Investigations of the Optimum Serum Bicarbonate Level in Renal Disease.

Inclusion Criteria: * Veteran * Age older than 18 years * Diabetes mellitus * Serum bicarbonate 22 - 28 mmol/L on the most recent measurement within the past six months * Stage 2, 3, or 4 CKD (defined as estimated glomerular filtration rate (eGFR) 15 - 89 ml/min/1.73m2 using the CKD-Epidemiology equation) * Urinary albumin:creatinine ratio \> 30 mg/gm on the most recent sample within the past 12 months. Exclusion Criteria: * Lean body weight \> 100 kg * Use of oral medications typically prescribed to raise low serum bicarbonate levels (i.e. sodium bicarbonate, sodium citrate, potassium citrate). * Serum potassium \< 3.5 meq/L at enrollment visit * Use of 5 or more antihypertensive agents, regardless of the indications of each agent * Systolic blood pressure \> 140 mmHg or diastolic blood pressure \> 90 mmHg at the enrollment or baseline visit * Diagnosis of congestive heart failure with current, active Class III or IV New York Heart Association symptoms. * Significant fluid overload such that it is unsafe in the opinion of the PI for the patient to participate in the trial * chronic gastrointestinal disorder or any other factors judged to be likely to limit adherence to interventions (i.e. alcoholism, a history of missing clinic visits) * Chronic immunosuppressive therapy for transplanted organs or other indications * Individuals who are currently a member of a vulnerable population (I.e. incarcerated, pregnant). 11.Currently participating in another interventional research study