Vitamins
Vitamins are molecules essential for life; these are micronutrients to be taken in very small quantities, especially when compared to energetic macronutrients;
the amount of vitamins to be introduced daily with the diet, although specific and variable, in fact oscillates between micrograms (µg) and milligrams (mg).NB. Both deficiency (hypovitaminosis or avitaminosis) and excess (hypervitaminosis) can be harmful to health.
Sensitivity to light
Vitamins can be classified by several methods; the most common are undoubtedly the association with a letter of the alphabet (frequently misunderstood as a noun that names the vitamin in question) and solubility (in water or fatty acids - fat-soluble or water-soluble). However, the chemical-physical characteristics there are many vitamins and each of them can represent a good classification criterion; they are a typical example thermolability and the pH sensitivity. In the following paragraph an aspect of vitamins (in my opinion) less known than the previous ones will be analyzed: the slight sensitivity or photosensitivity.
The reader may ask: Why should light sensitivity be of nutritional concern?
The answer is quite simple; sensitivity to light represents a characteristic that affects (relatively) the functional integrity of vitamins in food; in other words, the photosensitive vitamins that are exposed to light may not "survive" in necessary quantities. Obviously, consume mainly foods with most of the vitamins degraded by light are not a good nutritional habit.
Photosensitive vitamins
For convenience, in the description of the photosensitive vitamins, the various molecules can be cited with their equivalent in the letter of the alphabet; moreover, for reasons of methodological correctness, they will also be subdivided by solubility.