Melanocyte concentration in the skin is similar in all people, yet melanocyte activity varies depending on ethnic origin. Furthermore, the frequency of ultraviolet ray exposure greatly affects melanine production. This is greater in people who are often exposed to the sun than in people whose exposure to the sun is less frequent. A less known fact is that using sun creams with a high protection factor can block or slow down melanine production and thus hinder the skin’s natural protection process. The higher the factor, the longer the required sun exposure to activate the natural protection process. Furthermore, a high protection factor will prevent some biologocal processes, e.g. vitamin D production.