Vitamin C is an essential vitamin with a critical role to play in many body functions, including the development, repair and maintenance of muscle, collagen in bones, cartilage and blood vessels. It also boosts the immune function and is vital in the body's healing process in case of an illness or injury. Further, the nutrient aids in the absorption and storage of iron.

Vitamin C is an antioxidant and helps to safeguard body cells from the destructive effects of free radicals. These are harmful particles produced during the digestion process, when food is broken down or when a person is exposed to harmful radiation and smoke, especially from tobacco and fossil fuels. Free radicals can lead to chronic illnesses such as respiratory diseases, cancer and heart disease. Vitamin C may also aid in the prevention or treatment of many diseases.

Therefore, a vitamin C deficiency can cause many severe health problems, including anaemia, weakness, bruising, slow and poor wound healing (scurvy), bleeding gums, fatigue, and rash. 

Diet is the primary source of vitamin C because it is not produced in the body. The nutrient occurs in citrus fruits, peppers, cabbage, potatoes, berries, broccoli, spinach, brussels sprouts, tomatoes, etc. Vitamin C dietary supplements are also widely available.
 

Also Known As

  • Ascorbic acid

 

Types

Vitamin C products are available in various forms, including:

  • Tablets
     
  • Capsules
     
  • Gummies
     
  • Chewable tablets
     
  • Effervescent tablets and powders

 

Uses

The vitamin C has many medical benefits, including:

Age-related macular degeneration (AMD)
The eye disorder can cause loss of sight in older adults. A combination of vitamins C and E beta-carotene, and zinc might prevent or slow down the development of AMD in patients at an increased risk of getting the advanced form of the condition. However, it’s not yet clear whether the combination helps patients at lower risk for developing advanced AMD.

Cataracts
A diet with higher amounts of vitamin C is associated with lower chances of developing cataracts. Research also indicates that people who take vitamin C supplements for over ten years have lower chances of developing cataracts.

Common Cold
Vitamin C dietary supplements may help to boost the body’s immune function. People who take vitamin C regularly can handle a cold much better because the symptoms are less severe, and it lasts fewer days.

High Blood Pressure
Vitamin C in higher doses may have a mild diuretic effect and promote the removal of excess fluids from the body. It might help reduce the pressure within the blood vessels.

Heart Disease
Vitamin C antioxidant properties might help to prevent heart disease by reducing the oxidative stress linked with chronic conditions. 

Cancer
A diet high in vitamin C rich vegetables and fruits may decrease the risk of some forms of cancer, including cancers of the lung, colon and breast. Note that taking dietary vitamin C supplements doesn't provide the same benefit.

Vitamin C can also be useful in a wide range of health conditions, including:

  • Gout
     
  • Sunburn
     
  • Osteoarthritis
     
  • Wrinkled skin
     
  • Lead poisoning
     
  • Pain after surgery
     
  • Irregular heartbeat (atrial fibrillation)
     
  • Airway infections caused by exercise
     
  • Inflammation of the stomach (gastritis) 
     
  • Emptying the colon before a colonoscopy
     
  • Skin redness due to injury or irritation (erythema) 
     
  • Eye damage in patients taking interferons (interferon-related retinopathy) 

 

Dosage

Usually, people obtain adequate vitamin C supplies from a healthy diet. Some people, however, especially patients having gastrointestinal disorders and certain forms of cancer, are vulnerable to inadequate levels or a deficiency in vitamin C. They can benefit from taking dietary supplements. 

The recommended dietary allowance (RDA) is:

Children: ages and recommended dosage per day:

  • 0 to six months - 40 mg 
     
  • Seven to one year - 50 mg 
     
  • One to three years- 15 mg 
     
  • Four and eight years- 25 mg
     
  • Nine to 13 years- 45 mg 
     

Females’ ages and recommended dosage per day:

  • 14 to 18 years - 65 mg 
     
  • 19 and over - 75 mg 
     

Pregnant females’ ages and recommended dosage per day:

  • 14 to 18 years - 80 mg 
     
  • 19 and over - 85 mg 
     

Breastfeeding females’ ages and recommended dosage per day:

  • 14 to 18 - 115 mg 
     
  • 19 and over - 120 mg 
     

Males’ ages and recommended dosage per day:

  • 14 to 18 years- 75 mg 
     
  • 19 and over - 90 mg 
     

Smokers are advised to take an extra 35 mg daily. Patients diagnosed with a vitamin C deficiency may need to take between 100 and 200 mg per day until their blood levels normalize.
 

Potential Side Effects

Vitamin C dietary supplements are generally safe when used in the appropriate doses. The side effects are often dose-related and include:

  • Fatigue
     
  • Nausea
     
  • Diarrhea
     
  • Vomiting
     
  • Insomnia
     
  • Headache
     
  • Heartburn
     
  • Sleepiness
     
  • Skin flushing
     
  • Stomach cramps
     
  • A swelling that causes damage to the esophagus 
     
  • An intestinal blockage that prevents the movement of food through the intestines (intestinal obstruction)
     

In some patients, dietary supplements might lead to the development of kidney stones. Moreover, prolonged use of over 2,000 mg daily raises the risk of significant side effects.

It is advisable to see a doctor before taking vitamin C supplements.
 

Interactions

Vitamin C possible interactions include:

Estrogen
Using the dietary supplement with hormone replacement therapy or oral contraceptives can increase estrogen levels. It slows the excretion of estrogen from the body and might also raise the risk of hormonal side effects.

Aluminum
Vitamin C may increase a patient’s aluminum absorption from medications that contain aluminum, like phosphate binders. It might be detrimental to patients with kidney disorders.

Protease inhibitors
The vitamin C supplement may lower the effect of antiviral drugs.

Chemotherapy
It is suspected that taking antioxidants, like vitamin C, during chemotherapy can diminish the impact of the drug.

Warfarin (Jantoven, Coumadin)
Larger doses of the dietary supplement may decrease a patient’s response to the anticoagulant.

Statins & niacin
Although combining niacin with vitamin C may benefit patients with high cholesterol, it can minimize the effect of niacin.

A patient should inform the doctor if they are taking or planning to use the dietary supplement with these types of medications to avoid interactions.