Clinical trial NCT00453648: Impact of Consumption of Orange-fleshed Sweet Potatoes on the Vitamin A Status of Bangladeshi Women of Reproductive Age
Official title: Efficacy of Daily Consumption of Sweet Potatoes for Increasing Total Body Vitamin A Pool Size, and the Effect of Consumption of Sweet Potatoes on Iron and Zinc Absorption in Bangladeshi Women of Reproductive Age
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Vitamin A Deficiency
Keywords: stable isotopes
vitamin A
beta-carotene
orange-fleshed sweet potatoes
iron
zinc
absorption
bioavailability
vitamin A equivalency
Bangladesh
women
Lead sponsor: University of California, Davis
Sponsor class: OTHER
Collaborators: name: International Centre for Diarrhoeal Disease Research, Bangladesh
First posted: 2007-03-29
Enrollment: 130
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The primary purpose of this study is to determine whether daily consumption of orange-fleshed sweet potatoes increases the vitamin A status of Bangladeshi women of reproductive age. Secondary purposes of the study are to determine whether consumption of orange-fleshed sweet potatoes has an effect on the intestinal absorption of dietary iron or dietary zinc in Bangladeshi women of reproductive age.

Detailed description: Biofortification of plant source foods is a promising strategy for increasing dietary vitamin A intake and vitamin A status in populations at risk of deficiency. The primary purposes of this study are:

1. to assess the efficacy of daily consumption of boiled or fried orange-fleshed sweet potatoes (OFSP) for increasing the vitamin A status of non-pregnant, non-lactating Bangladeshi women, and
2. to estimate the relative vitamin A equivalency of beta-carotene from the two different preparations of OFSP (boiled or fried).

Secondary purposes are to assess the effect of daily consumption of OFSP on intestinal absorption of iron and zinc. Specifically, 120 non-pregnant, non-lactating women at risk of vitamin A deficiency will be randomly assigned to one of the following 4 treatment groups to receive, 600 micrograms RAE/d, 6 d/wk, for 60 days as either:

1. boiled OFSP
2. fried OFSP
3. retinyl palmitate, or 0 micrograms RAE/d as white-fleshed sweet potato (WFSP)

The paired stable isotope dilution technique will be used to estimate total body vitamin A pool size before and after 60-days of supplementation. The efficacy of consumption of OFSP will be assessed by comparing the mean change in vitamin A pool size in the OFSP groups to the mean change in vitamin A pool size in the negative control group (WFSP group). Relative vitamin A equivalency factors will be estimated by comparing the mean change in vitamin A pool size in the OFSP groups with the mean change in vitamin A pool size in the retinyl palmitate group. Intestinal iron absorption and iron status will be assessed before and after the 60-day supplementation period in a subset of women (n=50); and intestinal zinc absorption and zinc status will be assessed after the 60-day supplementation period (n=50). Intestinal absorption of iron and zinc will be compared by treatment group to determine whether consumption of OFSP has any effect on iron or zinc absorption in these women.

Eligibility criteria: Inclusion Criteria:

* Serum retinol concentration \< 1.12 umol/L
* Serum C-reactive protein concentration \< 10 mg/L

Exclusion Criteria:

* Pregnant
* Lactating
* Diarrhea within past week
* Severe anemia (\< 9g Hb/dL)
* Symptoms of nightblindness
* Clinical symptoms of xerophthalmia
* Chronic disease

Primary outcomes:
measure: Total body vitamin A pool size
timeFrame: 3 years
Secondary outcomes:
measure: Iron absorption
timeFrame: 3 years
Other outcomes:
Locations:
Study officials:
affiliation: University of California, Davis
name: Marjorie J Haskell, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of California, Davis
name: Kenneth H Brown, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh
name: Kazi Jamil, MBBS, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Jamil KM, Brown KH, Jamil M, Peerson JM, Keenan AH, Newman JW, Haskell MJ. Daily consumption of orange-fleshed sweet potato for 60 days increased plasma beta-carotene concentration but did not increase total body vitamin A pool size in Bangladeshi women. J Nutr. 2012 Oct;142(10):1896-902. doi: 10.3945/jn.112.164830. Epub 2012 Aug 29.