Effect of Vitamin C on Iron Absorption
Condition: Iron Deficiency
MeSH terms: Iron Deficiencies
Study type: Interventional

Summary: 
      Iron deficiency is a common health problem worldwide. Ferrous fumarate (a form of iron) is
      often added to foods in an effort to prevent iron deficiency. Vitamin C can improve the
      amount of iron that the body absorbs, therefore it is often added to foods too. However, we
      don't know if vitamin C really increases the absorption of iron from ferrous fumarate.

      This study will measure the iron absorption in children from a meal containing some ferrous
      fumarate with and without vitamin C. The study will include 4 visits to the Children's
      Nutrition Research Center in Houston, TX.
    

Detailed description: 
      This study involves four outpatient visits. Two test meals will be given (during visits 2 and
      3) and two blood draws will be done (visits 3 and 4). A 2-3 hour fast prior to the visit is
      required. Therefore, subjects may come in first thing in the morning (for breakfast meal), at
      lunch, or in the afternoon (snack). Subjects may be scheduled to come in during the week or
      on weekends; however, each individual subject will need to return at the same time of day for
      each subsequent visit. Visit procedures are described below.

      Visit 1: Subjects will be admitted to the GCRC as an outpatient after a 2-3h fast and given a
      reference dose of 1mg iron-58 sulfate as an aqueous solution with 50mg ascorbic acid. They
      will be observed for 2h after this dose and water will be freely available. No food will be
      allowed. After 2h subjects will be discharged home and food allowed.

      Visit 2: One to 10 days later subjects will be again admitted as an outpatient after a 2-3h
      fast. They will consume a meal of a bread muffin labelled with 4mg of iron-57 as ferrous
      fumarate, and a glass of apple juice containing 0 or 25mg ascorbic acid. The order of
      ascorbic acid supplementation or non-supplementation will be decided by random. No food will
      be allowed after the meal. After 2h subjects will be discharged home and food allowed.

      Visit 3: Two weeks (+/- 3 days) later they will be readmitted after a 2-3h fast and the
      second visit repeated. During this admission the apple juice will contain either 0 or 25mg
      ascorbic acid, the opposite of what was given to the subject in visit 2. Immediately prior to
      administration of the second test meal, 10mL blood will be drawn for measurement of iron
      nutritional parameters (e.g. CBC, serum ferritin) and iron isotope ratio measurement.
      Incorporation of iron-57 will be used to calculate iron absorption from the test meal given
      during visit 2, and incorporation of iron-58 used to measure absorption from the reference
      dose (a measure of iron status). No food will be allowed after the meal and blood draw. After
      2h subjects will be discharged home and food allowed.

      Visit 4: Two weeks (+/- 3 days) later subjects will be admitted for a 10mL blood draw as
      described above. Incorporation of iron-57 will reflect the absorption of ferrous fumarate
      from the test meal given during visit 3.
    

Intervention name(s): Vitamin C
Intervention type(s): Dietary Supplement
Intervention description(s): Visit 1: Subjects will receive 1mg iron-58 sulfate as an aqueous solution with 50mg ascorbic acid.
Visit 2: Subjects will consume a meal of a bread muffin labelled with 4mg of iron-57 as ferrous fumarate, and a glass of apple juice containing 0 or 25mg ascorbic acid.
Visit 3: During this admission the apple juice will contain either 0 or 25mg ascorbic acid, the opposite of what was given to the subject in visit 2.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Basic Science
Keywords: Iron; Absorption; Ascorbic Acid; Ferrous Fumarate