Condition category
Nutritional, Metabolic, Endocrine
Date applied
03/06/2011
Date assigned
13/07/2011
Last edited
03/12/2013
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Lay summary under review 3

Trial website

Contact information

Type

Scientific

Primary contact

Prof Fernando Pizarro

ORCID ID

Contact details

Institute of Nutrition and Food Technology (INTA)
University of Chile
El Líbano 5540
Macul
Santiago
7830489
Chile
fpizarro@inta.uchile.cl

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

A randomized controlled trial investigating the effect of calcium supplementation on iron bioavailability in women aged 35 to 45 years old in Santiago, Chile

Acronym

Study hypothesis

1. Heme iron bioavailability decreases after 43 days of calcium supplementation
2. Non-heme iron bioavailability decreases after 43 days of calcium supplementation

Each participant was informed about the benefits, risks and reliability of the study through an informed consent. Participation was voluntary, remuneration was provided, and all subjects were free to withdraw at any stage of the study. Proceedings were done after reading and signed the written informed consent.

Ethics approval

Ethics Committee at the Institute of Nutrition and Food Technology (INTA), University of Chile approved on 18th June 2008, Ref: 13/2008, which was conducted in accordance with the Helsinki Declaration and the Nuremberg Code.

Radioisotopes doses were approved by the Chilean Commission of Nuclear Energy.

Study design

Randomized controlled double blind clinical trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Prevention

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

Iron bioavailability, iron-calcium interaction

Intervention

1. The target sample will consist of pre-menopausal women aged 35 to 45 years old, from the South East Area of Santiago Metropolitan Area, Chile
2. It will compare a group of 14 subjects supplemented with 600 mg of carbonate calcium with a control group (n = 14) receiving placebo
3. Follow up had a duration of 43 days
4. It was established that assessment of iron bioavailability and tracers of iron absorption that will be used are 55Fe and 59Fe radioisotopes
5. Iron absorption will be determined by Eakins and Brown double radioisotope technique
6. Additionally iron status, anthropometry and dietary micronutrient intake will be measured
7. Sample size calculation was 9 childbearing age women per group based on a difference of iron absorption of 5% between intervention and control group, with a statistical significance of 95% and a power of 80%
8. Considering a possible loss of the number of subjects it was decided recruiting 14 women per group, which correspond to a total of 28.
9. Participants will be randomly assigned to both groups
10. The intervention will last 58 days:
Day 1: Blood sample of 10ml to measure iron status. Heme iron intake labeled with 111 kBq of 55Fe, intake recorded and anthropometry
Day 2: Non heme iron intake labeled with 37 kBq 59Fe
Day 14: Blood sample of 20 ml to measure circulating radioactivity (cpm/ml)
Day 15: Beginning of supervised supplementation of carbonate calcium or placebo
Day 45: Intake of heme iron labeled with 111 kBq of 55Fe
Day 46: Intake of non heme iron intake labeled with 37 kBq of 59Fe
Day 57: Ending period of supervised supplementation of carbonate calcium or placebo
Day 58: Blood sample of 30 ml to measure circulating radioactivity (cpm/ml) and iron status
11. Bioavailabilty: For the administration of non heme radioisotope 50ml of an aqueous solution containing 3mg of iron as ferrous sulfate labeled with 37 kBq of 59FeCl3 will be used
12. For the administration of the non heme radioisotope 2 capsules with dried sheep red blood cells with 3mg of heme iron intrinsically labeled with 111 kBq of 55Fe will be used
13. Using 20 ml of blood, circulating radioactivity will be measured in accordance with Eakins and Brown double radioisotope technique (1966). 55Fe and 59Fe (NEN, Life Science Products, Inc., Boston, MA) will be quadrupled.
14. Iron status: 10 ml blood used to measure the following, hemoglobin (Hb), mean corpuscular volume (MCV) (CELL-DYN 1700, ABBOTT Diagnostics, Abbott Park, IL CEll Dyn), Zn protoporphyrin (Znpp) (Hematofluorometry ZP-M206D, AVIV Biomedical Inc., Lakewood, NJ)
15. Serum ferritin (SF) by an enzyme immuno assay of double sandwich (INACG)
16. Transferrin receptor (sTrF) and hepcidin by enzyme-linked immunosorbent assay (ELISA) (BioVendor, Laboratorní Medicína AS, Modrice, Czech Republic)
17. Serum iron, total iron binding capacity (TIBC) and transferrin saturation (Fisher and Price)
18. Anthropometry: Weight and height will be measured and compared with the patterns elaborated by World Health Organisation (WHO)
19. Weight will be measured on a digital scale SECA ® with an accuracy of 0.1 kg, and length will be measured with a stadiometer of the same brand with an accuracy of 0.1 cm. 20. With these measurements body mass index (BMI) will be calculated as weight in kilograms divided by height (kg/m2)
21. Weight and height will be used to determine blood volume using the table designated by Tulane
22. Dietary calcium and iron daily intake: at the beginning of the study, three 24 hour recall will be administered each time, on different days in order to estimate calcium and iron daily intake
23. Micronutrients calculation will be performed according to the recommended daily allowance (RDA) for childbearing age women (Food and Nutrition Board)

