The morning serum cortisol, C-reactive-protein (CRP) and vitamin D levels were measured in a group of 30 boys and girls 14-25 years old, to see if there were any correlations between Internet use and alteration of same hematochemical (blood chemistry) parameters. Based on a questionnaire about digital habits and lifestyle and a test related to the perceived stress scale (PSS), the sample was divided into two groups. The first group included the guys who didn’t fall within Internet abuse risk range, while the second one included those who fell within this risk range. In the first group only 2 subjects had high levels of cortisol and 6 of them had a vitamin D deficiency; while in the second group high levels of cortisol and very low levels of vitamin D were detected in 12 subjects. CRP levels were normal in both group except for a girl with a problem of relapsing otitis. Purpose of the study was to investigate which consequences on the health state Internet abuse could have among adolescents, through the evaluation of cortisol: indeed, the long-term repercussions of high levels of the main stress hormone on the brain and on the immune-system are known.
Keywords: Cortisol, Vitamin D, Internet, Adolescents, Stress, Immune system.