Comparing Different Amounts of Vitamin D Supplementation to Preschool Children Living in Northern and Southern Sweden

Summary

Vitamin D has a range of biological effects of public health relevance. Vitamin D status is assessed on levels of its metabolite 25-hydroxyvitamin D \[25(OH)D\], where levels \< 50 nmol/L indicate insufficiency. Despite studies indicating that the vitamin D intake among Swedish children are significantly below recommendations, little is known of their vitamin D status. The investigators have recently found inadequate vitamin D status in pre-school children living in northern Sweden, especially in dark-skinned children and during the winter months despite vitamin D intakes meeting the recommendations. Overall, 25% of the light skinned and 40% of the dark skinned children had S-25(OH) D \<50 nmol/L (Öhlund I, unpublished data). The aim is to examine which amount of vitamin D is needed to maintain or increase S-25(OH)D to ≥50 nmol/L among 97.5% of the participants regardless of skin color or geographic location (northern or southern Sweden). Furthermore the investigators will examine if vitamin D status affects on health markers as bone density, blood pressure, serum lipids, fatty acids, inflammatory and immunological markers and mental wellbeing.

Children aged 5-8 years living either northern (Umeå) or southern Sweden (Malmö) will be recruited to this trial during November-December 2012. They will be randomized to a vitamin D supplement of either 10 or 25 g per day, or in Malmö also placebo to be used for three months. The randomization will be stratified according to skin color (light or dark) according to a method using visual inspection and interviews of parents/guardians. The investigators will use a 2×2×2 factorial design to investigate the effects of two different doses of vitamin D (10 µg and 25 µg) in children with dark and light skin color, living in northern (Umeå) and southern (Malmö), Sweden. In order to achieve a moderate difference between groups (effect size 0.25) 20 children per group are required (power\> 87%, alpha = 0.05). With an estimated dropout of 10%, a total of 220 children will be included.

At baseline, the participants will undergo blood sampling for S-25(OH)D and other biomarkers, blood pressure and anthropometrical measurements, including bone densitometry and body composition using air displacement pletysmography, and the parents will answer a questionnaire on behavioral and emotional problems in the participating child using the Child Behavior Checklist. These measurements will be repeated at follow-up in February-March 2013.

Conditions

• Vitamin D Deficiency

Interventions

DIETARY_SUPPLEMENT

Vitamin D 25 microg/d

The vitamin D supplement will be provided as a milk drink taken daily.

DIETARY_SUPPLEMENT

Vitamin D 10 microg/d

The vitamin D supplement will be provided as a milk drink taken daily.

DIETARY_SUPPLEMENT

No extra vitamin D

Milk drink with no extra vitamin D (placebo)

Sponsors & Collaborators

• Region Skane

  collaborator OTHER

• Umeå University

  lead OTHER

Principal Investigators

• Inger Öhlund, Ph.D. · Umeå University

• Torbjörn Lind, M.D., Ph.D. · Umeå University

• Pia Karlsland-Åkesson, M.D., Ph.D. · University hospital, Malmö/Lund

• Sven-Arne Silfverdal, M.D., Ph.D. · Umeå University

• Olle Hernell, M.D., Ph.D. · Umeå University

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Model

FACTORIAL

Eligibility

Min Age

5 Years

Max Age

7 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2012-11-30

Primary Completion

2013-04-30

Completion

2013-07-31

Countries

• Sweden

Study Locations