What is vitamin C?
Vitamin C is a water-soluble vitamin. The body must absorb it regularly with food. Vitamin C is found mainly in citrus fruits and fresh vegetables.
In addition, vitamin C is added to many processed products such as sausages and meat products as an additive (E300 to E304, E315 and E316). It makes them more durable and maintains the original color.
What is vitamin C good for? Many metabolic processes in the human body require vitamin C. For example, the vitamin has an effect on the optimal functioning of the immune system.
What is ascorbic acid and what is L-ascorbic acid?
There are four different stereoisomeric forms of ascorbic acid. Stereoisomers are compounds with the same chemical formula and the same constitution, but different spatial structure. One of them is L-ascorbic acid. Only it exhibits biological activity, i.e. only it has an effect on living tissue.
What are the functions of vitamin C in the body?
The positive effect of vitamin C on the immune system is particularly well known: the body needs the vitamin for a strong defense system.
Ascorbic acid also promotes the absorption and utilization of iron from plant foods. It is needed to produce bile acids and catecholamines such as norepinephrine and epinephrine. In addition, vitamin C intercepts cell-damaging oxygen compounds in the body – so-called “free radicals”, which are produced during normal metabolic processes, but also by UV radiation, nicotine and drugs.
Furthermore, vitamin C is important for the formation of connective tissue (collagen), blood clotting and wound healing.
Vitamin C: Skin protector and shelf-life maker
Cosmetic manufacturers particularly value the antioxidant properties of vitamin C. As a radical scavenger, it defuses aggressive oxygen compounds (free radicals) – with a double benefit: On the one hand, ascorbic acid thus protects cosmetic products from spoilage through contact with oxygen (oxidative spoilage). Secondly, thanks to vitamin C, oxidative stress for the skin is reduced. If too many free radicals accumulate in a cell, they can damage or even destroy it – the skin ages faster.
Vitamin C for colds
For the immune system to function, we need vitamin C. Therefore, it seems reasonable to assume that a lot of vitamin C can prevent or alleviate colds, sniffles and the like. However, the scientific data are less clear:
There are indications of a preventive effect primarily in people who are very active in sports or otherwise subject to high physical stress. On the other hand, it has not been proven that the daily intake of vitamin C supplements generally benefits everyone in terms of prevention.
Some studies, on the other hand, indicate that a cold heals more quickly with high doses of vitamin C. In other studies, this effect has not been observed. In other studies, this effect has not been confirmed or has only been partially confirmed, for example for young children. And basically, you can catch a cold even with an extra dose of vitamin C.
Vitamin C against cancer
What is the daily requirement for vitamin C?
According to the German Nutrition Society (DGE), the recommended intake of vitamin C for adolescents aged 15 and over and adults is between 90 and 110 milligrams per day. This is a reference value, i.e. a standardized recommended daily intake throughout Europe, which a healthy person of normal weight should consume daily to cover his or her average requirements.
In part, it also depends on gender how much vitamin C one needs per day. In addition, other factors influence the vitamin C requirement, for example environmental, physical or psychological stresses and illnesses. The daily vitamin C requirement can also be increased during the breastfeeding period.
This is how much vitamin C you should take in according to the DGE recommendation:
|
Vitamin C mg/day |
||
|
Male |
female |
|
|
Infants |
||
|
0 to under 4 months |
20 |
20 |
|
4 to under 12 months |
20 |
20 |
|
Children |
||
|
1 to under 4 years |
20 |
20 |
|
4 to under 7 years |
30 |
30 |
|
7 to under 10 years |
45 |
45 |
|
10 to under 13 years |
65 |
65 |
|
13 to under 15 years |
85 |
85 |
|
Adolescents and adults |
||
|
15 to under 19 years |
105 |
90 |
|
19 to under 25 years |
110 |
95 |
|
25 to under 51 years |
110 |
95 |
|
51 to under 65 years |
110 |
95 |
|
65 years and older |
110 |
95 |
|
Pregnant |
105 |
|
|
Breastfeeding |
125 |
Vitamin C: Foods with high content
According to the German Nutrition Society (DGE), you can easily achieve the recommended vitamin C intake through your diet. For an optimal supply the DGE advises five portions of vegetables and fruit daily. Important: Ascorbic acid does not tolerate heat very well. Vegetables should therefore only be steamed briefly. Even when preparing the “hot lemon” so popular with colds, the vitamin C content is quickly reduced by the hot water.
If a vitamin C deficiency is suspected, the doctor determines the vitamin C level in the blood. It is not clear whether the blood test actually does any good. Normal values are not clearly defined and it is therefore difficult to assess the level of vitamin C correctly.
Vitamin C: Normal values
The concentration of vitamin C is determined from the blood. It is usually 5 to 15 milligrams per liter.
How does a vitamin C deficiency manifest itself?
A vitamin C deficiency can occur, for example, in the case of an unbalanced diet low in vitamins, such as in alcoholics. Vitamin C levels may also be too low in gastrointestinal diseases, because absorption of the vitamin in the intestines is impaired.
In certain situations, the vitamin C requirement is increased, so it is easier for an undersupply to occur. This applies, for example, during pregnancy and breastfeeding, physical work, infections, stress and smoking.
How does an excess of vitamin C manifest itself?
Since vitamin C is water-soluble, excess ascorbic acid is simply excreted in the urine, so an excess hardly ever occurs.
Normally, a healthy person can cope well with a vitamin C surplus. However, there are exceptions, read more about this in the article Vitamin C overdose.