Vitamin A potency of carrot and spinach carotenes in human metabolic studies

Int J Vitam Nutr Res. 1990;60(3):229-35.


Changes in plasma retinol and carotenoids was measured in 17 young males after daily ingestion of grated carrots, carrot juice or spinach leaves for 2 weeks. Regression equations showed that the supply of 3350 and 4750 micrograms carotenes from 78 ml carrot juice (prepared from 185 g carrots) or 91 g grated carrots, respectively were adequate in maintaining plasma retinol at a constant level in subjects with initial plasma retinol of 1.2 mumol/l. Under similar experimental conditions, 280 g boiled spinach leaves providing 12,700 micrograms carotenes were required to maintain plasma retinol at a constant level. Apparent carotene digestibilities of 47 and 81% were obtained with carrot and spinach, respectively.

MeSH terms

  • Adolescent
  • Carotenoids / blood*
  • Child
  • Diet, Reducing
  • Eating
  • Humans
  • Male
  • Nutritive Value
  • Vegetables*
  • Vitamin A / blood*


  • Vitamin A
  • Carotenoids