Intervention type

Supplement

Phase

Not Applicable

Drug names

Calcium supplements

Primary outcome measures

1. Heme iron bioavailability
2. Non heme iron bioavailability

Secondary outcome measures

1. Iron status
1.1. Hemoglobin
1.2. Mean corpuscular volume
1.3. Zn protoporphyrin
1.4. Serum ferritin
1.5. Total iron binding capacity
1.6. Serum Iron
1.7. Hepcidin
1.8. Transferrin Receptor
1.9. Transferrin Saturation
1.10. Total body iron
2. Nutritional state by anthropometry
3. Dietary calcium and iron daily intake

Overall trial start date

15/06/2011

Overall trial end date

30/08/2011

Reason abandoned

Eligibility

Participant inclusion criteria

1. Apparently healthy women
2. Thirty five to 45 years old
3. Not participating in other clinical studies
4. Contraceptive use

Participant type

Patient

Age group

Adult

Gender

Female

Target number of participants

28 women (14 will receive a calcium supplement and 14 a placebo)

Participant exclusion criteria

1. Morbidity (excepting anemia defined as hemoglobin < 120 g/L)
2. Daily use of medicaments
3. Pregnancy and pregnant interest (including a pregnancy test before the start of the study)
4. Breastfeeding
5. Iron and/or calcium supplementation
6. Postmenopausal women
7. Participation in previous studies particularly involving the administration of radioactive labeled iron
8. Smoking

Recruitment start date

15/06/2011

Recruitment end date

30/08/2011

Locations

Countries of recruitment

Chile

Trial participating centre

Institute of Nutrition and Food Technology (INTA)
Santiago
7830489
Chile

Sponsor information

Organisation

University of Chile (Chile)

Sponsor details

Institute of Nutrition and Food Technology (INTA)
El Líbano 5540
Macul
Santiago
7830489
Chile
fpizarro@inta.uchile.cl

Sponsor type

University/education

Website

http://www.uchile.cl/

Funders

Funder type

Research council

Funder name

Chilean Science Council (Fondo de Desarrollo Científico y Tecnológico) [FONDECYT] (Chile) (ref:1095038)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2014 results in: http://www.ncbi.nlm.nih.gov/pubmed/24290597

Publication citations

  1. Results

    Ríos-Castillo I, Olivares M, Brito A, de Romaña DL, Pizarro F, One-month of calcium supplementation does not affect iron bioavailability: a randomized controlled trial., Nutrition, 2014, 30, 1, 44-48, doi: 10.1016/j.nut.2013.06.007.

Additional files

Editorial Notes