Vitamins in fruit and vegetables – Lexicon for medicine and health

Vitamins in fruits and vegetables

The vitamins – this has already been emphasized many times here at and in numerous other publications – are one of the most important groups of active ingredients in our food. Their importance lies in their irreplaceability for the metabolism and thus for the maintenance of health, indeed of life itself. The metabolic functions of the human body are extremely diverse. Some of them are required for the construction of numerous ferments, others for the production of hormones, and others, thanks to their special chemical activity, can serve as carriers of oxygen and hydrogen and thus intervene in many metabolic processes.

Without vitamins we become weak and sick

Without a doubt, the metabolism of the human organism is able to evade, so to speak, improvising if one or the other vitamin is too scarce.

However, there are limits to these possibilities, after which clear signs of failure appear, which can be of a general nature and become noticeable as discomfort, a drop in performance , a functional failure of the nervous system or a weakness in the defense against infections .

In other cases, very specific symptoms occur, such as bleeding gums , tears in the mucous membrane at the corners of the mouth, certain skin rashes , edema formation, cardiovascular weakness or other signs of deficiency.

In any case, it can be said that those who are poor in vitamins are below their constitutional top form and suffer a loss of well-being and performance. In decades of research, it has been possible to determine the minimum quantities required to maintain health and the best level of supply for many vitamins.

This made it possible to work out vitamin balances for individual people or larger population groups. Such calculations showed that by no means all people meet their real vitamin needs. As these group studies have shown, there are often underbalances in the case of some vitamins.

There is almost talk of a characteristic malnutrition situation in the European industrialized countries, where, in addition to an oversupply of fat, there are clear deficiencies in vitamins C , E and several B vitamins , and not infrequently vitamin A as well .

Balanced vitamin balance & vitamin balance

The vitamin balance is now subject to significant seasonal fluctuations in the temperate and northern parts of the world. The most critical season in this respect is spring for several reasons. On the one hand, our stored staple foods suffer more or less large vitamin losses during storage.

This applies above all to potatoes, winter fruit and perennial vegetables. Then, for climatic reasons, the supply of vitamin-rich fresh food is significantly lower in the first spring than in summer and autumn. In the case of some animal foods, winter feeding with fewer vitamins has an effect on the vitamin content of these products, such as milk, eggs and meat.

As a result of the interaction of the factors mentioned, some people who eat an adequate diet with all active ingredients in the summer fall into a vitamin deficiency during the first spring months , with a corresponding impairment of health and performance.

The view is held with a certain right that, in addition to meteorological influences, the lack of vitamins in the spring diet is to be regarded as the cause of the widespread “spring fatigue” – with a certain right because a number of other factors are also responsible for it.

While the vitamins of the B group, which are predominant in cereals, and vitamin E suffer only a relatively small loss during the winter storage of the grain, the seasonal losses of vitamins C and A found in other foods are far more remarkable.

Particular attention should be paid to adequate intake of vitamin C in particular, since this vitamin can only be stored to a small extent by the human body, so we are dependent on constant intake. Unfortunately, it is not possible to ensure that you get through the winter “well” just by eating a lot of fruit and vegetables during the summer.

Daily requirement of vitamins

The daily requirement of an adult for vitamin C is assumed to be 75 mg, and that for vitamin A or its precursor carotene is 2 to 3 mg. Those suffering from infections as well as pregnant and breastfeeding women need 30 to 100 percent more.

Vitamin supply can be secured in spring if the vitamin losses are reduced to a minimum through the correct handling of the food and, on the other hand, care is taken to carefully select the foods based on their vitamin content. Incorrect storage and preparation can cause very significant losses, especially with the easily destructible vitamin C. It can even be completely destroyed if it is not prepared properly.

Vitamin C is particularly sensitive to oxygen, contact with active metals such as copper, iron , and zinc , heating upon exposure to air, leaching, and exposure to baking soda and baking soda. The vitamin A content is reduced in particular by exposure to light, atmospheric oxygen, temperatures above 100 degrees and rancidity of the fats.

