by Dr. Emanuele Rondina, nutrition biologist in Bologna

 

Winter is the season in which we are most exposed to a lowering of the immune system. Temperature changes, work stress, and bad eating habits (with abuse of foods rich in sugars and fats), in fact, negatively affect our well-being.

 

 

 

Why are vitamins important, especially in winter?

Firstly, a correct and balanced diet, with regular physical activity, is essential to stay healthy. These habits can strengthen our immune system and protect the body from illness.

 

In particular, some foods contain many antioxidants capable of fighting free radicals, which weaken the immune system, and a very high content of vitamins, which perform fundamental functions for the proper functioning of our body.

 

In addition to vitamins, polyphenols - pigments of plant origin - also provide specific protective action at the cellular level. They are effective antioxidants with anti-inflammatory, antiallergic, and antiviral properties. Among the main polyphenols are quercetin, epicatechin, flavonoids, anthocyanidins and anthocyanins.

 

Fruit and vegetables, rich in vitamins, are also a precious source of polyphenols and should never be missing in the daily diet. Citrus fruits, such as lemons, oranges, tangerines, and grapefruits, are winter fruits rich in Vitamin C and polyphenols, allies of health and well-being.

 

 

 

Vitamins that help us better cope with flu symptoms and support the immune system

Vitamins are essential elements for the well-being and health of the body. In particular, given the winter season, we can count on some specific vitamins, which support our immune system at various levels and allow the body to exercise its functions to the fullest.

 

Vitamin C is essential: ascorbic acid participates in the inactivation of oxygen free radicals, which ensures protection from oxidizing agents, which are toxic to the cell. In fact, the link between high levels of oxidative stress and immune deficiencies is now clear.

 

Fat-soluble B Vitamins are essential molecules for the functioning of our cells, as they play a primary role in energy metabolism, which provides fuel for cells, enabling them to breathe and reproduce. They are coenzymes of various proteins and catalyze oxidation-reduction reactions essential for cellular respiratory processes. They are found in brewer's yeast, lean meats, fish, legumes, and oil seeds.

 

Vitamin D: the various functions of vitamin D include intervening in the proper functioning of the immune system.

 

 

 

Vitamin D and immune support in the winter months

Recent studies have shown that the active form of vitamin D contributes to more efficient upper respiratory tract defenses by helping to increase the production of antimicrobial peptides

 

In particular, the activation of Vitamin D3 determines the production of a bactericidal protein, cathelicidin LL-35, and paracrine functions of modulation of T and B lymphocytes.

 

The sun enables us to form 90% of vitamin D through the biochemical reaction that occurs in our skin between UV radiation and dehydrocholesterol (a molecule in the skin derived from cholesterol). Vitamin D is not formed immediately. The first molecule resulting from the reaction between dehydrocholesterol and UV radiation is an intermediate, unstable compound called pre-vitamin D3. Within 48 hours, this intermediate molecule spontaneously converts into a thermodynamically more stable compound called Vitamin D3 or cholecalciferol.

 

Unfortunately, during winter, the lack of exposure to sunlight and the lower intensity of UV rays do not favor the production of vitamin D, which is so important for our body.

 

Vitamin D can also be absorbed through the consumption of some foods of animal origin (fish, crustaceans and mollusks, eggs, milk, and derivatives) that contain it in significant amounts or foods of plant origin (e.g. mushrooms) where it is found as vitamin D2 or ergocalciferol. In both cases, absorption primarily occurs in the small intestine, where dysbiosis, a common condition, can further hinder it.

 

 

 

How to take vitamins

Given the importance of vitamins, the World Health Organization (WHO) recommends eating at least 400 grams of fruit and vegetables, the primary source of these substances, in five daily portions.

 

However, Vitamins, especially Vitamin C contained in food, are sensitive to degradation. Therefore, fresh fruit and vegetables should be eaten raw, without cooking them and keeping them away from light and heat.

 

If your doctor or nutritionist identifies deficiencies in specific vitamins, especially useful during the winter season, resorting to targeted supplements, preferably in a liposomal formulation, can improve the bioavailability and absorption of these important elements.