Beta-Carotene
Beta-Carotene is a tier 2 form of Vitamin A, used in 4,052 on-market products .
4,052
on-market products
tier 2
quality tier
n/a
elemental fraction
Why this tier: Requires enzymatic intestinal conversion to retinol, with conversion efficiency that varies between individuals; the current NIH ODS ratios are 12:1 for dietary beta-carotene and 2:1 for supplemental beta-carotene. High-dose supplemental beta-carotene (20-30mg/day) also increased lung cancer risk specifically in smokers (and asbestos-exposed workers) in two large RCTs -- a safety note, not a blanket warning against beta-carotene generally.
Source: NIH ODS Vitamin A fact sheet; ATBC 1994 PMID 8127329, CARET/Omenn 1996 PMID 8602180