Discovered more than a century ago (Casimir Funk, 1911), vitamins are now recognized as essential nutrients for maintaining good overall health.
Vitamins are essential molecules in small amounts, although the amounts needed by individuals vary depending on their health, lifestyle, and sources of nutrition. Vitamins are necessary for growth the structural integrity of cells and the smooth running of metabolic processes.
Some common properties of vitamins
From a chemical point of view, vitamins are very different organic substances but with some characteristics in common, for example:
- If they are essential, our bodies cannot to produce them (except vitamin K and partly vitamin D).
- They have no energy value, but their presence allows the biological reactions that release energy.
- They are needed in minimal doses, in milligrams or micrograms.
- They have specificity of action: each plays a highly specialized role in the organism.
Water-soluble and fat-soluble vitamins: what differences?
Vitamins are divided into two large groups:
- Water-soluble vitamins (Vitamin C and B vitamins, Vitamins H and PP): to be taken every day through the diet as they don’t accumulate in the body. They dissolve quickly in the cooking water if the food is boiled. Water-soluble vitamins are susceptible to heat, pH, the effects of prolonged storage and direct light. They are eliminated in urine.
- Fat-soluble vitamins (Vitamins A-D-E-K): are generally, more stable (except for vitamin A which is quite sensitive); they are absorbed with dietary fats, and follow the same digestive path. They are metabolized more slowly than water-soluble vitamins and can accumulate in the fats of various organs and tissues, especially in the liver and adipose (fat) tissue.
The main functions of vitamins
Although each vitamin performs its specific activities, three general functions can be ascribed to vitamins as a group of nutrients.
- Function of control, as indispensable coenzyme partners, of energy metabolism.
The synergistic action of vitamins and energy allows each reaction to proceed smoothly. Without the specific vitamin, essential reactions cannot occur, and the metabolic process cannot proceed normally.
- Support function in the construction and tissue repair of the organism
Some vitamins promote the construction of body tissues. For example, vitamin C helps the formation of connective tissue in intercellular spaces, thus performing a cementing action between one cell and another.
- Antioxidant function
Recent research highlights the antioxidant action carried out by some vitamins such as Vitamin E, C and beta-carotene, a precursor of vitamin A. Acting in synergy, these vitamins neutralize dangerous free radicals which are highly unstable reactive molecules produced during human metabolism and play a fundamental role in accelerating the aging process and in the development of various diseases.
Main functions, vitamin for vitamin
| VITAMINS | Main function |
| WATER-SOLUBLE | |
| Thiamine (B1) | It intervenes in different enzymatic reactions in carbohydrate metabolism. Promotes the correct activity of the nervous system and digestive system. |
| Riboflavin (B2) | Necessary for the production of energy by carbohydrates and fats. Important for the state of nutrition of the skin and mucous membranes. |
| Vitamin PP (niacin or B3) | Important as it takes part in cellular respiration reactions of synthesis and demolition of amino acids, fatty acids, and cholesterol. |
| Pantothenic acid (B5) | It constitutes Coenzyme A (CoA), involved in numerous fundamental metabolic reactions. It is of considerable importance to allow healthy growth and production of hormones and antibodies. |
| Pyridoxine (B6) | Mainly involved in protein metabolism, it preserves the nervous system, skin, muscles, and blood. It plays a role in hemoglobin synthesis and antibody production. |
| Vitamin H (biotin or B7) | It is s co-enzymatic in metabolizing carbohydrates, lipids, proteins, and nucleic acids. important for the health of skin, hair and nails |
| Folic acid (B9) | Essential for cell development and reproduction. It is essential for the synthesis of nucleic acids, the metabolism of amino acids, the transmission of nerve impulses, the production of red blood cells and to maintain healthy skin. Its action is related to that of vitamin B12. It is essential for pregnant women as it promotes the formation of the fetus’s nervous system. |
| Cobalamin (B12) | It is characterized by a cobalt atom at the center of the molecule, an element from which it takes its name. It is absorbed in the intestine and requires the presence of a protein secreted by the stomach, the congenital lack of which gives rise to a form of anemia. Essential for the production of red blood cells. Folic acid it is indispensable for cell renewal and growth. |
| Vitamin C (ascorbic acid) | It facilitates iron absorption, contributes to the production of red blood cells, strengthens blood vessels, helps wound healing, and maintains healthy teeth and gums. It intervenes in the metabolism of collagen, the most abundant structural protein in the human body, in the metabolism of iron and fats, and synthesizing hormones of the adrenal glands and bile acids. It strengthens the immune system and promotes the detoxifying action of the liver. It has an important antioxidant action, which is why it is also used as a food additive. |
| VITAMINS FAT-SOLUBLE | |
| Vitamin A (retinol) | It is involved in the mechanism of vision as it constitutes the visual pigment found in the retina. It is also essential to maintain intact epithelia and mucous membranes, for the growth of the body and the functionality of the reproductive system. Finally, it strengthens the immune system and prevents the formation of tumors. |
| Vitamin D (calciferol) | It regulates calcium metabolism favoring the correct mineralization of the skeleton and teeth. It is essential for the intestinal absorption of calcium and to maintain a constant level in the blood (calcemic). |
| Vitamin E (tocopherol) | It performs a powerful antioxidant action and fights free radicals that can damage tissues. It protects cell membranes from oxidation, delaying their deterioration and thus preventing premature aging of the body. It is used as an additive in products that contain fat. It is important for the heart, circulation, nerves, muscles, and red blood cells. |
| Vitamin K (phylloquinone) | It plays a vital role in the process of blood clotting. In addition, it works, together with vitamin D, in calcium metabolism. |