Vitamins are what are known as micronutrients: compounds that our body needs but cannot usually produce themselves, or only in insufficient quantities. Vitamin D occupies a special position because it can be formed by our body itself in interaction with the sun. Vitamins are involved in numerous metabolic processes in the body, help to build cells and hormones, function of enzymes, support the immune system and thus contribute to maintaining our health. The vitamin requirement varies from person to person and depends, among other things, on age, gender, special life situations, and weight There are 13 different vitamins: Some of them are fat-soluble and can be stored by the body for some time - mainly in the liver and the body's fat deposits. These include vitamins A, D, E, and K, which can only be absorbed by the body together with fat. With the exception of vitamin B12, water-soluble vitamins cannot be stored. It is therefore particularly important that they are supplied to the body daily through food.