title: Recommended dietary intakes (RDI) of vitamin A in humans.
abstract: Mean and median dietary intakes of vitamin A in the US are approximately 1000 and 624 retinol equivalents, respectively. In this paper a satisfactory vitamin A status is defined as a total-body pool that provides adequate vitamin A to meet all known physiological needs and a reserve for 4 mo on low intakes or during stress. Mean dietary intakes required to maintain an adequate body pool (ie, 20 micrograms vitamin A/g liver [0.07 mumol/g]) in reference 76-kg men and 62-kg women are 506 and 413 micrograms retinol, respectively. Recommended dietary intakes (RDI) for nearly all reference men and women are 700 micrograms and 600 micrograms, respectively. Vitamin A needs in infants, children, the elderly, and pregnant and lactating women are quantified. The toxicity of vitamin A in early pregnancy, for which a safe intake level is not known, is stressed. On many grounds these suggested lower RDI values are preferable to the 1980 RDA values.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002338:Carotenoids / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004032:Diet; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007774:Lactation; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000517:prevention & control; D009751:Nutritional Requirements; D009752:Nutritional Status; D011247:Pregnancy; D014801:Vitamin A / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism
chemical_list: D014801:Vitamin A; D002338:Carotenoids