Summary The primary aim of this 90-day randomized trial in older adults with Alzheimer's Disease and mild dementia will determine whether nicotinamide mononucleotide (NMN), a NAD+ precursor, crosses the blood-brain barrier, and engages the hypothesized target mechanism. We hypothesize that βNMN administration will cross the blood-brain barrier and increase brain NAD+ concentrations. This application for administrative supplement requests funds to support the addition of a second clinical trial site to expedite participant recruitment and enable the completion of the trial and accomplishment of the proposed aims of the project. This request for supplemental funds was necessitated by the delay in trial's completion due to multiple unanticipated factors that included: 1) longer than expected time for securing Food and Drug Administration's approval of the IND; 2) longer than expected time for IRB review of the study protocol; 3) unanticipated mechanical problems with the head coil required for the 7T magnetic resonance spectroscopy which delayed trial's initiation; 4) reluctance of the many participants to undergo lumbar puncture for the collection of the cerebrospinal fluid; 5) participants excluded because of ineligibility for lumbar puncture or 7T MRS; 6) a large number of competing AD trials in the Boston metropolitan area; and 7) in the wake of the COVID pandemic, many older adults, especially those with AD, have been reluctant to come into a healthcare facility for research studies. To overcome these barriers and expedite enrollment, we have made several changes in the study protocol with the approval of the DSMB, IRB, and program staff; added a recruiter at BWH; and plan to add a second trial site at Beth Israel Deaconess Medical Center (BIDMC) under the leadership of Dr. Daniel Press, an NIH-funded investigator and cognitive neurologist with expertise in conducting AD clinical trials. We plan to continue to randomize an average of 1 participant each month at the BWH site and will have enrolled an additional 9 participants at the BWH site. The BIDMC site also will enroll one participant per month for a total of 8 subjects over the next 8 months. This should enable us to complete the enrollment by August 31, 2024, with the last participant completing the intervention by November 30, 2024. The data clean-up, data-lock, analyses and preparation of the primary manuscript will take an additional 4 months. We will request a no cost extension for one year. We are requesting supplemental funds to support the trial activities at BIDMC site and a nominal additional effort (7.5%) for the Project Manager for project coordination and additional administrative and reporting tasks. This planned addition of a second trial site has been discussed and approved by the trial's DSMB and the program staff. The cost saving associated with fewer laboratory tests, procedures, and subject payments due to fewer subjects having been enrolled will be carried forward to s...