In the CDs rat model, beta-cell dysfunction and pancreatic exocrine damage are triggered and prevented by altering dietary Cu content suggesting a chronic and acute role for Cu. These abnormalities become apparent when the CDs rats are exposed to high sucrose low copper diet, triggering a vicious sequence of events: exocrine damage, recruitment of macrophages expressing IL-1beta leading to oxidative stress and even more reduction in the activity of Cu-dependent enzymes (chronic effect). When Cu levels are re-established (acute effect) they may prevent the inhibitory effect of IL-1beta on insulin release and may restore the activity of enzymes inhibited by IL-1beta. In this study we will identify humans with marginal Cu status that may benefit from copper supplementation to normalize their GSIS. These patients will be given a daily Cu supplement (3mg/d), or placebo for a period of 6 months. GSIS, pancreatic dysfunction and biomarkers of marginal Cu status will be measured in different blood components before and every 4 weeks during treatments or placebo.

Inclusion Criteria:

• diabetic subjects with BMI < 33
• HbA1C < 8
• plasma copper levels of < 90 ul/dl

Exclusion Criteria:

• patients with bad physical conditions