WithdrawnNCT02422784VITD-2013Updated Feb 23, 2017

Effects of Vitamin D Fortification on Vitamin D Metabolite Profiles and Status in Vitamin D Insufficient Individuals

A Phase 1 interventional study of Rooibos Iced-Tea (Control) and Rooibos Tea - Vitamin D3 in Vitamin D Deficiency, sponsored by University of Manitoba. Withdrawn at 1 site in Canada. Open to participants aged 19 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-02-23.

Sponsored by University of Manitoba · Phase 1, Interventional, and Treatment

Phase: Phase 1
Study type: Interventional
Enrollment: 0
Allocation: Randomized
Ages: 19 Years to 50 Years
Sex: All

Study summary

This is a cross-sectional study designed to compare plasma/serum and urine vitamin D metabolite profiles of vitamin D sufficient and insufficient individuals.

There are two phases of this study.

Phase 1 - Consented study participants will attend a screening visit and provide a fasting blood and urine sample. Those individuals who are vitamin D insufficient based on serum 25(OH)D concentrations will be invited to participate in Phase II

Phase II - is a double-blind, randomized, control study designed to examine vitamin D status in vitamin D insufficient individuals consuming a water-soluble form of vitamin D3. Eligible participants will be asked to consume one of three beverages: i) rooibos iced-tea (control); ii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3; or iii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3 and 360 mg calcium at 240 mL of iced-tea consumed daily for 6 weeks. Participants will attend 6 weekly visits following baseline and provide a fasting blood sample for assessment of serum 25(OH)D concentrations.

Objectives: 1) To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals; and 2) To determine the effects of vitamin D3 fortification on serum 25-dihydroxy-vitamin D [25(OH)D] concentrations, markers of vitamin D and calcium metabolism, and vitamin D metabolite profile in plasma/serum and urine of vitamin D insufficient individuals.

Read the detailed description

Health individuals from the general public will be recruited into this cross-sectional study designed to compare plasma/serum and urine vitamin D metabolite profiles of those identified as vitamin D sufficient and insufficient individuals.

There are two objectives:

Objective 1: To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals; N=20 and will consist of 10 individuals identified as vitamin D insufficient and 10 individuals identified as vitamin D deficient individuals.

Objective 2: To determine the effects of vitamin D3 fortification on serum 25-dihydroxy-vitamin D [25(OH)D] concentrations, markers of vitamin D and calcium metabolism, and vitamin D metabolite profile in plasma/serum and urine of vitamin D insufficient individuals. N=45.

To achieve the objectives, the study will be conducted in two phases:

Phase 1 - Healthy males or females, ≥19 and ≤50 years of age, will be recruited from the general public. Consented study participants will provide a fasting blood and urine sample for the purpose of determination of vitamin D status (insufficient vs. deficient) based on serum 25(OH)D concentrations. Forty-five (45) individuals identified as vitamin D insufficient (having a serum 25(OH)D concentration ≥30 and ≤75 nmol/L) will proceed to phase II. A N=20 (10 vitamin D insufficient and 10 vitamin D deficient) will also be identified to satisfy objective 1.

Phase II - is a double-blind, randomized, control study designed to examine vitamin D status in vitamin D insufficient individuals consuming a water-soluble form of vitamin D3. Eligible participants will randomized to consume one of three beverages: i) rooibos iced-tea (control); ii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3; or iii) rooibos iced-tea fortified with 1000 IU of water-soluble vitamin D3 and 360 mg calcium at 240 mL of iced-tea consumed daily for 6 weeks. Both researchers and participants will be blinded to the beverage group assigned to each participant. Participants will then attend 6 weekly visits following the baseline visit to provide fasting blood samples for assessment of serum 25(OH)D concentrations.

Analysis of intact-PTH, alkaline-phosphatase, calcium, phosphorus, CRP, TAP and vitamin D metabolite profile and a urine sample will also be obtained for assessment of N-telopeptide and vitamin D metabolite profile will also occur at Baseline and Week 6. Fasting blood samples collected at week 3 will be used for additional assessment of serum alkaline phosphatase, calcium and phosphorus. A 3-day Food Record will be provided at week 3.

