A deficiency of riboflavin can be primary - poor vitamin sources in one's daily diet - or secondary, which may be a result of conditions that affect absorption in the intestine, the body not being able to use the vitamin, or an increase in the excretion of the vitamin from the body.
Substantial evidence means more than a mere scintilla. It means such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.. Richardson v. Perales, 402 U.S. 389, 401 (1971).
Primary Evidence. An authentic document or item that is offered as proof in a lawsuit, as contrasted with a copy of, or substitute for, the original. Primary evidence, more commonly known as best evidence, is the best available substantiation of the existence of an object because it is the actual item. It differs from secondary evidence, which is a copy of, or substitute for, the original.