Clinical trial NCT00493012: Vitamin D Effects in Overweight Patients
Official title: Effects of a Vitamin D (Cholecalciferol) Supplement on Body Composition, Blood Pressure, and Lipid and Diabetes Parameters in Overweight Patients Attending a Telemedically Guided Weight Loss Program
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Overweight
Obesity
Keywords: body weight
body compostion
vitamin D
blood pressure
Lead sponsor: Heart and Diabetes Center North-Rhine Westfalia
Sponsor class: OTHER
First posted: 2007-06-27
Enrollment: 200
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The purpose of the study is to investigate in overweight patients who are on a telemedically guided weight loss program the influence of a daily vitamin D supplement on

* weight loss and body composition,
* selected inflammation markers and biochemical parameters of lipid and glucose metabolism .
* selected clinical parameters such as blood pressure, heart rate

Detailed description: Obese patients are known to have low levels of vitamin D metabolites. There is some evidence that vitamin D and/or dietary calcium may influence energy metabolism and body weight. We therefore perform a prospective controlled trial with 200 overweight (Body mass index 27-29.9 kg/m2) and obese subjects (Body mass index \>= 30 kg/m2) who are on a telemedically guided weight loss program. Subjects randomly receive a daily vitamin D supplement or a placebo for 1 year. Participants have to send their body weight data to the study office weekly. In addition, a nutritionist at the study office has to be contacted weekly to receive further support concerning the weight loss program. Dietary records have to be completed monthly. Clinical parameters and blood samples are collected at baseline, and after 6 and 12 months. It is the aim of the study to investigate the vitamin D effects on weight loss and body composition. In addition, possible vitamin D effects on clinical and selected biochemical parameters should be assessed. These parameters include heart rate, blood pressure, inflammation markers, and parameters of lipid and glucose metablolism.

Eligibility criteria: Inclusion Criteria:

* Body mass index \> 27 kg/m2

Exclusion Criteria:

* pregnant and lactating women
* vegetarians
* patients with renal insufficiency (creatinine \> 1.5 mg/dl)
* History of renal stones and gallstones
* patients with insulin dependent diabetes mellitus
* parallel participation in another clinical study
* missing informed consent
* subjects with pacemaker implantation

Primary outcomes:
measure: Change in Body Weight From Baseline to 12 Months
timeFrame: baseline, 12 months
Secondary outcomes:
measure: Change in Fat Mass From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in 25-hydroxyvitamin D From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Calcitriol From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Parathyroid Hormone From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Triglycerides From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in LDL-cholsterol From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in C-reactive Protein From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Tumor Necrosis Factor Alpha From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Proinsulin From Baseline to 12 Months
timeFrame: baseline, 12 months
measure: Change in Hb A1c From Baseline to 12 Months
timeFrame: change from baseline to 12 months
Other outcomes:
Locations:
city: Bad Oeynhausen
country: Germany
facility: Heart and Diabetes Center NRW
state: North-Rhine Westfalia
Study officials:
affiliation: Institute of Applied Telemedicine, Heart and Diabetes Center North-Rhine Westfalia, 32545 Bad Oeynhausen, Germany
name: Heinrich Koertke, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Zittermann A, Frisch S, Berthold HK, Gotting C, Kuhn J, Kleesiek K, Stehle P, Koertke H, Koerfer R. Vitamin D supplementation enhances the beneficial effects of weight loss on cardiovascular disease risk markers. Am J Clin Nutr. 2009 May;89(5):1321-7. doi: 10.3945/ajcn.2008.27004. Epub 2009 Mar 25.