Vitamin D insufficient participants will be stratified according to their serum 25(OH)D concentrations (≥30 and ≤50, or >50 and ≤75 nmol/L) after screening and prior to the beverage study to ensure that a range of lower and higher serum 25(OH)D concentrations are represented in each beverage group.

Conditions studied

Vitamin D Deficiency

Browse trials for

Vitamin D Deficiency 772

Keywords

Vitamin D insufficient
rooibos tea
calcium

In context

Vitamin D Deficiency

772 studies on the registry are indexed under Vitamin D Deficiency; 61 are open to participants now.

Browse Vitamin D Deficiency studies →

Lead sponsor

University of Manitoba is the lead sponsor of 542 studies on the registry; 87 are open to participants now.

Of its 12 completed or terminated interventional studies of FDA-regulated products, 5 (42%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 19 Years to 50 Years
Sexes eligible: All
Accepts healthy volunteers: Yes

Inclusion criteria

A. Inclusion Criteria for Objective 1 (Part One):

Adult volunteers, male or female, between 19 and 50 years of age;
Body mass index (BMI) ≥20 and ≤30 kg/m2 (normal to overweight);
Must be on a stable regime for the past three months, if taking vitamin and mineral/dietary/herbal supplements; and
Willing to provide informed consent.

B. Inclusion Criteria for Objective 2 (Part Two):

Adult volunteers, male or female, between 19 and 50 years of age;
Body mass index (BMI) ≥20 and ≤30 kg/m2 (normal to overweight);
Must be on a stable regime for the past three months, if taking vitamin and mineral/dietary/herbal supplements;
Vitamin D insufficient (serum 25(OH)D concentrations ≥30 and ≤75 nmol/L);
Willing to comply with protocol requirements; and
Willing to provide informed consent.

Exclusion criteria

Exclusion Criteria:

Take a vitamin D or calcium supplement within the last three months before the start date of the study, or during the study;
History of vitamin D deficiency (serum 25(OH)D concentration \<30 nmol/L);
History of hypocalcaemia;
Presence of a clinically diagnosed disease affecting the circulatory, respiratory, immune, skeletal, urinary, muscular, endocrine, digestive, nervous or reproductive system that requires medical treatment;
Taking any medication (with the exception of birth control);
Daily consumption of more than three servings of dairy products;
Undergone significant sun exposure one month before start date of the study;
Use or have used a tanning booth one month before start date of the study, or during the study;
Plan to travel to a sunny climate during the study;
Currently smoking or have smoked within the last six months before start date of the study, or during the study;
Have allergies to tea products;
Pregnant or lactating; and
Consume excessive alcohol (>10 drinks/week for women, >15 drinks/week for men).

Study design

Phase: Phase 1
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: Double (Participant, Investigator)
Enrollment: 0 participants (actual)

Study arms

Placebo comparator
Control
Participants will be instructed to consume 240 mL of iced-tea daily for 6 weeks. The iced-tea beverages do not contain added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.
Dietary Supplement: Rooibos Iced-Tea (Control)
Active comparator
Rooibos Tea - Vitamin D3
Participants will be instructed to consume 240 mL of iced-tea fortified with 1000 IU water-soluable vitamin D3 daily for 6 weeks. The iced-tea beverages do not contain added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.
Dietary Supplement: Rooibos Tea - Vitamin D3
Active comparator
Rooibos Tea- Vitamin D3 & Calcium
Participants will be instructed to consume 240 mL of Rooibos iced-tea fortified with 1000 IU of water-soluable vitamin D3 and 360 mg of calcium daily for 6 weeks. The iced-tea beverages do not contain added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.
Dietary Supplement: Rooibos Tea- Vitamin D3 & Calcium

Interventions

Dietary supplementRooibos Iced-Tea (Control)
Participants will consume 240 mL of Rooibos iced-tea daily for 6 weeks. The iced-tea beverage will not contain any added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.
Dietary supplementRooibos Tea - Vitamin D3
Participants will consume 240 mL of Rooibos iced-tea fortified with 1000 IU of water soluable Vitamin D3 daily for 6 weeks. The iced-tea beverage will not contain any added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.
Dietary supplementRooibos Tea- Vitamin D3 & Calcium
Participants will consume 240 mL of Rooibos iced-tea fortified with 1000 IU of water soluable Vitamin D3 and 360 mg of Calicum daily for 6 weeks. The iced-tea beverage will not contain any added sugar or artificial sweeteners. Beverages will be prepared fresh weekly and picked up by participants during their weekly study visits.

