NAD Augmentation to Prevent or Reverse Alzheimer's Disease in People With Down Syndrome

1. A diagnosis of full trisomy for chromosome 21 or complete unbalanced translocation of chromosome 21, confirmed by karyotype analysis or clinical documentation.

2. 18 years or older

3. Participant has a caregiver/ informant who has direct contact with the participant >10 hours/ week and who can provide information about participant's health

4. Participant or Legal Authorized Representative is able to understand and willing to provide written informed consent and capable of completing study assessments.

5. In addition, female participants must Not be pregnant and not planning to become pregnant over the next 6 months

1. Fasting morning UACR > 5,000 mg/ g creatinine

2. Other laboratory abnormalities:

1. Has AST or ALT > 3 times the upper limit of normal

2. eGFR < 30 mL/ min / 1.73 m2

3. Hematocrit < 0.34 or > 0.50 L/L

3. A major adverse cardiovascular event in preceding 3 months

4. Participation in an investigational trial to evaluate pharmaceuticals or biologics within the past 3 months or 5 half-lives, whichever is shorter

5. Current alcohol or substance use disorder or dependence (DSM 5 criteria).

6. Major depressive disorder, bipolar disorder, schizophrenia, or current psychotic symptoms or behavioral problems that could interfere with study procedures.

7. An acute illness, including COVID-19, requiring hospitalization within the past 3 months or any acute illness, including COVID-19, within the past month.

8. Has a history of anaphylaxis from vitamin B3 derivatives

9. BMI > 42.5 kg/ m2

10. Non-ambulatory