Vitamin D status may contribute to serum insulin-like growth factor I concentrations in healthy subjects

Objective: The aim of the study was to evaluate whether vitamin D[25-(OH) D(3)] status affects serum IGF-I concentrations in healthy subjects. Design and patients: Two hundred and forty-one consecutive healthy subjects were included in the present study. Measurements: Serum IGF-I and 25-(OH) D(3) concentrations. Results: As expected, serum IGF-I concentrations progressively decreased with age (r=-0.55, p<0.0001); on the contrary, gender was not related to serum IGF-I levels. A positive relationship was identified between serum 25-(OH) D(3) and IGF-I concentrations (r=0.33, p<0.0001); the 25-(OH) D(3)-dependent changes of serum IGF-I concentrations were observed also when subjects were divided on the basis of vitamin D deficiency; in fact, those with severe 25-(OH) D(3) deficiency (<20 ng/ml) had lower (185 +/- 83 mu g/l) IGF-I values than those with mild-to absent 25-(OH) D(3) deficit (225 83 mu g/l, p=0.0004). Conclusions: 25-(OH) D(3) status may contribute to determine serum IGF-I levels in healthy population