During each Step, Basis (5 patients) or placebo (1 patient) will be given twice a day for 2 days. Patients will have frequent blood sampling performed for a 24 hour period following dosing on Day 1 and then at 48 hr. The measurements in blood will include NR/pterostilbene blood concentrations and NAD+ and NAAD (nicotinic acid adenine dinucleotide) concentrations in WBCs.