The extent of a focal tendon abnormality was intrasubstance in none (0%) of 16 patients with full-thickness tears, one (20%) of five patients with bursal surface partial-thickness tears, two (20%) of 10 patients with articular surface partial-thickness tears, and two (15%) of 13 patients with tendons without tear.
1 Adequate Intake (AI), where no RDA has been established, but the amount established is somewhat less firmly believed to be adequate for everyone in the demographic group.  Tolerable upper intake levels (UL), to caution against excessive intake of nutrients (like vitamin A) that can be harmful in large amounts.
Here are the RDA levels of B1 according to the U.S. National Library of Medicine: 1  Males who are 14 and older should consume 1.2 milligrams per day (mg/day). 2  Females who are 14 to 18 years old should consume 1.0 mg/day.