The Effect of SLC19A3 Inhibition on the Pharmacokinetics of Thiamine

Inclusion Criteria: 1. Male or female between the ages of 18-65 years old. 2. Eats a wide variety of food and willing to consume study diet (i.e. not on a specific diet such as Atkins, Fodmap, etc.). 3. Written informed consent obtained from the subject and ability for subject to comply with the requirements of the study. Exclusion Criteria: 1. Subjects who are pregnant, breastfeeding, or unwilling to practice birth control during participation in the study. 2. Self-reported severe food allergies or diet restrictions (vegans, vegetarians, Atkins, Fodmap, etc.) that would prevent consumption of study diets. 3. Subjects with extreme obesity (BMI \> 35). 4. Subjects who are smokers or have smoked in the past year and/or have smoked or ingested THC/marijuana in the past week, or who are unwilling to comply with a 1-week washout. 5. Subjects with any disease affecting or impairing the function of the liver, kidney or heart. 6. Subjects with moderate to severe hypertension. 7. Subjects with diabetes mellitus, hyperthyroidism, hypothyroidism, cardiovascular disease, glaucoma. 8. Subjects with gastrointestinal disease, gastrointestinal disorder, or gastrointestinal surgery. 9. Subjects with known infection with HIV, Hepatitis B (HBsAg) or Hepatitis C (no laboratory diagnostics concerning these diseases will be performed within the present study. Volunteers who are cured of past HepC infection are eligible to participate with doctor's approval letter). 10. Alcohol use on average \> 2 servings/day or \> 14 servings/wk (Serving size: 12oz beer/4oz wine/2oz hard liquor) or self-reported binge drinking. 11. Subjects that are on vitamin B supplements or multi-vitamins or who have taken vitamin B supplements or multi-vitamins in the past 30 days, or are not willing to comply with a 30-day washout of vitamin B supplements. 12. Subjects with possible folate deficiency. 13. Subjects taking any other clinically significant drugs as judged by the investigator. 14. Subjects with a condition, disease, or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data. 15. Female subjects undergoing treatment for infertility or hormone replacement therapy (Volunteers using hormonal birth control will not be excluded). 16. Subjects who have taken antimalarials in the past 60 days. 17. Participating in another research study while participating in this research study. 18. Non-English speaking 19. Subjects with abnormal laboratory results at screening as judged by the investigator or study physician.