Carotene-rich plant foods ingested with minimal dietary fat enhance the total-body vitamin A pool size in Filipino schoolchildren as assessed by stable-isotope-dilution methodology

Am J Clin Nutr. 2007 Apr;85(4):1041-9. doi: 10.1093/ajcn/85.4.1041.


Background: Strategies for improving the vitamin A status of vulnerable populations are needed.

Objective: We studied the influence of the amounts of dietary fat on the effectiveness of carotene-rich plant foods in improving vitamin A status.

Design: Schoolchildren aged 9-12 y were fed standardized meals 3 times/d, 5 d/wk, for 9 wk. The meals provided 4.2 mg provitamin A carotenoids/d (mainly beta-carotene) from yellow and green leafy vegetables [carrots, pechay (bok choy), squash, and kangkong (swamp cabbage)] and 7, 15, or 29 g fat/d (2.4, 5, or 10 g fat/meal) in groups A, B, and C (n = 39, 39, and 38, respectively). Other self-selected foods eaten were recorded daily. Before and after the intervention, total-body vitamin A pool sizes and liver vitamin A concentrations were measured with the deuterated-retinol-dilution method; serum retinol and carotenoid concentrations were measured by HPLC.

Results: Similar increases in mean serum beta-carotene (5-fold), alpha-carotene (19-fold), and beta-cryptoxanthin (2-fold) concentrations; total-body vitamin A pool size (2-fold); and liver vitamin A (2-fold) concentrations were observed after 9 wk in the 3 study groups; mean serum retinol concentrations did not change significantly. The total daily beta-carotene intake from study meals plus self-selected foods was similar between the 3 groups and was 14 times the usual intake; total fat intake was 0.9, 1.4, or 2.0 times the usual intake in groups A, B, and C, respectively. The overall prevalence of low liver vitamin A (<0.07 mumol/g) decreased from 35% to 7%.

Conclusions: Carotene-rich yellow and green leafy vegetables, when ingested with minimal fat, enhance serum carotenoids and the total-body vitamin A pool size and can restore low liver vitamin A concentrations to normal concentrations.

Publication types

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

MeSH terms

  • Anthropometry
  • Antioxidants / metabolism
  • Antioxidants / pharmacokinetics*
  • Biological Availability
  • Carotenoids / blood
  • Carotenoids / pharmacokinetics*
  • Child
  • Chromatography, High Pressure Liquid / methods
  • Deuterium
  • Dietary Fats / administration & dosage
  • Dietary Fats / pharmacology*
  • Dose-Response Relationship, Drug
  • Female
  • Helminthiasis / blood
  • Helminthiasis / complications
  • Humans
  • Indicator Dilution Techniques
  • Isotope Labeling
  • Liver / chemistry
  • Liver / metabolism
  • Male
  • Nutritional Status
  • Nutritive Value
  • Philippines
  • Vegetables*
  • Vitamin A / blood
  • Vitamin A / metabolism*
  • Vitamin A Deficiency / diet therapy*
  • Vitamin A Deficiency / metabolism
  • Vitamin A Deficiency / prevention & control
  • beta Carotene / blood
  • beta Carotene / pharmacokinetics


  • Antioxidants
  • Dietary Fats
  • beta Carotene
  • Vitamin A
  • Carotenoids
  • Deuterium