Vitamins are vital ingredients of the food. They do not provide energy but are indispensable for many metabolic processes.
Vitamins are organic substances that the organism needs for certain vital functions, but can not, or only in insufficient quantities, produce itself. Vitamins are thus essential, i. they must be ingested regularly with food. The daily requirement for these micronutrients is low compared to the required amounts of energy-supplying nutrients.
Provitamins are vitamin precursors, which are only converted into the active vitamin in the body.
Requirements and quantity recommendation:
The need for vitamins depends on the individual, his physical and psychological condition (eg illnesses, stress). The information for adequate vitamin intake should take into account: age, gender, level of performance, health status, dietary composition, etc.
The indicated desirable daily intake levels contain a safety margin that exceeds the requirement. The indicated quantities do not have to be recorded daily. On average, however, the supply should correspond to these quantities.
As critical vitamins, i. Vitamins, which are often below the recommended intake, are the vitamins B1, B2, B6 and folic acid in Germany. To detect possible deficiencies in the supply of vitamins, nutrient recommendations are issued, which apply to about 97% of the population.
As you can see in the sometimes very different intake recommendations for vitamins and minerals, there is still no certainty about what quantities the human body needs exactly. The individual needs may vary. For some vitamins, different values apply for women and men, as well as for pregnant and breastfeeding women. Age also influences the nutritional requirements as well as diseases or special burdens.
There are two groups of vitamins:
- Fat-soluble vitamins:
Vitamins A, D, E and K are included in the group of fat-soluble vitamins. The absorption of fat-soluble vitamins is done together with dietary fats. Excessive vitamins of this group are stored in the body. Man can get by these supplies after a regular and sufficient supply for some time with less intake quantities. The body can only excrete small amounts of these vitamins via the intestine. As a result, overdose is possible. Beware of self-medication!
- Water-soluble vitamins:
Vitamin C and the Vitamin B Complex (Vitamin B1, B2, B6, B12, Niacin (PP), Pantothenic Acid (Coenzyme A), Folic Acid (M), Biotin (H), Rutin (P), Ortoic Acid (B13), Pangametine (B15)) are water-soluble vitamins. Water-soluble vitamins can only be stored in small quantities. The body’s storage capacity for these vitamins varies greatly: Vitamin B1: 1-2 weeks, B2, B6, C, and niacin: 2-6 weeks, folic acid: 3-4 months, B12: 3-5 years. [Lit-1] Therefore, they must be supplied to the body regularly in sufficient quantity. Surpluses are excreted via the kidneys (urine). Overdoses are still possible.