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.
B2 is Riboflavin, one of the essential vitamins, and is needed for many vital cellular processes. Good sources of B2 are eggs, milk, cheese, leafy greens, liver, mature soybeans, yeast and almonds. The RDA is 1.3 mg/day and there is no established upper limit.