Vitamin C: Daily requirement

How high is the daily requirement of vitamin C, and how can it be met? Your need depends above all on age, gender and lifestyle — here is what the reference values say and how to cover them.

Vitamin C daily requirement at a glance

• How much vitamin C you need depends in particular on age, gender and lifestyle.
• Adult women need 95 mg and adult men 110 mg of vitamin C per day.
• The daily requirement is increased among people with certain diseases, pregnant women and competitive athletes, among others.
• Healthy people can ensure a needs-based supply by eating fruit and vegetables regularly.
• Risk groups and people with an existing deficiency may need a vitamin C supplement.

How much vitamin C do you need?

The amount of vitamin C required depends primarily on age and gender. Additionally, lifestyle factors can influence the necessary intake of ascorbic acid.

The German Nutrition Society (DGE) has established the following reference values for daily vitamin C intake:

• 95 mg for adult women
• 110 mg for adult men
• 20 to 65 mg for infants and children up to 13 years old
• 85 mg for adolescents aged 13 to 15 years
• 90 mg for female adolescents aged 15 to 19 years
• 105 mg for male adolescents aged 15 to 19 years

Who has an increased daily requirement for vitamin C?

In certain situations, the requirement for vitamin C may be higher. This is the case, for example, for pregnant and breastfeeding women as well as smokers.

• According to the DGE reference values, male smokers require 155 mg of ascorbic acid per day, while female smokers need 135 mg daily.
• Pregnant women are recommended to consume 105 mg per day from the fourth month of pregnancy onwards, while breastfeeding mothers have an increased requirement of 125 mg per day.

Other causes of an increased requirement

Smoking and pregnancy are not the only potential causes of an increased need for vitamin C. Other factors include:

• intense physical activity (e.g. professional sports)
• heavy physical labour
• metabolic disorders such as diabetes
• chronic inflammatory diseases
• high fever
• alcohol abuse
• certain medications
• hormonal contraceptives

What is the function of vitamin C in the body?

Vitamin C plays many roles in the body. It is indispensable for collagen formation, which is why it is essential for blood vessels, bones, connective tissue, and teeth.

Additionally, vitamin C contributes to:

• the normal function of the immune system
• the normal functioning of the nervous system
• normal psychological function
• a healthy energy metabolism
• protecting cells from oxidative stress

What happens in the case of a vitamin C deficiency?

If the daily vitamin C requirement is not met, a deficiency can develop over time. This can manifest in various non-specific symptoms, such as fatigue and weakness.

A severe vitamin C deficiency leads to scurvy, a disease that has serious health consequences and can even be fatal without treatment. To treat scurvy, high-dose vitamin C supplements are used.

Symptoms of scurvy may include:

• impaired wound healing
• gum bleeding and inflammation
• haemorrhages in mucous membranes and skin
• dry hair
• dry skin
• diarrhoea
• fever

Severe vitamin C deficiency in infants

In infants, a severe vitamin C deficiency does not result in scurvy but rather in Moeller-Barlow disease. In addition to the symptoms mentioned above, this condition leads to severe growth disorders.

What causes a deficiency?

A diet-related deficiency is rare in industrialised countries such as Germany and Austria. Most cases are due to underlying conditions that increase the body’s need for vitamin C or impair nutrient absorption.

Which foods contain vitamin C?

Vitamin C is found almost exclusively in plant-based foods. Good sources of this water-soluble vitamin include various vegetables, certain herbs, and fresh fruits such as citrus fruits. Animal products contain little to no ascorbic acid and do not significantly contribute to vitamin C intake.

Foods high in vitamin C

Examples of foods rich in vitamin C (milligrams per 100 grams):

Note: The exact vitamin C content may vary depending on the harvest time and growing conditions.

Vitamin C as a food additive

Due to its antioxidant properties, vitamin C is often used as a food additive in processed products, such as meat and sausages, to improve shelf life.

How can you meet your daily vitamin C requirement through diet?

A balanced diet that includes daily servings of fruit and vegetables generally ensures an adequate supply of vitamin C. For example, the following can meet the daily requirement:

• 100 g of peppers
• 50 to 60 g of blackcurrants
• 200 g of spinach
• two kiwis

What should you consider when storing and preparing vitamin C-rich foods?

The vitamin C content of foods can decrease during storage and cooking. To minimise loss, it is best to consume fresh fruit and vegetables shortly after purchase and to cook vegetables briefly by steaming or blanching.

Can you consume too much vitamin C?

If vitamin C intake comes solely from food, an overdose is practically impossible. However, taking high-dose vitamin C supplements may lead to minor side effects if excessive amounts are consumed.

What happens when taking high-dose vitamin C?

The body cannot store water-soluble vitamin C, and it has a short half-life. Excess amounts are excreted in urine. However, doses of three to four grams may cause digestive issues such as diarrhoea and bloating.

Is 1,000 mg of vitamin C too much?

A daily dose of 1,000 mg of vitamin C is generally not considered harmful. Healthy individuals can typically tolerate this amount without adverse effects, although it does not provide any additional benefits for them. However, people with haemochromatosis (iron overload) should be cautious and avoid exceeding 500 mg per day, as vitamin C enhances iron absorption.

What is the maximum daily vitamin C intake?

• Because vitamin C has low toxicity and data are insufficient, the European Food Safety Authority (EFSA), which is responsible for food safety in the European Union, has not yet established a maximum daily intake.
• The German Federal Institute for Risk Assessment (BfR) recommends a maximum of 250 milligrams per daily dose of vitamin C in food supplements, 60 milligrams per 100 grams for fortified foods, and 16 milligrams per 100 millilitres for beverages.

When is taking vitamin C supplements useful?

Most people can meet their daily vitamin C requirements through diet alone. Supplements are only necessary if an additional requirement exists or a deficiency is present. This may be the case for professional athletes or individuals with certain medical conditions. However, when taking vitamin C supplements, it is advisable to choose products that release ascorbic acid slowly, ensuring maximum absorption by the body.

Important to know

If you are not a medical specialist and have complaints, specific health conditions, or suspect deficiencies, please make sure to consult a doctor to discuss this.