Nicotinamide Riboside, Vit B3 Analogue, and Brain Energy Metabolism

The goal of this clinical trial is to learn how nicotinamide riboside (NR), a form of vitamin B3, affects brain energy metabolism in healthy adults. Researchers want to find out if taking NR by mouth for 2 weeks can raise the balance of two related brain chemicals called NAD+ and NADH, which play a key role in how cells make and use energy. The main questions are: Does short term NR treatment increase the NAD+ to NADH ratio in the brain, and does it change other brain energy measures that we can see with a special type of MRI scan called phosphorus 31 MR spectroscopy. Adults between 18 and 65 years old who are generally healthy and do not have a personal or close family history of mood or psychotic disorders may be able to take part. People who join the study will first have a screening visit with a psychiatric interview and safety checks to confirm they are eligible and to review the risks and procedures. Eligible participants will then have a baseline visit that includes a blood draw, vital signs, urine drug and pregnancy tests when needed, and a 7 Tesla MRI/MRS scan focused on brain chemistry and structure. After the baseline visit, participants will take NR capsules by mouth at home, 1500 milligrams in the morning and 1500 milligrams in the early afternoon each day, for about 2 weeks, for a total daily dose of 3000 milligrams. They will be asked to avoid alcohol and other drugs during the study and to complete a short food diary near the end of the dosing period so that researchers can track diet. On the last day of taking NR, participants will return for repeat MRI/MRS scans, blood tests, and vital signs so that researchers can compare brain and blood measures before and after NR treatment. Researchers will compare each participant's brain NAD+ to NADH ratio and other bioenergetic markers before and after NR to see if NR changes these measures in a consistent way. If NR raises brain NAD+ and improves measures of energy metabolism in healthy adults, this may provide important background information for future studies that test whether NR can help people with psychiatric or neurological disorders linked to mitochondrial dysfunction and oxidative stress. There is no expected direct health benefit for participants, but their involvement may help improve understanding of how NR affects human brain metabolism.