What causes vitamin C deficiency, and how to prevent it

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According to the National Institutes of Health (NIH), the recommended dietary allowance (RDA) for vitamin C is:

• 90 milligrams (mg) per day for males
• 75 mg per day for females

Depending on age, children require 15 mg to 75 mg daily and sometimes more in certain situations.

The NIH uses the term “vitamin C deficiency” to refer to a daily vitamin C intake of less than 10 mg. It also uses the term “vitamin C inadequacy” to refer to a daily vitamin C intake that exceeds 10 mg but falls short of the RDA.

As the NIH explains, vitamin C deficiency is rare in the United States and other developed countries. Nonetheless, it can occur in individuals who have a limited diet and in those with certain health conditions.

Some factors that increase a person’s risk of vitamin C inadequacy or deficiency include:

• limited food variety, which may occur due to:
  • following a restrictive diet
  • disliking and avoiding many foods
  • mental health issues
  • alcohol or substance misuse
• smoking or exposure to secondhand smoke
• medical conditions that reduce vitamin C absorption or increase the body’s vitamin C requirements, such as:
  • severe intestinal malabsorption
  • muscle wasting
  • certain cancers
  • end stage kidney disease
  • long-term dialysis

According to the NIH, obvious symptoms of vitamin C deficiency only occur when a person’s vitamin C intake falls below 10 mg per day for several weeks. This results in scurvy, which is a rare condition.

Initial symptoms of scurvy may include:

• malaise
• fatigue
• gum inflammation

As vitamin C deficiency progresses, the body will not have enough vitamin C to help synthesize collagen, a type of protein. This leads to weakness of the connective tissues, which may result in the following signs and symptoms:

• hyperkeratosis, which is a thickening of the outer layer of the skin
• petechiae, which are small blood spots beneath the surface of the skin or mucus membranes
• purpura, which is a rash of purple spots due to bleeding from small blood vessels beneath the skin
• bruising
• corkscrew hairs
• wound healing issues
• joint pain

Other potential signs and symptoms of scurvy include:

• depression
• bleeding gums
• tooth loss
• iron deficiency anemia

Learn more about scurvy.

According to a 2022 review, blood tests to check plasma and ascorbic acid levels can confirm a diagnosis of scurvy. Ascorbic acid is another name for vitamin C.

The review adds that ascorbic acid levels below 0.2 mg per deciliter of blood indicate severe vitamin C deficiency.

Doctors may also conduct a skin biopsy to help with diagnosis. If a vitamin C deficiency is present, biopsies may show signs of the following:

• thickening of the skin surrounding the hair follicles
• bleeding around the hair follicles
• corkscrew hairs
• a large number of blood vessels

Untreated scurvy can cause serious and potentially life threatening problems, so prompt treatment with vitamin C supplementation is necessary.

A 2023 review explains that the vitamin C dosage necessary to treat scurvy depends on the severity of the condition and a person’s age and requirements. The authors state that children may require up to 300 mg per day, while adults may require between 500 mg and 1000 mg per day.

For some adults, doctors may recommend a starting dose of 2 grams per day for the first 3 days, followed by 500 mg per day for 1 week, and then 100 mg daily for 1 to 3 months.

A 2022 review notes that most people who undergo treatment for scurvy find that their symptoms resolve within days or weeks of starting treatment.

Learn about why vitamin C is important.

The best way to prevent scurvy is to eat a healthy, balanced diet rich in fruits and vegetables. People can also consider taking a vitamin C supplement, but those who are pregnant or breastfeeding need to consult a doctor first.

As a 2023 review explains, certain lifestyle factors increase an individual’s daily vitamin C requirement. These include:

• Pregnancy: Pregnant individuals require 85 mg of vitamin C per day.
• Lactation: People producing breastmilk require 120 mg per day.
• Smoking: People who smoke or receive secondhand smoke exposure require an additional 35 mg per day.

Find the 7 best vitamin C supplements.

According to the NIH, fruits and vegetables are the best sources of vitamin C. A person who eats a variety of these foods should meet their RDA of vitamin C through diet alone.

The NHS lists some fruits and vegetables that are particularly high in vitamin C. These include:

• citrus fruits and juices
• red and green peppers
• strawberries
• blackcurrants
• broccoli
• Brussels sprouts
• potatoes

The NIH adds that cooking foods can reduce their vitamin C content. Steaming or microwaving may be better at retaining the vitamin C content.

Read more about foods high in vitamin C.

The outlook for people who receive treatment for vitamin C deficiency is positive. Most individuals notice an improvement in their symptoms within days or weeks of taking high dose vitamin C supplements.

Vitamin C deficiency is rare in the United States and other developed countries but can occur in people with limited diets and those with certain medical conditions.

Early symptoms of vitamin C deficiency may include malaise, fatigue, and swollen gums. Prolonged deficiency can cause more severe symptoms and even death.

The treatment for vitamin C deficiency is high dose vitamin C supplementation. Most people who receive this treatment notice an improvement in symptoms within days or weeks of starting the treatment.

The best way to prevent vitamin C deficiency is to eat a healthy and balanced diet that is rich in fruits and vegetables.