Is a vitamin C overdose even possible? So much is said about its deficiency, but can excess ascorbic acid also be dangerous to health?
Vitamin C is a water-soluble compound, so excess ascorbic acid is excreted from the body with urine. However, does the excessive supply of the substance remain indifferent to the body, or can it have negative health effects?
What is vitamin C and what functions does it have in the body?
Vitamin C, also known as ascorbic acid, is an organic chemical compound from the group of polyhydroxy alcohols. It is one of the water-soluble vitamins, which is necessary for the proper functioning of the human body.
Vitamin C can affect immune and nervous system function. Is essential for the proper functioning of connective tissue and bones. It can accelerate wound healing and also participate in the regulation of collagen production. It is one of the main antioxidants that protect the human body from free radicals and oxidative stress.
The need for vitamin C
According to the Nutrition Standards developed by the Institute of Food and Nutrition, the daily demand for vitamin C among adult women is 75 mg, while among men it is 90 mg.
Increased demand can be observed among pregnant and lactating women, as well as among the elderly or people exposed to prolonged stress.
Can vitamin C be overdosed?
Vitamin C is a water-soluble compound, so excess is removed from the body on an ongoing basis with urine. However, this does not mean that too much vitamin C remains indifferent to human health.
A single use of a very large dose of ascorbic acid or long-term use of significant portions of the supplement (more than 1,000 mg per day) can lead to an overdose of vitamin C.
However, the possibility of an overdose of a vitamin supplied to the body only with the diet seems unrealistic.
Taking excessive amounts of ascorbic acid can be particularly dangerous among people who struggle with kidney dysfunction. Then the excretion of excess vitamin C from the body may be hindered.
Symptoms of excess vitamin C in the body
Although ascorbic acid is not toxic, excess vitamin C in the body can contribute primarily to gastrointestinal ailments, such as:
- nausea,
- stomach aches,
- bloating,
- heartburn,
- vomiting.
Sometimes there may also be skin changes, manifested by the appearance of a rash or itching.
With chronic intake of excessive portions of vitamin C, painful attacks of renal colic may also occur.
Effects of excess vitamin C in the body
A single exceedance of the recommended portion of the supplement is usually not dangerous, and the excess substance is removed from the body with urine. However, chronic use of high doses of vitamin C can lead to serious health consequences.
Long-term, excessive supply of ascorbic acid can contribute to an increase in oxalic acid, which can result in crystallization of oxalates and eventually contribute to urinary tract stones.
In addition, hypervitaminosis can be dangerous for people with associated iron metabolism disorders, such as hemochromatosis or thalassemia. Since ascorbic acid increases the absorption of iron from the gastrointestinal tract, in the presence of the listed conditions, the disorder may be aggravated.
Management of vitamin C overdose
In case of an overdose of vitamin C and the occurrence of undesirable ailments and symptoms, reduce the portion taken or stop ascorbic acid supplementation altogether.
It is also worth increasing fluid intake to remove excess substances from the body with urine.
How not to overdose on vitamin C?
Providing ascorbic acid only naturally with the daily diet, it is extremely difficult to consume excessive amounts of vitamin C.
To supply the body with more than 1,000 mg of the compound, a dose that could contribute to adverse symptoms, one would have to eat 20 kg of apples. It's not likely that any of us (even big apple lovers) provide such quantities of fruit to our menus every day.
It is definitely easier to overdose on vitamin C by taking it in the form of dietary supplements. To ensure an adequate supply of ascorbic acid, follow the manufacturer's instructions on the package and listen to your body.
Bibliography:
- Doseděl M, Jirkovský E, Macáková K, et al. Vitamin C-Sources, Physiological Role, Kinetics, Deficiency, Use, Toxicity, and Determination.Nutrients. 2021;13(2):615. Published 2021 Feb 13. doi:10.3390/nu13020615
- Ferraro P, Curhan G, Gambaro G, Taylor E. Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones. Am J Kidney Dis 2016 Mar;67(3):400-7. doi: 10.1053/j.ajkd.2015.09.005.Epub 2015 Oct 14.
- Spolestra-de-Man A, Elbers P, Oudemans-Van-Straaten H. Vitamin C: should we supplement? Curr Opin Crit Care 2018 Aug;24(4):248-255 doi:10.1097/MCC.0000000000000510.
