Vitamin D Supplementation in Conscripts

Vitamin D Deficiency Clinical Trial

Official title:

Fitness and Health Characteristics in Conscripts With Supplementation of Vitamin D

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04359524
• Other study ID #: R-002
• Status: Completed
• Phase: N/A
• Start date: October 1, 2016
• Est. completion date: April 25, 2017

Study information

• Verified date: September 2021
• Source: Tartu University Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A longitudinal, triple-blinded, randomized, placebo-controlled trial, with a 7-month follow-up period is conducted between October 2016 to April 2017.

Description:

Body mass (kg) and height (cm) is measured by the same person at the medical center using standardized equipment and the body mass index (BMI) is calculated in kg/m2.

Computed randomization is used to divide conscripts into two groups; either the intervention group or the control group. Both types of capsules are administered once per day in the morning before breakfast for 7 months. Standardized coded packages (3 per conscript) and capsules (100 per package) are manufactured on a special order by Innopharma A/S (Denmark). No commercial sponsoring is involved.

The key of the package code is stored in the computer database until unblinding of the results.

Laboratory measurements Serum samples for clinical chemistry analysis are collected into serum clot activator tubes. Calcium measurements are performed using spectrophotometry method. Ionized calcium measurements are performed using ion selective electrodes. The direct chemiluminescent immunoassay method is used for measurement of PTH. 25(OH)D is measured using direct chemiluminescent immunoassay method.

Power calculation The primary variable of the study is the level of 25 (OH)D in the serum. In the power analysis a difference of 20 nmol/L between the intervention and the control group is considered to be meaningful to detect. If the SD would be 25 nmol/L, then 26 participants would be needed in each group to reach a power of 80%.

Statistical analysis The distribution of blood serum values in the study groups is described by means and standard deviations (SD). Differences in mean values of the variables of interest between the groups are evaluated using Welch t-test. The within group comparisons over time are performed using paired t-test with Bonferroni correction. Distributions of categorical variables are described by absolute numbers and percentages and compared between groups using the Fisher exact test. Statistical significance is set at the 0.05 probability level.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 63
• Est. completion date: April 25, 2017
• Est. primary completion date: April 20, 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 19 Years to 27 Years

Eligibility

Inclusion Criteria:

• participating in military service at the Estonian Defence Forces

• voluntarity to participate in the study

Exclusion Criteria:

• inability to continue military service for any reason, during the 7 month follow-up period

Related Conditions & MeSH terms

• Military Activity
• Vitamin D Deficiency

Intervention

Dietary Supplement:
• Vitamin D3 (1200 IU/30µg)

• Placebo
Placebo oil capsule

Locations

Country	Name	City	State
Estonia	Kuperjanov Infantry Battalion, Estonian Defence Forces	Võru	Võrumaa

Sponsors (3)

Lead Sponsor	Collaborator
Leho Rips	Estonian Defence Forces, University of Tartu

Country where clinical trial is conducted

Estonia, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	serum parathyroid hormone	serum parathyroid hormone concentration (pmol/l)	0, 2, 5 and 7 months of recruitment
Other	serum calcium	serum calcium (Ca) concentration (mmol/l)	0, 2, 5 and 7 months of recruitment
Other	serum ionized calcium	serum ionized calcium (Ca-i) concentration (mmol/l)	0, 2, 5 and 7 months of recruitment
Other	Hand Grip Strength	Hand grip strength is determined by isometric contraction while standing, upper limb away from the body, using a hand dynamometer (Lafayette Instrument Co., USA).	0, 2, 5 and 7 months of recruitment
Other	Testosterone	Serum testosterone concentration (nmol/l)	0, 2, 5 and 7 months of recruitment
Other	Cortisol	Serum cortisol concentration (nmol/l)	0, 2, 5 and 7 months of recruitment
Primary	Prevalence of vitamin D deficence	Prevalence of vitamin D deficence as measured serum vitamin D 25(OH)D concentration. Vitamin D was considered as sufficient if the se-rum 25(OH)D concentration was =75 nmol/L, insufficient if <75 nmol/L, and deficient if <50 nmol/L.	0, 2, 5 and 7 months of recruitment