BACKGROUND AND SIGNIFICANCE
Iron deficiency is a major cause of disease burden worldwide, affecting 1-2 billion
people globally. While often considered an issue in developing nations, low iron intake
is a growing problem in the US and other industrialized nations, particularly affecting
women of reproductive age. In the US, 20% of women aged 18-45 have insufficient iron
intake (below the EAR of 18 mg/day) and this number that has been growing over the last
decades. This is, in part, due to reduced concentrations in foods and lower intakes of
iron-containing foods. Moreover, iron-rich food sources also contain vitamin B12, which
is an important co-factor in iron metabolism.
There is, therefore, a strong need to develop strategies that can improve iron status in
women of reproductive age, given the generally low intakes of iron-containing sources in
this demographic. Besides increasing iron intake, a promising strategy to improve iron
status is to ingest compounds that can promote iron uptake. A particularly promising
compound to increase iron uptake is lactoferrin.
Lactoferrin (LF) is an iron-binding glycoprotein enriched in mammalian milk. LF binds
iron with exceptionally high affinity and is transferred via a variety of receptors into
and between cells, serum, bile, and cerebrospinal fluid. It also has important
immunological properties, particularly being anti-inflammatory and anti-viral.
LF supplementation has shown initial promise for enhancing iron status in women of
reproductive age. A previous study on female long-distance runners, a group at heightened
risk for iron-deficiency anemia, found that the combined supplementation of lactoferrin
and iron was able to maintain serum ferritin (an indicator of iron status) and red blood
cell counts, whereas supplementation with iron alone did not maintain serum ferritin
levels and red blood cell counts during the 8-week training period.
To ensure proper absorption, LF is best ingested in a dairy matrix. That is because of
the presence of an LF receptor in the human small intestine that can bind bovine LF,
likely preventing the use of iron by gut pathogens. This, in turn, results in enhanced
systemic availability of iron where it can exert beneficial tissue effects and contribute
to adequate iron status.
There is also evidence from in vitro work to suggest that lactoferrin can have
anti-inflammatory properties, which could further improve serum iron and hemoglobin
concentrations as inflammation negatively impacts iron metabolism. However, more clinical
nutrition work is certainly needed to study these potential beneficial effects of LF.
STUDY OBJECTIVES
To determine the effects of lactoferrin & iron supplementation in whey protein
matrix on markers of iron absorption (serum ferritin) compared to a lactoferrin,
iron, vitamin b12 and non-milk protein control (rice protein) and a lactoferrin,
iron, vitamin b12 control without protein (maltodextrin).
To determine the effects of lactoferrin & iron supplementation in whey protein
matrix on markers of iron metabolism (RBC, Hb, Hc) compared to a lactoferrin, iron,
vitamin b12 and non-milk protein control (rice protein) and a lactoferrin, iron,
vitamin b12 control without protein (maltodextrin).
To determine the effects of lactoferrin & iron supplementation in whey protein
matrix on plasma inflammatory markers (IL-6, TNF-α, and C-reactive protein) compared
to a lactoferrin, iron, vitamin b12 and non-milk protein control (rice protein) and
a lactoferrin, iron, vitamin b12 control without protein (maltodextrin).
DESIGN AND PROCEDURES
3.1 Study duration Participant involvement will be 17 weeks. Week one, participants will
go through the initial screening process. participants will consume two servings of
supplement per day for the remaining 16 weeks.
3.2 Participants We will recruit 90 physically active female participants between 18-30
yrs, who are physically active (>2 days/week) with a BMI ≥18 and ≤30 kg/m2.
3.3 Description of study visits
Pre-screening (week 1. 15 minutes): Interested participants will have access to the
informed consent via a link to recruitment materials. Participants that reach out via
email or phone will be provided with a REDCap survey link to the screening questions that
asks them further details about their health, diet, and sleep (see inclusion/exclusion
criteria). Only minimum personal health information will be collected to determine
eligibility. Responses will be reviewed by a study team member (all study team members
will have completed the necessary CITI training) and potentially eligible candidates will
be contacted to schedule a consent/screening visit. The pre-screen is to confirm that the
participant meets most of the criteria before the subject is scheduled for a consent
meeting. This will limit subject and research staff time burden. Information gathered
will not be attached to identifiers and will be deleted if they decide to not participate
or do not meet criteria. If participants screen as a "maybe", they will be contacted by
phone or email with follow up questions to determine eligibility. Participants who are
taking some medications that may interfere, but who are willing to stop cease usage will
require a doctor's release to stop taking prescription medications.
Consent (Week 1. Duration: 1 hour): This visit will take place at the Center for Human
Nutrition Studies or will happen virtually (via a tele-call platform such as Zoom). This
visit will include the following. Participants will review the consent document with a
member of the study team; once all questions have been satisfactorily answered,
participants will be asked to sign and date the consent form if participants wish to
participate in the study. Participants will be asked to sign the consent form
electronically through REDCap using a unique link that is provided to them.
