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A dose-response, double-blind, randomised placebo-controlled trial to estimate the dietary requirement for vitamin D in male and female adolescents aged 14-18 years

Completed
Conditions
Topic: Primary Care
Subtopic: Not Assigned
Disease: All Diseases
Nutritional, Metabolic, Endocrine
Registration Number
ISRCTN40736890
Lead Sponsor
niversity of Surrey (UK)
Brief Summary

Not available

Detailed Description

Not available

Recruitment & Eligibility

Status
Completed
Sex
All
Target Recruitment
120
Inclusion Criteria

1. Male or female
2. Aged between 14 and 18 years
3. In good health
4. Written informed consent from the adolescent (and parent if required)

Exclusion Criteria

1. Currently receiving treatment for medical conditions likely to affect vitamin D metabolism
2. Hypercalcaemia (>2.5mmol/l)
3. Regular use of sunbeds
4. Having a sun holiday one month prior to commencing the trial or plans for a sun holiday within the study period.
5. Use of vitamin supplements containing vitamin D ? if the prospective participant agrees to stop vitamin D supplementation to join the study, a washout period of 8 weeks prior to commencing the trial would be acceptable.
6. Excessive consumption of alcohol (>14 units per week for females, >21 units per week for males)
7. Smoking >10 cigarettes per day
8. Those following a weight-reducing diet or under dietary restriction (except vegetarianism)
9. Known intolerance/allergy to the constituent ingredients of the daily supplement
10. Clinically significant haematological abnormalities other than mild anaemia (Hb<12.0g/dl)
11. Active malignancy
12. Pregnant or planning a pregnancy during the study period.

Study & Design

Study Type
Interventional
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Serum 25-hydroxyvitamin D concentrations; Timepoint(s): End of study (20 weeks after supplementation has begun)
Secondary Outcome Measures
NameTimeMethod
ot provided at time of registration
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