The production of vitamin D-3 in the human body or otherwise "sun vitamin" is produced only photochemically and is done through skin exposure to sunlight and in particular UVB ultraviolet radiation. However, its production capacity varies.

Very often, light-colored individuals exhibit significant vitamin D-3 deficiency or deficiency due to the use of strong photo-protective creams or limited sun exposure in the morning and afternoon hours, in which UV rays A and to a minimum UVB. Dark people, who need a longer sun exposure time to produce adequate levels of vitamin D-3, have consistently low levels of vitamin D concentration. Additionally, older people are often D-3 sub-vitamin because they do not receive adequate exposure In the sun or are heavily malnourished.

Vitamin D-3 or cholecalciferol is an osteoprotective vitamin, which contributes significantly to the healthy growth and maintenance of bone, bone density as well as to the maintenance of blood calcium levels. This valuable vitamin determines immune system regulation, insulin secretion, actively contributes to healthy cell growth, possesses immunomodulating properties and supports the normal function of the nervous system.

Vitamin D-3 is contained in a few foods, mainly animal such as fish, liver and egg yolk. For those who have difficulty reaching the recommended levels through sun exposure and diet, taking a dietary supplement can help boost vitamin D-3 uptake.