Vitamin C, also known as ascorbic acid, is an essential water-soluble vitamin and a powerful antioxidant. It plays a crucial role in numerous biological processes and is vital for maintaining overall health.
Background
The discovery of vitamin C is closely linked to the history of scurvy, a disease caused by vitamin C deficiency. Scurvy was a significant issue among sailors and pirates in the 15th to 18th centuries due to the lack of fresh fruits and vegetables during long sea voyages. The symptoms of scurvy include weakness, fatigue, swollen and bleeding gums, and joint pain, which could progress to death if left untreated.
In 1747, Scottish naval surgeon James Lind conducted a ground-breaking experiment to find a cure for scurvy. He provided different treatments to sailors suffering from the disease and observed that the group receiving citrus fruits, such as lemons and oranges, recovered remarkably. This discovery laid the foundation for understanding the importance of vitamin C in preventing scurvy.
The chemical structure of vitamin C was determined by Albert Szent-Györgyi and Charles Glen King in the early 1930s. In 1933, Norman Haworth successfully synthesised ascorbic acid, making it the first vitamin to be artificially produced. Vitamin C then became widely available as a supplement, and its role in preventing and treating scurvy became well-established.
Functions Of Vitamin C
Vitamin C plays a crucial role in various physiological processes in the body. Some of the primary functions of vitamin C include:
- Collagen synthesis: Vitamin C is essential for the synthesis of collagen, a vital structural protein that provides strength and support for connective tissues such as skin, blood vessels, bones, and tendons.
- Wound healing: Due to its role in collagen production, vitamin C is important for proper wound healing and tissue repair.
- Antioxidant properties: Vitamin C is a powerful antioxidant that helps neutralise harmful free radicals and protects cells from oxidative stress, which can contribute to chronic diseases and aging.
- Immune system support: Vitamin C contributes to the proper functioning of the immune system by supporting the production and function of white blood cells, enhancing the immune response to infections, and modulating inflammation.
- Iron absorption: Vitamin C enhances the absorption of non-haem iron (a form of iron found in plant-based foods) in the digestive system by converting it to a more bioavailable form.
- Neurotransmitter synthesis: Vitamin C is involved in the synthesis of several neurotransmitters, including norepinephrine, which is essential for proper brain function and mood regulation.
- Regeneration of other antioxidants: Vitamin C helps regenerate other antioxidants, such as vitamin E, in the body, maintaining their ability to neutralise free radicals.
Good Sources Of Vitamin C
Vitamin C is abundant in a variety of fruits and vegetables. Some good sources of vitamin C include:
- Citrus fruits: Oranges, grapefruits, lemons, and limes are well-known for their high vitamin C content.
- Kiwifruit: This small, nutrient-dense fruit is an excellent source of vitamin C.
- Strawberries: These juicy, red berries are not only delicious but also rich in vitamin C.
- Pineapple: This tropical fruit is another good source of vitamin C.
- Mango: Packed with vitamin C, mangoes provide a sweet and nutritious treat.
- Papaya: This tropical fruit contains a significant amount of vitamin C and other beneficial nutrients.
- Melons: Both cantaloupe and watermelon contain modest amounts of vitamin C.
Vegetables:
- Bell peppers: red, yellow, and green bell peppers are all excellent sources of vitamin C.
- Broccoli: This cruciferous vegetable is not only rich in vitamin C but also contains many other important nutrients.
- Brussels sprouts: These mini cabbage-like vegetables are high in vitamin C and other essential nutrients.
- Cauliflower: Another cruciferous vegetable, cauliflower, provides a good amount of vitamin C.
- Spinach: This leafy green vegetable contains vitamin C, along with other essential vitamins and minerals.
- Kale: This nutrient-dense leafy green is a great source of vitamin C and many other beneficial compounds.
- Tomatoes: Both raw and cooked tomatoes provide vitamin C, although the content decreases with cooking.
Including a variety of these fruits and vegetables in your diet can help ensure adequate vitamin C intake for maintaining overall health. Keep in mind that vitamin C is sensitive to heat and light, so consuming fresh, raw, or lightly cooked produce is the best way to preserve its nutritional value.
