All about vitamin C
In this session you’ll learn everything you need to know about vitamin C. We’ll tell you which foods you can find it in, what you need it for and how you can recognise deficiencies.
All about vitamin C
Essential and very delicate
Vitamin C is of great importance for your body. You need to consume it regularly because the body cannot store it well. Which foods contain it, what is it good for and how much of it do you need in order to stay healthy?
What is vitamin C?
Vitamin C is also called ascorbic acid and belongs to the essential vitamins. It cannot be produced nor stored by the human body as it is water-soluble. While the body can store fat-soluble vitamins well, this does not apply to water-soluble ones – so you have to consume them regularly through food.
Fresh, raw fruits and vegetables contain the most vitamin C
Vitamin C is sensitive to heat, water, oxygen and light. The vitamin C content in any given food can therefore vary depending on the moment of harvest, transport, duration and type of storage. The preparation method also has a significant influence on the vitamin C content. A bell pepper that has been in the refrigerator for several days and is then chopped and cooked has hardly any vitamin C left.
Rule of thumb: It should still be “al dente”.
What do we need vitamin C for?
Vitamin C is necessary for many metabolic processes. These include the formation of connective tissue, bones and teeth. It strengthens the immune system and protects cells from damage by free radicals, i.e. it has an antioxidant effect.
It also improves the absorption of plant-based iron and supports the digestive system in metabolising it. Vitamin C is even said to prevent cancer: It inhibits the formation of carcinogenic nitrosamines. Those are compounds of nitrite (salts of nitrous acid) and amines (organic compounds that are formed, for example, when protein-containing food is being cooked). Nitrosamines can also result from overheating foods containing nitrites. They are found, for example, in cured meat or fish.
And there are even more positive effects: Vitamin C is good for the psyche and reduces tiredness, as it is involved in the formation of the neurotransmitters dopamine and adrenaline.
Vitamin C is extremely important for our health!
How much vitamin C do we need?
How much should it be?
The reference values are 95 mg/day for women and 110 mg/day for men. If you smoke, you should increase your intake: as a woman you need 135 mg/day and as a man 155 mg/day.
Pregnant women (105 mg/day from the fourth month) and breastfeeding women (125 mg/day) also need a greater amount. Children under four years of age need 20 mg/day, between four and seven they need 30 milligrams, up to ten years 45, up to 13 years 65, up to 15 years 85 and up to 19 years 105 milligrams per day for boys and 90 milligrams per day for girls.
How to attain the amount needed?
In the next section we will show you which fruits and vegetables are particularly rich in vitamin C. For example, you can reach your daily requirement with half a red pepper and one orange.
Sources of vitamin C
Which foods contain vitamin C?
The most important sources are vegetables and fruits. It is also contained in processed foods: It is, for example, added as an antioxidant (e.g. E 300) and gives sausage products their reddish colour. You can also find food supplements containing vitamin C. You can recognise it by its name, such as L-ascorbic acid or L-ascorbate.
Foods particularly rich in vitamin C
Citrus fruits are among the best-known sources of vitamin C. But there are fruits and vegetables that contain even more of it. A few examples of fruits (values given per 100 grams)
- Acerola (1700 mg)
- Rosehip (1250 mg)
- Sea buckthorn (450 mg)
- Guava (270 mg)
- Blackcurrant (200 mg)
- Papaya (68 mg)
- Satsuma (61 mg)
- Strawberry (58 mg)
- Orange (52 mg)
- Cornelian cherry (100 mg)
- Kiwi (78 mg)
- Lemon (55 mg)
- Grapefruit (36 mg)
Two oranges cover the daily need of vitamin C
Examples of vegetables rich in vitamin C (values given per 100 grams):
- Nettle (333 mg)
- Parsley (182 mg)
- Brussels sprouts raw (159 mg)
- Wild garlic (150 mg)
- red bell pepper (150 mg)
- Horseradish (114 mg)
- Broccoli raw (109 mg)
- Kale raw (74 mg)
- Spinach raw (40 mg)
- Cress (38 mg)
- Rocket (15 mg)
- Corn salad (24 mg)
Incidentally, if you consume too much vitamin C, your body will simply excrete the excess. Only if you ingest a very high dose (more than three to four grams per day) can the body react with diarrhoea, and you run a risk of bladder and kidney stones.
Please note: If you suffer from reduced kidney function, if your body absorbs too much iron from food (iron accumulation) or if you are undergoing chemotherapy, high doses of vitamin C are not recommended. Be sure to talk to your doctor about this.
What happens in case of undersupply?
People who take in too little vitamin C for several months risk developing scurvy (or Möller-Barlow disease in young children). Among seafarers, scurvy used to be widespread and frequently ended in death from heart failure.
Symptoms of an undersupply are increased susceptibility to infections, bleeding gums, muscle atrophy, exhaustion, inflammation of the joints, diarrhoea, dizziness and poorly healing wounds. Due to the lack of vitamin C, the body cannot produce enough collagen (important fibrous proteins in connective tissue). Even though this disease almost never occurs in Europe, scurvy can be treated with a sufficient supply of vitamin C.
Hippocrates was the first to write about scurvy around 400 BC. In the 18th century, a ship’s doctor named James Lind proved that citrus fruits could alleviate the symptoms.
Nutrients combining well with vitamin C
Vitamin C improves the absorption of iron, as has already been mentioned. If you are taking iron supplements, it is helpful to eat a kiwi or a handful of strawberries with them. This also applies to foods that contain iron. Thus, we recommend combining pulses and whole-grain products with broccoli and other vitamin C-rich vegetables.
Another good combination is vitamin C and calcium (for example in the form of tomatoes with mozzarella or salmon with leafy vegetables and lemon). And if you want to lose weight, you can consume vitamin C with protein. This could be in the form of low-fat curd cheese, 2 egg whites and the juice of one lemon. This combination stimulates the metabolism and thus fat loss.
The combination of the vitamins A, C and E is well-known, for example as juice consisting of oranges, carrots and apples. In most cases, vitamin A is present in the form of the provitamin beta-carotene. The mixture is healthy, but because commercial ACE juice often contains a lot of sugar, it’s better to prepare it yourself from fresh ingredients in a juicer.
If you don’t want to drink juice, you can also get the A-C-E combination in the form of food containing these vitamins. Beta-carotene and vitamin C can be found in carrots, kale, peppers, spinach or papaya, while vitamin E can be found in nuts or oils such as safflower or sunflower oil.
How about a spinach salad with safflower oil, a little lemon juice, honey and hazelnuts?
However, the combination of selenium in the form of sodium selenite and vitamin C does not go well together. This combination can lower the selenium serum level as the sodium selenite can be converted by the vitamin C into a form which cannot be absorbed by the body (recommendation: wait one hour between the two).
If you take a multivitamin supplement (which is not usually necessary for healthy people on a balanced diet), make sure it does not contain both.
Overview
A balanced diet will provide you with enough vitamin C. However, if you smoke, are pregnant or breastfeeding, your needs are higher and you should take this into account. In most cases, it is not necessary to take nutrient supplements because there are plenty of vitamin C-rich foods.