Vitamin D3 is produced in the dermis (deep layer of the skin) through the stimulation of UVB radiation. To a lesser extent, it can also be obtained through diet, with animal products such as oily fish.
It is known to play a regulatory role in bone maintenance (calcium and phosphorus content that form the skeleton), and on the immune and endocrine systems. Severe deficiency during childhood can lead to severe damage (rickets). This is why vitamin D supplementation is often given to infants, who should not be exposed to the sun during their first year, under paediatric supervision.
In adolescents and adults, moderate sun exposure (15 minutes per day) can cover vitamin D production needs. In the case of dark phototypes or certain diseases, these needs may not be sufficiently covered. To consider supplementation, it is advisable to consult a healthcare professional.