Vitamin C or ascorbic acid is an organic acid or more correctly an acid anhydrite. This is because in pure form the substance is a white crystalline solid. Only when dissolved in an aqueous environment does the acidic reaction occur. Compared to other vitamins, ascorbic acid is a relatively simple (low molecular weight) compound. Many mammals can produce vitamin C themselves, but humans are unable to do so and must obtain this vital nutrient from food.
Vitamin C reacts chemically as a strong antioxidant. This is also the basis for some of its physiological functions. For example, ascorbic acid is known to render toxic substances harmless. With the keyword “radical scavenger”, the Nobel Prize winner Linus Pauling recommended the intake of high doses of vitamin C for cancer prophylaxis. Free radicals are unstable and therefore aggressive substances that enter the body as environmental toxins (air pollution, smoking) or with food (frying, grilling).
In addition, ascorbic acid fulfills a number of other important functions in the body. For example, its protective function, which helps prevent colds, is well known. Vitamin C also plays an important role in the provision of metabolic energy and is thus an essential factor in our vitality. Ascorbic acid is also functionally involved in the synthesis of proteins, which is particularly expressed in the formation of connective tissue. Essential is also the activity of the vitamin in the biochemistry of cholesterol: The organism can break down this “steroid” into bile acids only with the help of ascorbic acid. Steroids are also the precursors of some hormones, to whose physiological balance vitamin C contributes. The versatility of ascorbic acid is already evident during the digestive process: in the intestine, the vital substance promotes the absorption of iron and zinc.
The diverse functions are countered by a whole series of deficiency symptoms if the daily intake of about 100 mg (one milligram corresponds to 1/1 000 gram) is drastically undercut. The symptoms of such hypovitaminosis are summarized under the term “scurvy”. Before the correlations were known, scurvy was mainly an affliction of sailors who received inadequate food rations. The first sign of scurvy is bleeding of the gums, a process that can progress to tooth loss. Inflammation of the joints and muscle atrophy are further consequences. Weakness of the connective tissue means that wounds can hardly heal. Fever episodes result from an increasing susceptibility to infectious diseases.
Citrus fruits in particular are considered a good source of vitamin C. However, their content of about 50 mg/100g is not yet a peak value and is thus not higher than that of our cabbage varieties. In acerola cherries, the concentration of ascorbic acid is up to 1 800 mg per 100g fresh weight. Domestic fruits with high content of vitamin C are currants (200 mg/100g), fresh sea buckthorn berries(500mg/100g), but especially rose hips (1300 mg/100g). Among vegetables, raw bell bell pepper is recommended, which contains 150 mg/100g of vitamin C.
It should be taken into account that ascorbic acid is not heat stable. Thus, the valuable vitamin is largely lost during cooking. Who would like to supply itself sufficiently with Vitamin C, should pay attention to sufficient raw food. Furthermore, it should be noted that there are dietary supplements in the form of capsules and tablets that contain appropriate doses of ascorbic acid.