title: The contribution of plant foods to the vitamin A supply of lactating women in Vietnam: a randomized controlled trial.
abstract: BACKGROUND
  More information is needed on the efficacy of carotenoids from plant foods in improving vitamin A status.
  
  
  OBJECTIVE
  We aimed to quantify the efficacy of provitamin A-rich vegetables and fruit in improving vitamin A status.
  
  
  METHODS
  Breastfeeding women in 9 rural communes in Vietnam were randomly allocated to 1 of 4 groups: the vegetable group (n = 73), which ingested 5.6 mg beta-carotene/d from green leafy vegetables; the fruit group (n = 69), which ingested 4.8 mg beta-carotene/d from orange or yellow fruit; the retinol-rich group (n = 70), which ingested 610 microg retinol/d from animal foods and 0.6 mg beta-carotene/d; and the control group (n = 68), which ingested 0.4 mg beta-carotene/d. Meals of groups 1, 2, and 4 contained <30 microg retinol/d. Lunch and dinner were provided 6 d/wk for 10 wk.
  
  
  RESULTS
  Mean (95% CI) changes in serum retinol concentrations of the vegetable, fruit, retinol-rich, and control groups were 0.09 (0.03, 0.16), 0.13 (0.07, 0.19), 0.25 (0.17, 0.33), and 0.00 (-0.06, 0.06) micromol/L, respectively. Mean (95% CI) changes in breast-milk retinol concentrations were 0.15 (0.04, 0.27), 0.15 (0.02, 0.28), 0.48 (0.32, 0.64), and -0.06 (-0.21, 0.09) micromol/L, respectively. According to these findings, the equivalent of 1 microg retinol would be 12 microg beta-carotene (95% CI: 8, 22 microg) for fruit and 28 microg beta-carotene (17, 84 microg) for green leafy vegetables. Thus, apparent mean vitamin A activity of carotenoids in fruit and in leafy vegetables was 50% (95% CI: 27%, 75%) and 21% (7%, 35%), respectively, of that assumed.
  
  
  CONCLUSIONS
  The bioavailability of carotenoids from vegetables and fruit is less than previously assumed.
authors.affiliation: National Institute of Nutrition, Hanoi, Vietnam.
authors.forename: Nguyen Cong
authors.initials: NC
authors.lastname: Khan
authors.forename: Clive E
authors.initials: CE
authors.lastname: West
authors.forename: Saskia
authors.initials: S
authors.lastname: de Pee
authors.forename: Diane
authors.initials: D
authors.lastname: Bosch
authors.forename: Ha Do
authors.initials: HD
authors.lastname: Phuong
authors.forename: Paul Jm
authors.initials: PJ
authors.lastname: Hulshof
authors.forename: Ha Huy
authors.initials: HH
authors.lastname: Khoi
authors.forename: Hans
authors.initials: H
authors.lastname: Verhoef
authors.forename: Joseph Gaj
authors.initials: JG
authors.lastname: Hautvast
mesh_terms: D000328:Adult; D001682:Biological Availability; D002338:Carotenoids / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007223:Infant; D007408:Intestinal Absorption; D007774:Lactation / Q000378:metabolism*; D008895:Milk, Human / Q000737:chemistry* / Q000187:drug effects; D009751:Nutritional Requirements; D009752:Nutritional Status; D012424:Rural Population; D014675:Vegetables / Q000737:chemistry; D014744:Vietnam; D014801:Vitamin A / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D014815:Vitamins / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D014815:Vitamins; D014801:Vitamin A; D002338:Carotenoids