Estimation of Vitamin A Stores in Children and Women in Guatemala and Relation With Potential Toxicity Markers
Condition: Vitamin A Status
Study type: Observational

Summary: 
      The goal of this study is to assess whether 3-5 years-old children who have Vitamin A intakes
      above the tolerable upper intake level (UL=900 ug per day) have higher total body Vitamin A
      stores and biomarkers of excessive vitamin A status, compared to children with Normal Vitamin
      A intakes (250-600 ug per day).
    

Detailed description: 
      The goal of this study is to assess whether VA intakes above the tolerable upper intake level
      (UL) and exposure to multiple programs are associated with are associated with 1) exposure to
      multiple VA intervention programs, and 2) elevated liver vitamin A concentration and
      biomarkers of excess vitamin A. Guatemala was selected as a study site because the country
      has a long standing national fortification program for vitamin A in sugar (law since 1975,
      re-launched and maintained since the 90´s). Typically, fortified sugar is used in more than
      90% of households at average concentrations of 9 to 10 µg/g of sugar. VA fortified foods, in
      the form of fortified sugar, foods prepared with fortified sugar and other fortified foods,
      reach children from 2 years old to adulthood. On the other hand, high dose VA supplements,
      provided by local health services, only reached 10.5% of children ages 6-59 month in 2013.
      Children ages 2-3 and 4-5 years old with VA intakes above and below the UL will be recruited
      together with their mothers to assess the cumulative effect of fortification on young
      children and their mothers. Data from Program of Food and Nutrition Security (PROSAN), of the
      Ministry of Health, Guatemala in 2013, shows that coverage in the 30 Health Areas of the
      country is 17.9%, the lowest is 4.4% (San Marcos) and the largest 33% (Petén). Four of the 30
      Region Areas correspond to the Department of Guatemala, in which urban and peri-urban areas
      of Guatemala City are included. In Central and North-West Guatemala Areas, coverage is 23 and
      22% respectively, both above national average coverage and within the 10 out of 30 top
      coverages. According to PROSAN data for Micronutrient Powders in 2013, all four regions
      North-East, North-West, South, and Central Guatemala areas are also around or above the
      national coverage (14%) with 21.8, 11.2, 17.3 and 13.8% coverage. Another advantage of
      remaining in the 4 areas of Health around Guatemala city is that the four combined amount for
      300,000 children of 0-59 month-old, that is more than 15% of the national children population
      reported. Even if coverages are low, population density will easier children recruitment.
    

Intervention name(s): High Vitamin A intake; Normal Vitamin A intake
Intervention type(s): Other; Other
Intervention description(s): Total Vitamin A stores will be assessed by isotopic measurement, 13C-Retinol will be given to the subject and blood wil be drawn on Day 4 to assess the isotopic dilution in the plasma. Other biochemical indicators will be assessed too, along with Dietary assessment (Food Frequency, 24 hours recalls).; Total Vitamin A stores will be assessed by isotopic measurement, 13C-Retinol will be given to the subject and blood wil be drawn on Day 4 to assess the isotopic dilution in the plasma. Other biochemical indicators will be assessed too, along with Dietary assessment (Food Frequency, 24 hours recalls).
Intervention MeSH terms: Vitamins; Vitamin A; Retinol palmitate
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Children and Women from Guatemala peri-urban areas or areas where High Vitamin A foods
        intake is reported. Convenience sampling according to the availability (time to participate
        in the study) of the participant, and acceptance of Blood sampling and Dietary assessments
      
Biospecimen description: 
      Venous blood will be drawn on Day 4 post C-13 Vitamin A administration (women and children)
      and one variable day (children only) to obtain plasma, serum, and buffy coat (Day 4), or only
      plasma on variable day post Vitamin A dose for children.
    
Keywords: Vitamin A; Isotopic dilution; dietary assessment