Effects of Taking Prenatal Vitamin-mineral Supplements During Lactation on Iron Status and Markers of Oxidation

Most breastfeeding women are told by their health care provider to continue taking prenatal vitamins after they give birth. A woman's requirement for iron while breastfeeding is low, yet prenatal vitamins contain a large amount of iron. The purpose of this study is to see if breastfeeding women are getting too much iron when taking prenatal vitamins.

Study Overview

• Status: Completed
• Conditions: Iron Overload; Oxidative Stress; Iron-deficiency Anemia
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: Iron

Detailed Description

Even though iron requirements are much lower for lactating women than for pregnant or non-pregnant, non-lactating women, and iron stores during lactation are often high due to release of iron from the additional maternal erythrocytes produced during pregnancy, iron supplements are often taken by lactating women in the U.S. Many studies have shown that higher iron status is associated with higher risk of certain chronic diseases (e.g. cancer and cardiovascular diseases). The overall goal of this proposed study is to understand the potential for oxidative stress due to iron supplementation, and possible mechanisms for these effects, and to identify safe and efficacious ways to ensure adequate iron status during lactation. The specific aims are:

1. To compare markers of lipid oxidation (urinary isoprostane) and DNA damage (urinary 8-OHdG (urinary 8-hydroxy-2'-deoxyguanosine)) among 3 treatment groups: (iron given between meals (27 mg daily, in a multivitamin-mineral supplement), iron given with meals (27 mg daily, in a multivitamin-mineral supplement) and multivitamin-mineral supplement with no iron, given between meals) at the beginning and end of 3 months of treatment in 114 lactating women.
2. To compare hemoglobin and iron status (ferritin, transferrin saturation, and hepcidin) before and after treatment among the three treatment groups described above.

• Study Type: Interventional
• Enrollment (Actual): 114
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Sacramento, California, United States, 95817
      • UC Davis Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Women less than 4 weeks postpartum
• 18 years of age or older
• Took prenatal vitamins for at least 3 months during pregnancy
• Successfully initiated breastfeeding

Exclusion Criteria:

• Anemic (Hgb < 110 g/L)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Iron with meals; Prenatal vitamin without iron plus capsule containing 27 mg of iron taken with meals	Dietary supplement: Iron; Iron as iron sulfate
Experimental: Iron between meals; Prenatal vitamin without iron plus capsule containing 27 mg of iron taken between meals	Dietary supplement: Iron; Iron as iron sulfate
Placebo Comparator: Placebo; Prenatal vitamin without iron plus capsule containing calcium carbonate (placebo) taken between meals	Dietary supplement: Placebo; Placebo capsule

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxidative stress	Isoprostane and 8-OHdG	3 month
Iron status	Ferritin, transferrin saturation, hepcidin	3 month

Collaborators and Investigators

• Sponsor: University of California, Davis
• Investigators: Principal Investigator: Kathryn G Dewey, PhD, Professor

Study record dates

Study Major Dates

• Study Start: October 1, 2008
• Primary Completion (Actual): April 1, 2010
• Study Completion (Actual): April 1, 2010

Study Registration Dates

• First Submitted: January 8, 2010
• First Submitted That Met QC Criteria: January 11, 2010
• First Posted (Estimate): January 12, 2010

Study Record Updates

• Last Update Posted (Actual): May 30, 2017
• Last Update Submitted That Met QC Criteria: May 25, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Keywords: Oxidative stress; Iron; Lactation; Breastfeeding; Iron status and oxidative stress during lactation
• Additional Relevant MeSH Terms: Metabolic Diseases; Hematologic Diseases; Anemia, Hypochromic; Anemia; Iron Metabolism Disorders; Anemia, Iron-Deficiency; Iron Overload; Physiological Effects of Drugs; Trace Elements; Micronutrients; Iron
• Other Study ID Numbers: 200816261