Bioavailability of iron from spinach using an in vitro/human Caco-2 cell bioassay model

Habitation (Elmsford). 2004;10(1):7-14. doi: 10.3727/154296604774808900.


Spinach (Spinacia oleracea) cv Whitney was tested for iron bioavailabilty using an in vitro human intestinal cell culture ferritin bioassay technique previously developed. Spinach was cultured in a growth chamber for 33 days, harvested, and freeze-dried. Total iron in the samples was an average of 71 micrograms/g dry weight. Spinach was digested in vitro (pepsin and 0.1 M HCl followed by pancreatin and 0.1 M NaHCO3) with and without the addition of supplemental ascorbic acid. Caco-2 cell cultures were used to determine iron bioavailability from the spinach mixtures. Production of the iron-binding protein ferritin in the Caco-2 cells showed the supplemental ascorbic acid doubled bioavailability of iron from spinach. The data show fresh spinach is a poor source of iron, and emphasize the importance of evaluation of whole meals rather than single food items. The data support the usefulness of the in vitro/Caco-2 cell ferritin bioassay model for prescreening of space flight diets for bioavailable iron.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ascorbic Acid / administration & dosage
  • Ascorbic Acid / physiology*
  • Biological Availability
  • Caco-2 Cells
  • Dose-Response Relationship, Drug
  • Ferritins / biosynthesis*
  • Humans
  • Iron, Dietary / pharmacokinetics*
  • Models, Biological
  • Nutritive Value
  • Plant Proteins / analysis
  • Predictive Value of Tests
  • Space Flight
  • Spinacia oleracea / chemistry*
  • Spinacia oleracea / growth & development


  • Iron, Dietary
  • Plant Proteins
  • Ferritins
  • Ascorbic Acid