What is vitamin C?
“Eat fruits and vegetables high in vitamin C, it’s good for you!” You must be familiar with the term. Vitamin C, also known as ascorbic acid, is a water soluble nutrient. Two major functions of vitamin C are as a powerful antioxidant and as an enzyme cofactor; it’s involved in growth, development and repair of body tissues, and prevention of several chronic diseases.
Unlike most mammals, we cannot synthesize vitamin C inside our bodies. And any excess cannot be stored since it passes out through the urinary system. This means we must obtain vitamin C from the diet in a daily basis to maintain good health.
Vitamin C deficiency
An extreme deficiency of vitamin C for long period can cause scurvy; it was a leading cause of death on long voyages among sailors for many centuries, because of lacking fresh fruits and vegetables for their diet. Symptoms of scurvy include subcutaneous bleeding, join pain and swelling, dry and slitting hair, tooth loss, slow wound healing, and eventually death. Such symptoms are related to the weakening of blood vessels, connective tissue, bones and skin, which all contain collagen.
Health benefits of vitamin C :
The importance of vitamin C to prevent scurvy has been known for centuries. More recent researches have expended and provided promising evidence of additional health benefits and clinical applications.
1. Vitamin C as an antioxidant
The importance of vitamin C stems from its powerful antioxidant capacity. Even in small amounts vitamin C can protect indispensable molecules in the body, from damage by free radicals (toxins, pollutants, cigarette smoke, chemotherapy drugs, energy production, and radiation etc.).
2. Improves immune system
It is widely though by the general public that vitamin C boosts immunity; it is found in high concentrations in immune cells, and is consumed quickly during infections. Vitamin C has been shown to stimulate both the production and function of immune cells such as leukocytes (white blood cells), by protecting these cell types from oxidative damage.
3. Disease prevention
Vitamin C is water-soluble and is therefore the best antioxidant to target free radicals within the blood, plasma and tissues. It is well known to prevent and control health conditions including coronary heart disease, stroke, cancer, Alzheimer’s disease, gout and cataracts.
The amount of vitamin C required to help prevent chronic disease is much higher than the amount required for prevention of scurvy.
4. Promotes growth, repair and anti-aging
Collagen is the essential ingredient of connective tissue in the body, it’s found everywhere in musculoskeletal tissues, blood vessels, skin, bone, organ tissue etc. Vitamin C plays a vital role in the biosynthesis of collagen. During aging and metabolism, our body needs continuous collagen formation to meet ongoing needs for growth and repair. Therefore, a sufficient amount of vitamin C intake on a daily basis is critical for strength, flexibility, structural integrity, elasticity and all signs of a well-functioning body.
Because it’s importance for skin formation, vitamin C is highly recommended to fight wrinkles, dryness and loosening, which promote long term skin health, beauty, and anti-aging purpose.
5. Treatment of the common cold
Vitamin C is effective at treating colds, only if you take a substantial amount. Researchers concluded that taking in high dose (1,000mg to 4,000mg) can reduce cold duration and symptoms, also prevent the risk of developing further complications such as pneumonia and lung infections.
However, excessive amount of vitamin C can cause negative effects like diarrhea and gastrointestinal distress. It’s better to check with your physician to see if taking high dose (2,000+ mg) is right for you.
The most recent RDA has been calculated at 90mg for daily intake. Many researchers believe this amount is too low; it was calculated from depletion-repletion study data which is to prevent deficiency disease like scurvy.
In the terms of bioavailability, the optimum intake for best health effects is somewhere around 500mg to 1,000mg daily for average adult. For people who already have existing conditions such as cancer, cardiovascular disease, cold or flu, bad life style and smoking, the intake amount is better to increase up to 1,500mg daily.
These doses cannot be reached from food and beverage consumption. Therefore, you must be certain that the supplements to take are high quality, bioavailable and free of additives.
Food sources of vitamin C
Fresh and raw food sources will provide your body with abundant source of nutrition, it is recommended to eat five or more servings of fruits and vegetables per day. Always eat them raw, or cook with minimal water to prevent nutrient depletion.
Foods contain high vitamin C: kiwi fruit, guava, orange, lemon, grapefruit, papaya, strawberries, spinach, broccoli, red pepper, parsley