Vitamin D Supplementation and PTH Response Among Malaysian Adults

Study Overview
=================
Brief Summary
-----------------
This clinical trial was designed to determine the efficacy of vitamin D supplementation on plasma 25-hydroxyvitamin D [25(OH)D] and intact parathyroid hormone (PTH) concentrations of Malaysian female adults of child-bearing age after daily intake of vitamin D supplements containing either 0 IU, 600 IU, 1200 IU or 4000 IU vitamin D for 16 weeks.

Detailed Description
-----------------
After being informed regarding the study protocol and requirements, participants given informed consent were interviewed using a questionnaire for collection of background data and medical history as a screening process. Eligible participants were randomly assigned in a double-blind manner to receive daily 500 mg of calcium with either 0, 600 IU, 1200 IU or 4000 IU vitamin D supplement for 16 weeks. Questionnaires and anthropometric measurements were collected at baseline and post 16 weeks supplementation trial. Primary outcomes of plasma 25(OH)D and intact PTH were measured via fasting intravenous blood samples at baseline and post 16 weeks trial.

Official Title
-----------------
Vitamin D Supplementation, Parathyroid Hormone (PTH) and Plasma Vitamin D Response Among Malaysian Female Adults: Double Blinded, Randomised Clinical Trial of Efficacy

Conditions
-----------------
Healthy

Intervention / Treatment
-----------------
* Dietary Supplement: Placebo, 500 mg calcium
* Dietary Supplement: 600 IU vitamin D + 500 mg calcium
* Dietary Supplement: 1200 IU vitamin D + 500 mg calcium
* Dietary Supplement: 4000 IU vitamin D + 500 mg calcium


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: three major ethnic groups (Malay, Chinese, Indian) age 20-45 years Exclusion Criteria: any diseases or conditions that may affect vitamin D metabolism, such as diabetes, cardiovascular diseases, bone diseases, autoimmune diseases, had major gastrointestinal surgery and diagnosed primary hyperparathyroidism medications that might affect vitamin D metabolism, such as insulin, thiazide diuretics, prednisolone, biphosphonates, tamoxifen and phenytoin pregnant and lactating women

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

Sexes Eligible for Study
-----------------
Female

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

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

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo, 500 mg calcium<br>Participants received 500 mg calcium in berry flavoured sachet powder daily for 16 weeks | Dietary Supplement: Placebo, 500 mg calcium<br>* Berry flavoured sachet powder (500 mg calcium)<br>Dietary Supplement: 600 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (600 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 1200 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (1200 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 4000 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (4000 IU vitamin D + 500 mg calcium)<br>|
| Active Comparator: 600 IU vitamin D + 500 mg calcium<br>Participants received 600 IU vitamin D with 500 mg calcium in berry flavoured sachet powder daily for 16 weeks | Dietary Supplement: Placebo, 500 mg calcium<br>* Berry flavoured sachet powder (500 mg calcium)<br>Dietary Supplement: 600 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (600 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 1200 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (1200 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 4000 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (4000 IU vitamin D + 500 mg calcium)<br>|
| Active Comparator: 1200 IU vitamin D + 500 mg calcium<br>Participants received 1200 IU vitamin D with 500 mg calcium in berry flavoured sachet powder daily for 16 weeks | Dietary Supplement: Placebo, 500 mg calcium<br>* Berry flavoured sachet powder (500 mg calcium)<br>Dietary Supplement: 600 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (600 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 1200 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (1200 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 4000 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (4000 IU vitamin D + 500 mg calcium)<br>|
| Active Comparator: 4000 IU vitamin D + 500 mg calcium<br>Participants received 4000 IU vitamin D with 500 mg calcium in berry flavoured sachet powder daily for 16 weeks | Dietary Supplement: Placebo, 500 mg calcium<br>* Berry flavoured sachet powder (500 mg calcium)<br>Dietary Supplement: 600 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (600 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 1200 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (1200 IU vitamin D + 500 mg calcium)<br>Dietary Supplement: 4000 IU vitamin D + 500 mg calcium<br>* Berry flavoured sachet powder (4000 IU vitamin D + 500 mg calcium)<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline plasma 25-hydroxyvitamin D at week 16 | 5ml of fasting blood sample were taken by venepuncture into heparin tubes. Collected blood samples were centrifuged at 4000 rpm for 10 minutes, extracted plasma and stored at -80˚C until sent for analysis | Baseline and week 16 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline intact parathyroid hormone at week 16 | 5ml of fasting blood sample were taken by venepuncture into heparin tubes. Collected blood samples were centrifuged at 4000 rpm for 10 minutes, extracted plasma and stored at -80˚C until sent for analysis | Baseline and week 16 |