ISRCTN - ISRCTN28836000: The Bakary Dibba Study (BDS): Effect of calcium supplementation on growth and bone mineral accretion in Gambian children accustomed to a low calcium diet

Plain English Summary

Background and study aims
Rural Gambian children have poor growth, delayed puberty, a low bone mineral content, and a very low calcium intake. In this study we are investigating the short and long term effects of calcium supplementation.

Who can participate?
160 children (80 boys, 80 girls) aged 8-12 years old, living in the village of Keneba, in the West Kiang district of The Gambia.

What does the study involve?
Participants are randomly allocated to receive either calcium supplements or matched placebo (dummy) tablets five days a week for a year. We will collect blood and urine samples and measure dietary intake, bone minerals, growth, weight and height and body composition.

What are the possible benefits and risks of participating?
Not provided at time of registration.

Where is the study run from?
The Elsie Widdowson Laboratory (UK).

When is the study starting and how long is it expected to run for?
January 1995 to December 2012.

Who is funding the study?
Medical Research Council (UK).

Who is the main contact?
Dr Ann Prentice
ann.prentice@mrc-hnr.cam.ac.uk

Trial website

Contact information

Type

Scientific

Primary contact

Dr Ann Prentice

ORCID ID

Contact details

MRC Human Nutrition Research
Elsie Widdowson Laboratory
Fulbourn Road
Cambridge
CB1 9NL
United Kingdom
+44 (0)122 342 6356
ann.prentice@mrc-hnr.cam.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Short and long term effects of a randomised placebo-controlled calcium supplementation study in Gambian children aged 8-12 years accustomed to a low calcium diet

Acronym

BDS

Study hypothesis

An increase in calcium intake by pre-pubertal children accustomed to a low calcium diet will increase growth and bone moneral accretion

Ethics approval

The study was approved by the joint MRC / Gambian Government ethics committee in 1994, ref no SCC 605

Study design

Randomised double-blind single-centre placebo-controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Other

Trial type

Treatment

Patient information sheet

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

Condition

Osteoporosis

Intervention

Participants were stratified by sex and randomly assigned to receive a calcium supplement or placebo. The randomisation procedure was conducted by a member of staff in Cambridge UK who was not involved in the data collection. The participants and the field and laboratory staff have remained unaware of the assignments throughout the study.

Children were selected in descending age order until the target numbers were achieved. Four children started the study each week to allow recruitment to be spread over a calendar year. Assignment to group was by a randomised permuted block of four to ensure that an equal number of participants was allocated to the calcium and placebo groups each week, to minimise the potential for seasonal confounding.

The calcium supplement consisted of two chewable calcium carbonate tablets (Calcichew®; Shire Pharmaceuticals Ltd, Andover, UK and Nycomed Pharma AS, Oslo) containing 500 mg elemental calcium/tablet. The placebo consisted of similar tablets, produced by the manufacturer of the calcium tablets.

Each participant received either the calcium supplement or the placebo for 5 days each week for 12 months, starting the week after baseline measurements were taken. The tablets were dispensed to the participants at a centrally located building in the village and were consumed in the early evenings under strict supervision.

Follow-up measurements were made 12 and 24 months after the withdrawal of the supplement, and continue to be made regularly throughout late childhood, adolescence and early adulthood. For girls who have started a family, measurements are made during and after lactation.

Intervention type

Supplement

Phase

Drug names

Primary outcome measure

1. Bone mineral status measures [initially forearm single photon absorptiometry (SPA), then whole-body and regional dual energy X-ray absorptiometry (DXA)] at 0, 12, 24, 36 months and regular intervals to adulthood
2. Anthropometry (height, weight, mid upper arm circumference, triceps skinfold) at 0, 12, 24, 36 months and regular intervals to adulthood

Secondary outcome measures

1. Biochemical markers of calcium and bone metabolism measured in blood and urine at 0, 12, 24, 36 months and regular intervals to adulthood
2. Body composition measures (whole-body DXA) from 36 months to adulthood
3. Radial and tibial bone and muscle measures by peripheral quantitative computed tomography (pQCT) in early aldulthood

Overall trial start date

01/01/1995

Overall trial end date

31/12/2012

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

1. Children aged 8-12 years old living in the rural village of Keneba, West Kiang, The Gambia.
2. Healthy, with no history of any medical condition known to affect calcium or bone metabolism
3. No recent fracture
4. Non-consumer of alcohol, antacids, calcium or other nutritional supplements
5. Non-smokers
6. Girls not on contraceptive pills

Participant type

Patient

Age group

Child

Gender

Both

Target number of participants

80 boys and 80 girls

Participant exclusion criteria

Does not meet inclusion criteria

Recruitment start date

01/01/1995

Recruitment end date

31/12/2012

Locations

Countries of recruitment

Gambia

Trial participating centre

MRC Human Nutrition Research
Cambridge
CB1 9NL
United Kingdom

Sponsor information

Organisation

MRC Human Nutrition Research (UK)

Sponsor details

Elsie Widdowson Laboratory
Fulbourn Road
Cambridge
CB1 9NL
United Kingdom

Sponsor type

Research council

Website

Funders

Funder type