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The Role of Vitamin D Supplementation on Well Being and Symptoms of Depression During the Winter Season in Health Service Staff (D3-vit-SAD)

This study has been completed.
Information provided by (Responsible Party):
Connie Thuree Nielsen, consultant, MD, ph.d, Region Syddanmark Identifier:
First received: October 26, 2011
Last updated: March 28, 2012
Last verified: March 2012
The purpose of this study is to investigate whether vitamin D3 (70 micrograms) is better than placebo in preventing depression symptoms among employees in health care

Condition Intervention Phase
Seasonal Affective Disorder
Vitamin D3
Mental Health
Dietary Supplement
Dietary Supplement: Vitamin D3
Drug: Placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention

Resource links provided by NLM:

Further study details as provided by Connie Thuree Nielsen, consultant, MD, ph.d, Region Syddanmark:

Primary Outcome Measures:
  • Hamilton-29 [ Time Frame: 12 weeks ]
    Change from baseline in Hamilton-29 at week 12

Secondary Outcome Measures:
  • WHO-5 [ Time Frame: 12 weeks ]
    Change from baseline in WHO-5 at week 12

Enrollment: 50
Study Start Date: October 2011
Study Completion Date: March 2012
Primary Completion Date: March 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Vitamin D3
one tablet of vitamin D3 (70µg) per day for 12 weeks.
Dietary Supplement: Vitamin D3
70µg Vitamin D3, daily, 12 weeks
Other Name: Active
Placebo Comparator: placebo
one tablet of sugar pill per day for 12 weeks.
Drug: Placebo
Placebo, daily, 12 weeks

Detailed Description:

Vitamin D3 is produced in the skin after exposure to ultraviolet B light from the sun. Vitamin D3 is metabolised sequential in the liver into 25-hydroxy-vitamin D [25(OH)D], which is the storage form of vitamin D in the body, and then in the kidney into the steroid hormone, 1a,25-dihydroxyvitamin 1a,25-dihydroxyvitamin D [1,25(OH)2D].

At higher latitudes ultraviolet B light is stopped by the atmosphere during winter season. Half of Danes have low levels of [25(OH)D] in the blood and especially in the early spring months the levels of [25(OH)D] are low. In addition, Vitamin D3 is absorbed through the gut from vitamin D-rich food sources. But several studies show that it is not possible through a recommended diet, which consists of 300 g of fish per week to consume adequate amounts of vitamin D3.

New research suggests link between vitamin D3 and brain function.In the Central Nervous System (CNS) there are specific nuclear receptors for 1,25(OH)2D (VDR) and the enzymes necessary for the hydroxylation of 25(OH)D to 1,25(OH)2D are also present in CNS.

In clinical studies, low serum levels of 25(OH)D, have been associated with reduced cognitive function, anxiety and depression.

The objective of this randomized clinical trial is to investigate whether indoor employees, with tendency to depressive symptoms in the winter season, should be offered vitamin D3 supplements during the Winter season, or it has no significance in relation prevent depressive symptoms.

The study is carried out in the winter season in the Region of Southern Denmark for 12 weeks and offered to health service staff, who have a tendency for depressive symptoms in the winter season.


Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Health service staff and employee in the Region of Southern Denmark.
  • Tendency to depressive symptoms in the winter season SPAQ>7.

Exclusion Criteria:

  • clinical diagnosis sarcoidoses
  • tuberculosis
  • bipolar affective disorder
  • schizophrenia
  • hypercalcemia
  • hyperphosphatemia
  • pregnancy
  • hyperparathyroidism
  • reduced kidney function
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01462058

Mental Health Services Esbjerg
Esbjerg, Esbjerg N, Denmark, 6715
Sponsors and Collaborators
Connie Thuree Nielsen, consultant, MD, ph.d
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Connie Thuree Nielsen, consultant, MD, ph.d, MD, ph.d, Region Syddanmark Identifier: NCT01462058     History of Changes
Other Study ID Numbers: ID-301115
Study First Received: October 26, 2011
Last Updated: March 28, 2012

Keywords provided by Connie Thuree Nielsen, consultant, MD, ph.d, Region Syddanmark:
Hamilton 29
Vitamin D3

Additional relevant MeSH terms:
Mood Disorders
Seasonal Affective Disorder
Mental Disorders
Depressive Disorder
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on May 25, 2017