Beta-Carotene
Beta-Carotene is a tier 2 form of Vitamin A, used in 3,503 on-market products .
3,503
on-market products
tier 2
quality tier
n/a
elemental fraction
Why this tier: Requires enzymatic intestinal conversion to retinol with substantial inter-individual variability (~65% CV in isotope-dilution studies); the 2001 IOM reassessment halved the assumed dietary conversion efficiency. High-dose supplemental beta-carotene (20-30mg/day) also increased lung cancer risk specifically in smokers in two large RCTs -- a safety note, not a blanket warning against beta-carotene generally.
Source: IOM 2001 DRI report (vitamin A chapter); ATBC 1994 PMID 8127329, CARET/Omenn 1996 PMID 8602180