochromatosis should be careful and try to avoid vitamin C supplements as it can boost iron in the body as well. Speak with your doctor if you have this condition to make sure.

Even beyond hemochromatosis, it is possible to get too much vitamin C, leading to iron overload in the body. Over time, this can cause issues to the pancreas, liver, heart, thyroid, and even the nervous system overall (34, 35).

If you do not have a condition where your body produces too much iron, and you are not taking iron supplements, you will likely be OK with the amounts.

Too much vitamin C can also cause kidney stones, although it is rare. The oxalate that passes through the body from vitamin C can, in some situations, crystalize into kidney stones. One study shows that this can occur from taking regular high doses of 1,000 mg of vitamin C for several consecutive days (36).

How much vitamin C should I take?

You never want to exceed the upper limit of more than 2,000 mg of vitamin C per day. But the recommended daily requirement for vitamin C is 65 to 90 mg a day for adults (37).

If you do not have high levels of vitamin C in your body, it will likely stay in the body longer than someone who already has adequate levels. That is because vitamin C is water-soluble, and it can pass through the urinary tract.

If you want to boost your vitamin C levels, try to take smaller doses throughout the day, instead of 1,000 mg at once. Vitamin C is fully absorbed when it is under 200 mg. It still gets absorbed in 500 mg, but only at a fraction of the amount.

To boost your vitamin C faster, space out the doses throughout the day. Remember not to exceed the upper limit of 2,000 mg per day.

Conclusion

Vitamin C is a necessary water-soluble micronutrient that everyone needs to consume daily. There are a plethora of foods rich in vitamin C to make consumption easy.

Side effects and symptoms of vitamin C overdose are rare, and they can only happen if you are consuming mega dosages of supplements.

Remember to eat plenty of vegetables, fruits, and other foods high in vitamin C to meet your daily recommended requirement. That will help to ensure you are getting enough without having to worry about supplementation as much.

Cut back on the amount of vitamin C you are taking if you experience any of the symptoms or side effects. If they do not resolve on their own, be sure to speak with your healthcare professional.

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Evidence Based

This article is based on scientific evidence, and written, fact-checked & medically reviewed by health experts.

Throughout this article, you'll find scientific references (clickable links to highly trusted peer-reviewed scientific papers, links denoted by the numbers in the parentheses (1, 2, 3)).