The Effect of Ovotransferrin and Lactoferrin on Iron Absorption From Ferrous Sulfate in Adult Women
Condition: Iron-deficiency
MeSH terms: Anemia, Iron-Deficiency; Iron Deficiencies
Study type: Interventional

Summary: 
      OTf is a monomeric glycoprotein of 686 amino acid residues and, as a member of the
      transferrin family, folds into two homologous globular lobes, each containing a single
      reversible Fe3 + binding site located within the interdomain cleft of each lobe. A comparison
      of apo (metal-free) and holostructures shows that iron binding or release in OTf occurs via a
      mechanism that involves opening or closing domains. human lactoferrin, transferrin, and OTf
      share the same reversible iron binding mechanism. Lactoferrin (Lf) is a 77 kDa glycosylated
      protein highly concentrated in human and bovine milk and can exist in an apo (metal free)
      state or can bind two ferric ions with very high affinity (k = 1022 M-1) forming holo-Lf . It
      has been recently reported that the addition of apo-Lf to a test meal containing FeSO4
      significantly increased (+56%) iron absorption in young infants [19]. Despite these positive
      results in infants, to our knowledge, the ability of Lf to improve iron absorption from FeSO4
      has not yet been assessed in adult women.

      OTf and Lf will be tested as iron absorption enhancers by comparing the fractional iron
      absorption with that of FeSO4, the most widely used iron supplement. This study will provide
      information on how to improve iron absorption.In a randomized single-blind crossover study,
      the iron bioavailability is determined by means of stable iron isotope technology via the
      incorporation of stable isotopes from intrinsically labeled compounds into the erythrocytes
      14 days after the study product.
    

Detailed description: 
      Iron deficiency remains a major public health problem in both developed and developing
      countries. At present, iron deficiency is mostly combated with iron supplements in the form
      of iron salts, especially iron sulfate. Iron salts are absorbed via the nonhemic iron route
      via the DMT-1 receptor, the rate of absorption being 20% of the total iron content. The
      dietary supplement industry tries to counteract this problem and to supply the required
      amount of iron by increasing the iron concentration in the dietary supplements in order to
      compensate for the low absorption rate. However, the high dosage of iron leads to side
      effects. It would be more effective to maximize iron absorption rather than a high dose of
      iron. Chicken protein ovotransferrin (OTf) is recognized as an iron-binding protein and a
      member of the transferrin family. OTf has amino acid sequences that are identical to chicken
      serum transferrin and shows approximately 50% homology with mammalian transferrin and
      lactoferrin. Despite its iron binding properties and safety for human consumption, no studies
      have evaluated OTf as an enhancer of iron absorption in humans.

      OTf is a monomeric glycoprotein of 686 amino acid residues and, as a member of the
      transferrin family, folds into two homologous globular lobes, each containing a single
      reversible Fe3 + binding site located within the interdomain cleft of each lobe. A comparison
      of apo (metal-free) and holostructures shows that iron binding or release in OTf occurs via a
      mechanism that involves opening or closing domains. human lactoferrin, transferrin, and OTf
      share the same reversible iron binding mechanism.

      Lactoferrin (Lf) is a 77 kDa glycosylated protein highly concentrated in human and bovine
      milk and can exist in an apo (metal free) state or can bind two ferric ions with very high
      affinity (k = 1022 M-1) forming holo-Lf . There are various studies that show the iron
      bioavailability of intrinsically labeled holo-Lf and apo- Lf and FeSO4. Lf appears to be a
      good source of bioavailable iron in both infants and in adults. Whether this is due to iron
      absorption through the Lf receptor and/or due to iron released from Lf joining the common
      non-heme iron pool and being subsequently absorbed, remains uncertain. The high affinity of
      OTf for iron (∼1030 M-1) at pH 7.5 implies that in presence of apo-OTf, iron will be
      sequestered. Lf also possesses the ability to bind iron (binding constants of ∼1022-1024 M-1)
      and retain it at lower pH. This difference in iron binding capacity, however, is not
      sufficient to establish conclusive statements regarding the activity of OTf in iron
      absorption.

      It has been recently reported that the addition of apo-Lf to a test meal containing FeSO4
      significantly increased (+56%) iron absorption in young infants. Despite these positive
      results in infants, to our knowledge, the ability of Lf to improve iron absorption from FeSO4
      has not yet been assessed in adult women. Furthermore, despite its iron-binding properties
      and safety for human consumption, to the best of our knowledge, no studies have assessed OTf
      as an enhancer of iron absorption in humans. Therefore the use of OTf and Lf as iron
      absorption enhancers by comparing fractional iron absorption with that of FeSO4, the most
      commonly used iron supplement is investigated. This study will provide information regarding
      iron absorption enhancement, as well the behavior of OTf and Lf in adult women.

      OTf and Lf will be tested as iron absorption enhancers by comparing the fractional iron
      absorption with that of FeSO4, the most widely used iron supplement. This study will provide
      information on how to improve iron absorption.In a randomized single-blind crossover study,
      the iron bioavailability is determined by means of stable iron isotope technology via the
      incorporation of stable isotopes from intrinsically labeled compounds into the erythrocytes
      14 days after the study product.

      Participants are given OTf, Lf and iron sulfate solutions. To quantify this, stable iron
      isotopes are used as marker substances. Stable isotopes exist in nature and in our body and
      there are no risks associated with their ingestion. No changes in the iron status of the
      subjects are expected during the study.35 women of childbearing age are being recruited for
      the study.
    

Intervention name(s): FeSO4 + OTf; FeSO4 + Lf; FeSO4
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): OTf (apo ovotransferrin) + FeSO4; Lf (lactoferrin) + FeSO4; Ferrous sulfate
Intervention MeSH terms: Fesoterodine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Treatment