In the age of technology, most human diseases are getting younger. The role of vitamin D insufficiency and deficiency in the development of modern diseases cannot be denied. In developed countries, the importance of this vitamin in the human body has been carefully studied, but over the past 20 years we have known that this «vitamin» acts only on the musculoskeletal system. According to recent reports, ½ people in the world are deficient in vitamin «D». In particular, 90% of the population of Kazakhstan suffers from various diseases due to insufficiency or deficiency of vitamin «D». One of the reasons why in particular people in the northern regions are deficient in vitamin «D» is the low level of ultraviolet rays per year due to the relatively long winter period. Secondly, the style of work is changing: a significant part of the work of the last century, which was performed by workers in open fields under the sun, was replaced by automated equipment, and people began to work in offices. This article summarizes the ratio of various diseases caused by vitamin D insufficiency and deficiency in the body and reflects recent statistics of vitamin D insufficiency and deficiency in Petropavlovsk.