Impact of Consumption of Orange-Fleshed Sweet Potatoes on the Vitamin A Status of Bangladeshi Women of Reproductive Age

Condition(s) targeted: Vitamin A Deficiency

Intervention: Consumption of orange-fleshed sweet potatoes (Behavioral)

Phase: N/A

Status: Recruiting

Sponsored by: University of California, Davis

Official(s) and/or principal investigator(s):
Marjorie J Haskell, PhD, Principal Investigator, Affiliation: University of California, Davis
Kenneth H Brown, MD, Principal Investigator, Affiliation: University of California, Davis
Kazi Jamil, MBBS, PhD, Principal Investigator, Affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh

Overall contact:
Kazi Jamil, MBBS, PhD, Email: jamil@icddrb.org

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.

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 design: Treatment, Randomized, Double-Blind, Placebo Control, Parallel Assignment, Efficacy Study

Primary outcome:

Total body vitamin A pool size

Plasma retinol concentration

Plasma carotenoid concentrations

Secondary outcome:

Iron absorption

Serum ferritin

Hemoglobin concentration

Zinc absorption

Serum zinc concentration

Serum transferrin receptors

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.

Minimum age: 18 Years. Maximum age: 45 Years. Gender(s): Female.

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

Kazi Jamil, MBBS, PhD, Email: jamil@icddrb.org

International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh; Recruiting
Kazi Jamil, MBBS, PhD, Principal Investigator

Starting date: March 2006
Ending date: March 2008
Last updated: March 28, 2007