Vitamin C is probably the best-known of all vitamins. Already in school, we learn that our body and especially our immune system need a daily portion of vitamin C.
But how does vitamin C actually support the immune system? Are oranges, grapefruits and lemons real vitamin C bombs, or are there good regional alternatives?
We have compiled the most important information about vitamin C for you.
Table of Contents
- Vitamin C and Ascorbic Acid
- Recommended Vitamin C Intake
- Daily Vitamin C Requirement and Exceptions
- What Function Does Vitamin C Have for Our Body?
- Biological Effects of Vitamin C
- Vitamin C: Foods and Occurrence
- Vitamin C: Storage and Preparation
- Vitamin C: Deficiency
- Conclusion: The Most Important Facts About Vitamin C at a Glance
1. Vitamin C and Ascorbic Acid
The chemical name for vitamin C is ascorbic acid. If you see this name on an ingredient list, you now know that it refers to vitamin C.
Vitamin C, like B vitamins, is a water-soluble vitamin. This means that the body's absorption of the vitamin is independent of fat intake, unlike, for example, vitamin A or D.
While plants and animals (with the exception of guinea pigs) can produce vitamin C themselves, humans lack a specific enzyme (L-gulonolactone oxidase) for this.
We must regularly and daily consume the vitamin through food. The body's stores of vitamin C are small, with a reserve capacity of approximately 2-6 weeks.
Excess vitamin C consumed through food is simply excreted by the body in the urine.
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2. Recommended Vitamin C Intake
The recommended intake of vitamin C for women is 95 mg per day. During pregnancy, the recommended vitamin C intake increases to 105 mg, and while mothers are breastfeeding, an intake of 125 mg of zinc per day is recommended. For men, the daily recommended intake is 110 mg of vitamin C.
Children and adolescents are advised to consume between 20 and 85 mg of vitamin C per day, depending on their age. Babies have a slightly higher requirement, at approximately 6 mg of vitamin C per kg of body weight.
3. Daily Vitamin C Requirement and Exceptions
For people who smoke, there is a separate and increased recommended intake. This is 135 mg for women and 155 mg of vitamin C per day for men. This is due to an increased need and consumption of vitamin C as protection against harmful substances (antioxidant) such as cigarette smoke.
Not only pregnancy and nicotine consumption increase the body's need for vitamin C. When taking medications such as antibiotics or the birth control pill, it is also particularly important to ensure sufficient intake.
4. What Function Does Vitamin C Have for Our Body?
Our body primarily needs vitamin C for a well-functioning immune system, for wound healing, and for the formation of connective tissue. Vitamin C improves iron absorption from food or supplements.
The following points summarize the most important functions and areas of action of vitamin C:
- Antioxidant (free radical scavenger)
- Collagen biosynthesis (hydroxylases)
- Activation of neuroendocrine hormones (e.g., adrenaline)
- Bodily detoxification (cytochrome)
- Promotion of iron absorption in the intestine
- Inhibition of nitrosamine formation (carcinogenic substance)
- Tyrosine degradation
- Bile acid synthesis
- Carnitine synthesis
5. Biological Effects of Vitamin C
During some processes in the body, cell-damaging compounds are formed. These are also called free radicals. Free radicals cause oxidative stress.
They are highly reactive and look for suitable cells to bond with. A main property of vitamin C is to function as a scavenger of these free radicals and thus protect the body from oxidative stress.
Ascorbic acid reacts chemically with harmful substances and thereby reduces their reactivity. This way, vitamin C protects the body from tissue or cell-damaging reactions that can be triggered by free radicals.
Free radicals are caused, among other things, by smoking, taking medication, or the effects of UV radiation on our body.
6. Vitamin C: Foods and Occurrence
Vitamin C is found in many foods, as plants and animals can synthesize ascorbic acid themselves. The most important sources of vitamin C are fruits and vegetables.
