"Vitamin D og risiko for akutte luftveisinfeksjoner hos voksne friske"

Abstract

Most immune cells express vitamin D-receptor (VDR). In vitro trials show that vitamin D affects the function of immune cells. It is therefore possible that vitamin D affects immune function also in vivo. On this foundation the hypothesis that low serum levels of vitamin D affects the risk of acute respiratory tract infections has been posted. Observational studies consistently show that low serum levels of vitamin D are associated with an increased risk of acute respiratory infections. On the other hand the results from interventional studies that compare vitamin D intervention with placebo have been conflicting. However, these interventional studies have some limitations: relatively small study populations, low prevalence of vitamin D deficiency at baseline and suboptimal doses of vitamin D for intervention. Intervention studies including larger study populations with statistical strength to show possible effects also in subpopulations are therefore needed. The protocols in these studies should include doses of vitamin D sufficient to maintain adequate serum levels of vitamin D throughout the duration of the study and also maximizing the physiological effects of vitamin D.

Most immune cells express vitamin D-receptor (VDR). In vitro trials show that vitamin D affects the function of immune cells. It is therefore possible that vitamin D affects immune function also in vivo. On this foundation the hypothesis that low serum levels of vitamin D affects the risk of acute respiratory tract infections has been posted. Observational studies consistently show that low serum levels of vitamin D are associated with an increased risk of acute respiratory infections. On the other hand the results from interventional studies that compare vitamin D intervention with placebo have been conflicting. However, these interventional studies have some limitations: relatively small study populations, low prevalence of vitamin D deficiency at baseline and suboptimal doses of vitamin D for intervention. Intervention studies including larger study populations with statistical strength to show possible effects also in subpopulations are therefore needed. The protocols in these studies should include doses of vitamin D sufficient to maintain adequate serum levels of vitamin D throughout the duration of the study and also maximizing the physiological effects of vitamin D.