Table 1: Inclusion and exclusion criteria.

Inclusion criteria
1. Age > 50–90 years
2. Screening cognitive function by the Thai Mental State Examination (TMSE) between 10 and 23 and/or MoCA between 7 and 20
3. Diagnosing mild to moderate dementia by following the Diagnosis and Statistical Manual of Mental Disorder, Fourth Edition (DSM-IV)
4. Can recognize and communicate
5. Do not have severe complications that influence patient cooperation with this study
6. Willing to participate in this study and conducts oneself follow by suggestion duration in this study
7. Volunteer or proxy is able to provide the consent

Exclusion criteria
1. Serum creatinine higher than 2 mg/dL
2. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, or alkaline phosphatase higher than 2.5 times of the upper normal range
3. Vitamin B12 deficiency
4. Hypothyroidism
5. Syphilis
6. Bleeding disorder or taking warfarin
7. Major depressive disorder
8. History of medicinal and herbal hypersensitivities
9. Having severe illness history
10. Intake of other supplements