Retinol Equivalent

**Semantic type:** Quantitative Concept

**Definition:** An arbitrary unit for measurement of a vitamin A activity of provitamin A carotenoids (such as carotenes, xanthophylls, and compounds that arise from rearrangement of carotene I skeleton) in a mixed diet introduced by FAO/WHO Expert Group in 1967. The concept of the retinol equivalent (RE) is established on the following relationships among food sources of the vitamin A: one microgram of all-trans retinol is equal to one RE, one microgram of beta-carotene is equal to 0.167 RE, and one microgram of other pro-vitamin A carotenoids is equal to 0.084 RE.

**Synonyms:** - RAE - RE - Retinol Activity Equivalent - Retinol Equivalents - {RE} - {RE}