Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

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

Trial website

Contact information



Primary contact

Dr Ann Prentice


Contact details

MRC Human Nutrition Research
Elsie Widdowson Laboratory
Fulbourn Road
United Kingdom
+44 (0)122 342 6356

Additional identifiers

EudraCT number number

Protocol/serial number


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



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


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

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




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



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


Overall trial end date


Reason abandoned (if study stopped)


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


Age group




Target number of participants

80 boys and 80 girls

Participant exclusion criteria

Does not meet inclusion criteria

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

MRC Human Nutrition Research
United Kingdom

Sponsor information


MRC Human Nutrition Research (UK)

Sponsor details

Elsie Widdowson Laboratory
Fulbourn Road
United Kingdom

Sponsor type

Research council



Funder type

Research council

Funder name

Medical Research Council (MRC) (UK)

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

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

Basic results (scientific)

Publication list

2000 results in:
2012 results in:
2014 results in:

Publication citations

  1. Results

    Dibba B, Prentice A, Ceesay M, Stirling DM, Cole TJ, Poskitt EM, Effect of calcium supplementation on bone mineral accretion in gambian children accustomed to a low-calcium diet., Am. J. Clin. Nutr., 2000, 71, 2, 544-549.

  2. Results

    Prentice A, Dibba B, Sawo Y, Cole TJ, The effect of prepubertal calcium carbonate supplementation on the age of peak height velocity in Gambian adolescents., Am. J. Clin. Nutr., 2012, 96, 5, 1042-1050, doi: 10.3945/ajcn.112.037481.

  3. Results

    Ward KA, Cole TJ, Laskey MA, Ceesay M, Mendy MB, Sawo Y, Prentice A, The effect of prepubertal calcium carbonate supplementation on skeletal development in Gambian boys-a 12-year follow-up study, J Clin Endocrinol Metab, 2014, 99, 9, 3169-3176, doi: 10.1210/jc.2014-1150.

Additional files

Editorial Notes