According to the usual eating habits in Germany, a considerable part of the normal vitamin C requirement can be covered by potatoes alone. The vitamin C content of potatoes shows a clear downward trend during winter storage: 100 g of fresh potatoes contain 28 mg in July-September, October 18, December 13, January 11, March 9 and April 8 mg.

However, the potato can only provide a larger proportion of our vitamin C requirement if it is treated with care and prepared sensibly. The smallest storage losses occur at storage temperatures of around 1-4 degrees. When preparing the potatoes, it is important to eliminate all avoidable sources of loss. In detail, it should therefore be noted that the losses due to leaching are already 50 to 60 percent if potatoes are peeled the day before and kept under water.

Preservation of vitamins in cooking

The gentlest cooking methods are steaming peeled potatoes and simmering peeled potatoes. The potatoes, which have been boiled briefly with a little water, are kept at a temperature of between 75 and 95 degrees until they are done. Cooking in an open pot leads to significantly greater vitamin losses than cooking in a covered saucepan.

When you keep cooked potatoes warm on the stovetop or in the oven, the vitamin C content drops quickly. After 2 to 3 hours, the content is barely half of what it was when it was cooked. If the kitchen is used sensibly, around 40 percent of the required amount of vitamin C can also be ingested in the spring through daily potato dishes. If the cooking process is incorrect, the potato will be eaten practically free of vitamins.

Appropriate caution is also required when processing fresh vegetables and fruit. With all varieties suitable for this purpose, it is also important to note that the preparation of fresh salads is much more vitamin-friendly than any form of cooking. Raw vegetable salads made from leaf, tuber and root vegetables should therefore be widely used as a starter or side dish, especially in spring.

The vitamin content of steamed vegetables can be improved by adding an appropriately chopped, raw portion, which is added just before serving. With spinach, white cabbage, sauerkraut and Chinese cabbage, carrots and other vegetables, about 20 to 25 percent of the total amount can be added raw, which can improve the taste significantly.

Frozen products are becoming increasingly important for vitamin supply. With the help of the vitamin-preserving deep-freezing process, it is possible to compensate for seasonal supply gaps. The retention of value in the frozen vegetables and fruits at the required temperature of -18 to -22 degrees is pleasingly stable, but the vitamin content drops just as quickly when they are thawed.

Defrosting starts at -8 degrees, so the most important rule is to store these products evenly at temperatures of -18 to -22 degrees and to keep the critical defrosting time before consumption as short as possible. If no freezers are available, frozen products should therefore not be bought in advance.

Frozen vegetables are placed in the cooking pot in a frozen state and stewed or steamed like fresh vegetables. The time required for steaming is slightly shorter than with fresh vegetables. Only spinach and kale are unwrapped, thawed at kitchen temperatures for about 2 hours until the crust is softened, and then sautéed with oil in the usual manner. Frozen fruit should only be eaten when completely defrosted. Fruits frozen with dry sugar need 3 to 5 hours at kitchen temperature, fruits processed in sugar solution 6 to 8 hours.

Vitamins in milk

Another staple food, milk, has a very varied, but individually highly variable vitamin content . Before the beginning of spring, the amount of vitamins is lower than in summer, so we have little to rely on this source of vitamins.

In the treatment of milk in the household, the hygienic requirements of infection prevention compete to a certain extent with the aspects of vitamin conservation. Milk reaches the consumer after being pasteurized 1 to 3 times. You should avoid reheating bottled milk or milk in beverage cartons that is perfectly sealed, as this is always associated with additional losses of active ingredient.

Much more than in summer and autumn, when we draw many vitamins from the abundance, in the spring there is room for consideration when choosing food. In the following, some foods are listed that contain plenty of one of the two vitamins A and C, which are particularly relevant in spring, and should therefore be preferred. The values ​​given refer to 100 g of fresh fruit or vegetables.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.