Youth and long-term dietary calcium intake with risk of impaired glucose metabolism and type 2 diabetes in adulthood.

Context: No previous studies have examined the role of youth calcium intake in the development of impaired glucose metabolism, particularly those with long-term high calcium intake.

Objectives: To examine whether youth and long-term (between youth and adulthood) dietary calcium intake is associated with adult impaired glucose metabolism and T2D.

Design, Setting, and Participants: The Cardiovascular Risk in Young Finns Study (YFS) is a 31-year prospective cohort study (n=1134, aged 3-18 years at baseline).

Exposures: Dietary calcium intake was assessed at baseline (1980) and adult follow-ups (2001, 2007 and 2011). Long-term (mean between youth and adulthood) dietary calcium intake was calculated.

Main outcome measures: Adult impaired fasting glucose (IFG) and T2D.

Results: We found no evidence for non-linear associations between calcium intake with IFG or T2D among females and males (all p for non-linearity>0.05). Higher youth and long-term dietary calcium intake was not associated with the risk of IFG or T2D among females or males after adjustment for confounders including youth and adult BMI.

Conclusions: Youth or long-term dietary calcium intake is not associated with adult risk of developing impaired glucose metabolism or T2D.