The following list gives you an overview of the average vitamin C content in 100 g of various foods. The exact vitamin C content varies depending on storage, temperature, and preparation.
- Coriander 566 mg
- Sea buckthorn 450 - 600 mg
- Rosehip 430 mg
- Nettle 330 mg
- Blackcurrant 177 mg
- Parsley 159 mg
- Wild garlic 150 mg
- Red bell pepper 140 mg
- Brussels sprouts 110 mg
- Broccoli 110 mg
- Kiwi 100 mg
- Fennel 93 mg
- Lemon 52 mg
- Orange 50 mg
- Grapefruit 37 mg
- Aronia 15 mg
- Potatoes 10 - 20 mg
As you can see, many native and regionally available fruits and vegetables are particularly rich in vitamin C. So there are wonderful alternatives at the local weekly market or even from your own garden to imported tropical fruits.
Lemons and oranges are rich in vitamin C, but there are many other sources of vitamin C. Foods like herbs, berries, and green vegetables often offer much higher concentrations of vitamin C than citrus fruits from distant countries.
To cover your daily vitamin C needs, for example, the following amounts of fruits and vegetables are sufficient:
- approx. 100 g fennel, kale, or broccoli
- approx. 70 g red bell pepper
- approx. 250 g chard, lamb's lettuce, leek, radish, or radishes
- approx. 200 g spinach or kohlrabi
7. Vitamin C: Storage and Preparation
Heat and storage have a negative impact on the vitamin C content in foods. The cooler and more humid the storage, the more vitamins are retained. Further losses occur during cooking.
Therefore, it is recommended to gently cook fruits and vegetables with low heat. So, do not pour boiling water over lemon juice to prepare the popular hot lemon. The water should be approximately 40 to 60 degrees warm.
8. Vitamin C: Deficiency
On average, the recommended vitamin C intake in Germany is met through a balanced diet. This is because vitamin C is found in most common foods.
Seniors, however, sometimes have an insufficient intake. This is partly due to food that has been reheated multiple times or cooked very soft with too much heat, as there may be difficulties with chewing.
For them, it is advisable to pay more attention to a sufficient intake of vitamin C. The same applies to people with an increased need for vitamin C. This includes pregnant women, breastfeeding women, smokers, as well as in cases of alcohol abuse, high-performance sports, or if you are undergoing antibiotic therapy.
The first signs of a deficiency are unspecific: fatigue, joint pain, or weak muscles. After several weeks of deficiency, serious signs can emerge that indicate scurvy.
Scurvy is the classic deficiency symptom that occurs due to a severe vitamin C deficiency or chronic malnutrition. The vitamin deficiency disease manifests as immune weakness, bleeding gums, and muscle pain.
In Western countries and industrialized nations, scurvy hardly plays a role anymore today. However, scurvy is still an issue in so-called developing countries, where people are sometimes inadequately nourished.
9. Conclusion: The Most Important Facts About Vitamin C at a Glance
It is recommended for men and women to consume approximately 100 mg of vitamin C daily through food. Particularly valuable sources of vitamin C are foods like berries, green vegetables, citrus fruits, and herbs.
Vitamin C is important for our immune system, wound healing, connective tissue synthesis, and improves iron absorption from food.
For people who are pregnant, breastfeeding, taking certain medications like antibiotics, smoking, or are already somewhat older, additional attention should be paid to vitamin C intake. Their needs may be increased or their intake may be insufficient.
Sources:
- Biesalski, H. K.; Grimm, P. & Nowitzki-Grimm, S. (2011). Taschenatlas Ernährung (6. Auflage). Thieme.
- Horn, F. (2009). Biochemie des Menschen. Das Lehrbuch für das Medizinstudium (4. Auflage). Thieme.
- Ebermann, R.; Elmadfa I. (2011). Lehrbuch Lebensmittelchemie und Ernährung (2. Auflage). Springer-Verlag.
All our articles are written by nutritionists and checked for factual quality by expert professionals.
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