Vitamin D Intervention Trial in Healthy Chinese

Study Overview
=================
Brief Summary
-----------------
To determine the dose-response between the doses of vitamin D3 supplements and raised serum levels of 25(OH)D and also the dose of vitamin D3 required to achieve circulating 25(OH)D ≥ 75 nmol/L;

Detailed Description
-----------------
Recent epidemiological studies suggested that serum 25-hydroxyvitamin D [25(OH)D] concentration ≥75 nmol/L appeared to be optimal for preventing cardiometabolic diseases and improving bone health. To achieve this goal, a daily intake of 1000 IU or equivalent amount from other sources, is needed, which is twice as much as the RDA recommended by Chinese Nutrition Society. Meanwhile,epidemiological evidences show that large proportions of Chinese may suffer vitamin D insufficiency or deficiency whereas the current RDA in China might be too low to provide adequate vitamin D for people's health. In order to fill up this gap, therefore, it is essential to determine the dose-response between the doses of vitamin D3 supplements and raised serum levels of 25(OH)D and also the dose of vitamin D3 required to achieve circulating 25(OH)D ≥ 75 nmol/L.Ultimately, the current study will provide important evidence for establishing optimal vitamin D requirement for Chinese people

Official Title
-----------------
Knowledge Innovation Project of CAS - Genetic and Nutritional Association Studies on Metabolism-related Diseases in Chinese Population -- Vitamin D Intervention Study：A Pilot Study

Conditions
-----------------
Vitamin D Deficiency

Intervention / Treatment
-----------------
* Dietary Supplement: Placebo
* Dietary Supplement: Vitamin D


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Age: 20-45 years. with vitamin D deficiency (25(OH)D < 50 nmol/l) Exclusion Criteria: BMI < 18.5 kg/m2, or BMI ≥ 25 kg/m2 Total intake of calcium from diet or supplements >1200mg/d, or fasting serum calcium level ≥2.75 mmol/l Participating in other clinical studies within previous 3 months Taking vitamin D supplements within previous 3 months Using medications that may affect vitamin D metabolism in previous 3 months; Concomitant with clinical conditions, like liver dysfunction (serum alanine transaminase (ALT) ≥40 U/L; and/or aspartate transaminase (AST) ≥40 U/L; Glutamyl transpeptidase （GGT）≥50 U/L; serum creatinine < 50 or > 120 µmol/L; urea nitrogen (UN) < 7 or > 18 mg/dl, and/or urine acid <90 or >420 µmol/L; which may affect vitamin D metabolism; History of drug or alcohol abuse (>40 g/d) Women during pregnancy or lactation Individuals with mental disorders or current use of antidepressants, the conditions which may affect him or her understanding and unwillingness to the intervention; Having clinically diagnosed AIDS, hepatitis A, hepatitis B, tuberculosis and other infectious diseases.

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>5 placebo pills per day, 16 weeks | Dietary Supplement: Placebo<br>* placebo<br>|
| Experimental: 400 IU<br>(4 placebo pills + 1 vitamin D pill) per day, 16 weeks | Dietary Supplement: Placebo<br>* placebo<br>Dietary Supplement: Vitamin D<br>* 400 IU vitamin D per pill<br>|
| Experimental: 800 IU<br>(3 placebo pills + 2 vitamin D pills) per day, 16 weeks | Dietary Supplement: Placebo<br>* placebo<br>Dietary Supplement: Vitamin D<br>* 400 IU vitamin D per pill<br>|
| Experimental: 1200 IU<br>(2 placebo pills + 3 vitamin D pills) per day, 16 weeks | Dietary Supplement: Placebo<br>* placebo<br>Dietary Supplement: Vitamin D<br>* 400 IU vitamin D per pill<br>|
| Experimental: 2000 IU<br>5 vitamin D pills per day, 16 weeks | Dietary Supplement: Vitamin D<br>* 400 IU vitamin D per pill<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 25-hydroxyvitamin D | Serum 25(OH)D concentration will be assayed by utilizing a liquid chromatography-mass spectrometry (LC-MS) method | 16 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| alanine aminotransferase（ALT) | Serum ALT will be measured by an Automatic biochemical analyzer | 16 weeks | 
| aspartate aminotransferase(AST) | Serum AST will be measured by an Automatic biochemical analyzer; | 16 weeks | 
| glutamyl transpeptidase（GGT） | Serum GGT will be measured by an Automatic biochemical analyzer | 16 weeks | 
| creatinine | creatinine will be measured by an Automatic biochemical analyzer | 16 weeks | 
| uric acid | Serum uric acid will be measured by an Automatic biochemical analyzer | 16 weeks | 
| urea nitrogen | Serum urea nitrogen will be measured by an Automatic biochemical analyzer | 16 weeks | 
| calcium | Serum calcium will be measured by an Automatic biochemical analyzer. | 16 weeks | 
| phosphate | Serum phosphate will be measured by an Automatic biochemical analyzer. | 16 weeks | 
| parathyroid hormone（PTH） |  | 16 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
vitamin D, deficiency, dose response