Is too Much Vitamin C Harmful? Facts and Myths
Suppose you grew up on a breakfast table with orange juice or grapefruit as your staple food. In that case, you know the importance of vitamin C. Water-soluble vitamin C, also known as ascorbic acid, keeps cells healthy and is involved in the growth and replacement of tissues throughout the body.
You also need Vitamin C, which helps keep the skin plump, absorb iron, heal wounds, and build the most important scar tissue. It also helps keep bones, teeth, cartilage, and blood vessels in good shape. (1)
It is not stored in the body as a water-soluble vitamin and is excreted excessively. So, the good news is that its toxicity is so low that even high doses are not associated with severe or fatal consequences. (2) However, many supplements contain so many vitamins that they can have unwanted side effects in some cases. This article examines the general safety of vitamin C, whether overdose is possible, and the potential side effects of high doses.
Vitamin C is water-soluble; unlike fat-soluble vitamins, water-soluble vitamins are not stored in the body. Instead, the vitamin C you consume is carried through your body fluids to your tissues, and the excess is excreted in the urine. Your body does not store or produce vitamin C, so eating daily foods rich in vitamin C is important. (3) However, supplementing with large amounts of vitamin C can cause side effects such as indigestion and kidney stones. This is because overloading the body with above average amounts of this vitamin can cause it to accumulate and cause symptoms of overdose. (4)
It is necessary to note that most people do not need to take vitamin C supplements, as eating fresh foods, fruits, and vegetables is easy enough to consume.
Signs of Vitamin C Overdose
It is usually safe to eat meals high in vitamin C frequently. Frequent intake of foods high in vitamin C does not cause any health problems. However, an overdose of vitamin C through dietary supplements can have side effects.
For adults, the recommended dietary reference intake for a reliable source of vitamin C is 90 milligrams (mg) for men and 75 mg for women. Adults who take more than 2,000 mg of vitamin C per day may experience side effects.
Mild dyspepsia can occur if people consume more than the recommended amount of vitamin C. These can occur when vitamin C, which is not absorbed by the body, stimulates the gastrointestinal tract. (5)
The common side effects of having too much vitamin C are:
- Diarrhea
- Nausea
- Gastric spasm
- Flatulence
General abdominal discomfort
The body does not get all the vitamin C it receives from supplements. For example, – if a person takes 30-180 mg of vitamin C daily, the body absorbs about 70-90% of this vitamin. (6)
-When a person consumes more than 1 gram (g) of vitamin C daily, the body absorbs less than 50% of the vitamins, reducing the risk of adverse side effects. The extras leave urine on the body.
Too much vitamin C can cause indigestion
The most common side effect of high vitamin C intake is indigestion. These side effects result from the intake of vitamins in dietary supplements, not from the input of foods containing vitamin C. Taking more than 2,000 mg at a time is most likely to cause digestive discomfort. Therefore, a daily upper limit of 2,000 mg has been set. (7) (8)
The most common gastrointestinal symptoms associated with an overdose of vitamin C are diarrhea and nausea. (9)
Overdose has also been reported to cause acid reflux, but this is not supported by evidence. If you have digestive problems due to an overdose of vitamin C, reduce the dose of the supplement or do not use any vitamin C supplements at all. (10)
Vitamin C can cause iron overload
Vitamin C is recognized to improve iron absorption. Can be bound to non-heme iron contained in vegetable foods. Non-heme iron is not absorbed as efficiently as heme iron, which is found in animal foods. (11)
Vitamin C binds to non-heme iron, making it easier for the body to absorb. This is an important feature, especially for those who get most of the iron from vegetable foods. (12)
A study of adults found that taking 100 mg of vitamin C with a diet increased iron intake by 67%. However, people with a high risk of iron buildup in the body, such as hemochromatosis, should be wary of vitamin C supplements.
In these situations, overloading vitamin C can lead to iron overload, which can cause severe damage to the heart, liver, pancreas, thyroid gland, and central nervous system. However, iron overload is rare unless there are conditions that increase iron absorption. In addition, iron overload is more likely to occur when excess iron is consumed in dietary supplements. (13)
Can cause kidney stones
The body excretes excess vitamin C as oxalate, a waste product from the body. Oxalate usually leaves the body in the urine. However, oxalate can bind to minerals to form crystals, leading to the formation of kidney stones. Too much vitamin C intake increases the amount of oxalate in the urine, increasing the risk of developing kidney stones. (14) In a study in which adults took 1,000 mg of vitamin C twice daily for 6 days, oxalate excretion increased by 20%.
High doses of vitamin C are associated with high levels of oxalate in the urine and the formation of kidney stones, significantly above 2,000 mg. There are also reports of renal failure in patients taking 2,000 mg or more per day. But this is very rare, especially in healthy people. (15)
How much vitamin C should you take?
Vitamin C is water-soluble and is over-excreted by the body within hours of ingestion, making it difficult to overdose. It is almost impossible to overdose on vitamin C from food alone. In healthy people, additional vitamin C consumed more than the recommended daily dose is washed away from the body. (16)
You need to take 29 oranges or 13 peppers before your intake reaches the permissible limit to make an outlook. However, taking supplements increases the risk of vitamin C overdose and can lead to vitamin C overdose. For example, people at increased risk of iron overload or prone to kidney stones should take vitamin C. (17) (18)
All side effects of vitamin C, including indigestion and kidney stones, appear when people take large doses of over 2,000 mg. When deciding on a vitamin C supplement, it is best to choose one that contains less than 100% of your daily needs. It is almost impossible to overdose on vitamin C from food. However, supplementation with this vitamin can minimize the risk of overdose by keeping it below 90 mg per day for men and 75 mg per day for women. (19) (20)
Since people cannot make vitamin C, people must eat foods that contain enough vitamin C to meet their daily needs. If someone is at risk for vitamin C deficiency, they can take vitamin C supplements.
During pregnancy or lactation, women are required to receive the following daily vitamin C levels: (21)
- 14-18 years: 80 mg during pregnancy, 115 mg during lactation
- 19 years and older: 85 mg during pregnancy, 120 mg during lactation.
As a result, ODS provides a “sufficient intake.” This is an amount that is likely to be sufficient. 40 mg for 0–6-month babies 50 mg for 7–12-month babies
Conclusion:
Vitamin C is safe for most people. This is especially true when ingested from foods rather than dietary supplements. People who take vitamin C in the form of supplements are at increased risk of overeating and experiencing side effects, the most common of which are gastrointestinal symptoms. However, more serious consequences such as iron overload and kidney stones can result from taking extreme amounts of vitamin C.
Fortunately, it is easy to prevent these potential side effects-avoid vitamin C supplements. Unless you have vitamin C deficiency, which is rare in healthy people, you do not need to take large amounts of this vitamin.