The Dietary Reference Intakes (DRIs) for vitamin C provided by the NIH are as follows:
- Infants (0-6 months)*: 40 mg/day (milligrams)
- Infants (7-12 months)*: 50 mg/day
- Children (1-3 years): 15 mg/day
- Children (4-8 years): 25 mg/day
- Children (9-13 years): 45 mg/day
- Male teens (14-18 years): 75 mg/day
- Female teens (14-18 years): 65 mg/day
- Adult males (19 years and older): 90 mg/day
- Adult females (19 years and older): 75 mg/day
- Pregnant teens: 80 mg/day
- Pregnant women: 85 mg/day
- Breastfeeding teens: 115 mg/day
- Breastfeeding women: 120 mg/day
*For infants, the values provided are Adequate Intakes (AI) rather than DRIs, as there is not enough data to establish DRIs for this age group.
https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
These values are general guidelines, and individual needs may vary depending on factors such as overall health, lifestyle, and dietary choices. It is essential to consume adequate amounts of vitamin C through a balanced and varied diet or supplementation if necessary. If you are concerned about your vitamin C intake, consult with a healthcare professional for personalised advice.
What Are The Signs Of Vitamin C Deficiency?
Vitamin C deficiency can lead to various symptoms, as it plays a vital role in collagen synthesis, immune function, and antioxidant activity. Severe vitamin C deficiency results in a condition called scurvy. Some of the signs and symptoms of vitamin C deficiency include:
- Fatigue and weakness: A lack of vitamin C can lead to feelings of fatigue, weakness, and general malaise.
- Swollen, bleeding gums: Vitamin C is essential for maintaining healthy gums, and deficiency can cause gums to become swollen, red, and prone to bleeding.
- Dry, scaly skin: A deficiency in vitamin C can result in dry, rough, and scaly skin due to impaired collagen production.
- Bruising easily: Inadequate vitamin C levels can cause capillaries to become fragile, leading to easy bruising and slow wound healing.
- Joint pain and swelling: Vitamin C deficiency can affect connective tissues, leading to joint pain, swelling, and reduced mobility.
- Anaemia: Vitamin C is necessary for proper iron absorption, and deficiency can contribute to iron-deficiency anaemia, causing additional symptoms such as pale skin, dizziness, and shortness of breath.
- Weakened immune system: A lack of vitamin C can impair immune function, making individuals more susceptible to infections and illnesses.
- Slow wound healing: Vitamin C is essential for proper wound healing, and deficiency can lead to slow or impaired recovery from injuries.
If you suspect you have a vitamin C deficiency, it is essential to consult with a healthcare professional for proper diagnosis and treatment. Consuming a diet rich in fruits and vegetables high in vitamin C can help prevent deficiency and maintain overall health.
What Happens If I Take Too Much Vitamin C?
Vitamin C is a water-soluble vitamin, which means that any excess is typically excreted through urine. However, taking large doses of vitamin C, particularly in supplement form, can cause some side effects or discomfort in some individuals. Some possible side effects of excessive vitamin C intake include:
- Diarrhoea: Consuming excessive amounts of vitamin C can lead to gastrointestinal issues, such as diarrhoea or loose stools.
- Nausea and stomach cramps: High doses of vitamin C may cause nausea, stomach cramps, or other digestive discomforts.
- Kidney stones: In rare cases, consuming large amounts of vitamin C can increase the risk of developing calcium oxalate kidney stones, particularly in individuals predisposed to kidney stone formation.
- Headaches: Some people might experience headaches after taking high doses of vitamin C.
- Increased iron absorption: High vitamin C levels can enhance iron absorption, which may be harmful to individuals with hemochromatosis or other conditions that cause iron overload.
It is important to note that these side effects are generally associated with consuming very high doses of vitamin C, well above the recommended dietary allowance (RDA). Sticking to the RDA and obtaining vitamin C from a balanced diet rich in fruits and vegetables is the best approach to maintaining optimal health. If you are considering taking vitamin C supplements, consult with a healthcare professional to determine the appropriate dosage based on your individual needs and health conditions.