The recommended daily dosage of vitamin B1 for adults is 1.1 mg for women and 1.2 mg for men. Pregnant women and those who are breastfeeding may require higher amounts.

Vitamin B1 Dosage for Adults. If your blood tests don’t show vitamin B1 deficiency and you don’t take any supplements, you are getting enough of the vitamin through your daily diet.

Read on to learn more about vitamin B1, ... Dosage and how to take supplements. The recommended daily allowance of thiamine is 1.2 mg for males and 1.1 mg for females over the age of 18 years.

Find out how to take Thiamine (Vitamin B1)(drug) and its dose. ... Adult: PO – The recommended dose is 10-25 mg/day in single or divided doses. IM/IV- The recommended dose range is 20-100mg/day.