Vitamin C – or ascorbic acid – is a water soluble vitamin which is also known as the antiscorbutic vitamin.
Which foods contain the vitamin?
- Rose hip
- Bell pepper
The vitamin’s biofunctions
Ascorbic acid is essential for the normal functioning of the skin, gums, capillaries, teeth, ligaments, and bones. The normal development of ligaments and the healing of wounds is ensured by the coenzymatic role of vitamin C as it is, for instance, the coenzyme for prolin hydroxylase and lysin aminoxidase, with the latter ensuring the normal synthesis of collagen.
Ascorbic acid is also essential in several hydroxylation processes, such as the synthesis of mediators like serotonin, adrenaline, and noradrenaline, as well as carnitine and several steroids.
Vitamin C is also an important antioxidant which prevents the oxidation of haemoglobin, eliminates the free radicals of vitamin E, and prevents the oxidation of vitamin A, riboflavin, folic acid, thiamine, and pantothenic acid.
Vitamin C is also important for participating in the biotransformation of medicines and in strengthening the immune system. It promotes the absorption of Fe2+ and the development of the coenzyme form of folic acid.
Absorption, retention, and excretion
Although absorption of the vitamin starts in the mouth and stomach, the largest quantity of it is absorbed in the small intestine through diffusion. It is important to make it clear that absorption is inhibited by alcohol, smoking, oxidative stress, fever, aspirin, paracetamol, cortisone, sulphonamide, barbiturate, baking soda, antihistaminic preparations, and oestrogen.
The level of ascorbic acid is achieved between two and three hours after administration and, in blood, vitamin C is free and protein-bound.
Excessive ascorbic acid is excreted from the organism via urine within a period of between three to four hours, and this process is accelerated by sulphonamides and other medications which contain sulphur. The consumption of large quantities of excessive water, however, lowers the stocks of vitamin C in the organism.
Problems related to deficiency
Deficiency is rare because the compound is very common in plant-based materials.
The symptoms of any deficit are as follows:
- pale gums
- aching joints
- slow recovery of injuries and bone fractures
- blue spots on the body
- Severe deficiency results in scurvy, oedema, bleeding and inflammatory gums, slowly improving wounds, easily fractured bones, and diarrhoea.
Risk groups for deficiencies
- Excessive users of antibiotics
Excessive consumption results in disorders which relate to the functioning of the digestive system, such as diarrhoea, vomiting, oxalate kidney stones, hot flashes, fatigue, and nausea. Constant consumption of large doses makes it difficult to determine the level of glucose in blood or urine because vitamin C and its metabolites interfere with the methods that are used for determining glucose levels.
The use of vitamin preparations
The need is increased for smokers who should use between one and two times more vitamin C than the usual norm, and also for women during menstruation.
The use of ascorbic acid as an additional treatment component can be efficient when treating alcoholism, arthritis, beriberi, oxidative stress, back pain, teeth and gum diseases, and also eczema, psoriasis, acne, muscular dystrophy, bronchitis, rheumatism, haemorrhoids, atherosclerosis, osteoporosis, and prostatitis.
It is important to use ascorbic acid together with folic acid, pyridoxine, niacin, thiamine, riboflavin, vitamin E, bioflavanoids, calcium, and magnesium.
Figure 1. Vitamin C: ascorbic acid
Vitamin C content in food
Quantities of food that need to be eaten to obtain the recommended daily dose of vitamin C.
|Blackcurrant||19 g||25 g||30 g||36 g||36 g||44 g||–|
|Rose hio||15 g||20 g||24 g||28 g||28 g||35 g||–|
|Bell pepper||19 g||25 g||30 g||36 g||36 g||44 g||–|
|Kale||85 g||110 g||134 g||159 g||159 g||195 g||–|
|Horseradish||33 g||43 g||52 g||62 g||62 g||76 g||–|
|Parsley||26 g||34 g||41 g||49 g||49 g||60 g||–|
|Blackcurrant||32 g||44 g||44 g|
|Rose hip||25 g||35 g||35 g|
|Bell pepper||32 g||44 g||44 g|
|Kale||142 g||195 g||195 g|
|Horseradish||55 g||76 g||76 g|
|Parsley||44 g||60 g||60 g|