When deemed eligible and contacted, participants can combine the consent visit with the
screening visit described below. If participants wish to do so, participants will be
asked to come to the Center for Human Nutrition Studies in the morning after an overnight
fast, requiring them not to eat or chew gum (nothing but water) 12 hours prior to their
arrival. This information will not apply if the investigators do a virtual consent visit
first. If participants agree to participate, they will come for the in-person screening
visit.
Initial Screening Visit (Week 1. Duration: 1 hour): Assuming participants pre-qualify for
the study, and are interested in participating, they will undergo an in-person screening
visit. This visit will take place at the Center for Human Nutrition Studies. This visit
will be performed in the morning, will last approximately 1 hour, and requires
participants not to eat anything or chew gum (nothing but water) for 12 hours prior to
their arrival time. This visit will include the following:
Body mass and height: The investigators will measure their height and body weight to
determine their body mass index.
Blood draw: Participants will have blood drawn from a forearm or hand vein for
routine lab analyses (basic metabolic panel and lipid panel), hemoglobinA1c and
serum ferritin. The amount drawn will be 15 mL (1 tablespoon) total. If they are of
childbearing potential, a pregnancy test will be performed as part of this screening
blood draw. It must be negative to participate in this study.
Questionnaires: If participants agree to participate, participants will be emailed a
link with questionnaires to fill out. These questionnaires will ask detailed
questions about their diet (7-day food log), potential GI responses such as
abdominal discomfort, diarrhea, constipation, gas and bloating using The
Gastrointestinal Symptom Rating Scale (GSRS), sleep such as duration and quality,
and physical activity patterns, which are part of the screening and/or study
process.
Blood pressure: A blood pressure measurement will be taken using an automated upper
arm blood pressure monitor. A total of three measurements will be taken.
Intervention Assignment and Intervention (Week 2 - 17. Duration: 10 min per week): If
participants meet the inclusion criteria, participants will be randomly assigned to one
of three groups for the duration of the study. The group assignment is random (like the
flip of a coin) and participants will not know which group participants are in.
Lactoferrin in whey group: If participants have been randomly assigned to the
lactoferrin in whey protein group, participants they will receive weekly allotments
of whey protein concentrate enriched with lactoferrin (a protein found in milk; 200
mg/serving), vitamin B12 (5.2µg/serving) and iron (6 mg/serving). This supplement
will come in a flavored powder packaged individually in sachets.
Lactoferrin alone group: If participants have been randomly assigned to the
lactoferrin alone group, they will receive weekly allotments of maltodextrin
enriched with B12 (5.2µg/serving), lactoferrin (200mg/serving) and iron (6
mg/serving). This supplement will come in the form of a flavored powder and each
serving will be packaged individually in sachets.
Rice protein group: If participants have been randomly assigned to the whey protein
group, they will receive weekly allotments of rice protein concentrate enriched with
B12 (5.2µg/serving) and iron (6 mg/serving). This supplement will come in the form
of a flavored powder and each serving will be packaged individually in sachets.
Supplementation schedule: Participants will be asked to take their assigned
supplement twice daily, once 30 min before their morning meal, and once between
lunch and dinner.
Weekly pickup: Participants will be asked to pick up the assigned protein
supplements at the Center for Human Nutrition Studies once weekly and return the
used sachets for record keeping at this visit. They will also be asked to complete
questionnaires once weekly regarding GI responses, sleep, and physical activity
patterns.
Tracking: Participants will be asked to mark the time and date that participants
take their assigned supplements in an online database called REDcap (described
below) so that the research team can determine compliance and provide reminders if
necessary.
Mid intervention check-in (Week 9. Duration: 1 hour):
• Questionnaires: 7-day food log The questionnaire will include a 7-day recall of food
consumed over the last week including what foods, how much and at about what time.
Final visit (Week 17. Duration: 1 hour): This visit will take place at the Center for
Human Nutrition Studies. This visit will be performed in the morning, will last
approximately 1 hour, and requires participants not to eat anything or chew gum (nothing
but water) for 12 hours prior to their arrival time. This visit will include the
following:
Body mass and height: The investigators will measure their height and body weight to
determine their body mass index.
Blood draw: Participants will have blood drawn from a forearm or hand vein for
routine lab analyses and iron status. The amount drawn will be 30 mL (2 tablespoon)
total.
Questionnaires: These questionnaires will ask detailed questions about their diet
(7-day food log), GI responses, sleep, and physical activity patterns.
Blood pressure: A blood pressure measurement will be taken using an automated upper
arm blood pressure monitor. A total of three measurements will be taken.