What researchers measure

Primary outcomes

Plasma/Serum and Urine Vitamin D Metabolite Profiles of Vitamin D Sufficient and Insufficient Individuals
To investigate plasma/serum and urine vitamin D metabolite profiles in vitamin D sufficient and insufficient individuals.
Time frame: Screening Visit (Day 0) - Phase 1
The Effects of Vitamin D Fortification on Serum 25(OH)D in Vitamin D Insufficient Individuals.
To determine the effects of 6 weeks of vitamin D3 fortification on serum 25-dihydroxy-vitamin D \[25(OH)D\] concentrations of vitamin D insufficient individuals.
Time frame: 6 Weeks (Phase II)

Secondary outcomes

The Effects of Vitamin D3 Fortification on markers of vitamin D of vitamin D insufficient individuals
To determine the effects of 6 weeks of vitamin D3 fortification on markers of vitamin D in plasma/serum and urine of vitamin D insufficient individuals.
Time frame: 6 Weeks (Phase II)
The Effects of vitamin D3 Fortification on calcium metabolism of Vitamin D Insufficient Individuals.
To determine the effects of 6 weeks of vitamin D3 fortification on calcium metabolism in plasma/serum and urine of vitamin D insufficient individuals.
Time frame: 6 Weeks (Phase II)
The Effects of Vitamin D3 Fortification on Vitamin D Metabolite Profile of Vitamin D Insufficient Individuals.
Determine the effects of vitamin D3 fortification on the vitamin D metabolite profile in plasma/serum and urine of vitamin D insufficient individuals.
Time frame: 6 Weeks (Phase II)

Study locations

1 site

St. Boniface Hospital, Asper Clinical Research Institute
Winnipeg, Manitoba R2H 2A6, Canada

References and documents

Publications

Calvo MS, Whiting SJ, Barton CN. Vitamin D fortification in the United States and Canada: current status and data needs. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1710S-6S. doi: 10.1093/ajcn/80.6.1710S. PubMed 15585792 ↗
Tangpricha V, Koutkia P, Rieke SM, Chen TC, Perez AA, Holick MF. Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health. Am J Clin Nutr. 2003 Jun;77(6):1478-83. doi: 10.1093/ajcn/77.6.1478. PubMed 12791627 ↗
Ding S, Schoenmakers I, Jones K, Koulman A, Prentice A, Volmer DA. Quantitative determination of vitamin D metabolites in plasma using UHPLC-MS/MS. Anal Bioanal Chem. 2010 Sep;398(2):779-89. doi: 10.1007/s00216-010-3993-0. Epub 2010 Jul 14. PubMed 20628873 ↗
Luque de Castro MD, Fernandez-Romero JM, Ortiz-Boyer F, Quesada JM. Determination of vitamin D3 metabolites: state-of-the-art and trends. J Pharm Biomed Anal. 1999 Jun;20(1-2):1-17. doi: 10.1016/s0731-7085(99)00027-8. PubMed 10704005 ↗
Stalmach A, Mullen W, Pecorari M, Serafini M, Crozier A. Bioavailability of C-linked dihydrochalcone and flavanone glucosides in humans following ingestion of unfermented and fermented rooibos teas. J Agric Food Chem. 2009 Aug 12;57(15):7104-11. doi: 10.1021/jf9011642. PubMed 19534535 ↗

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Feb 23, 2017, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT02422784
Lead sponsor: University of Manitoba
Collaborators: Canada Manitoba Agri-Food Research and Development Initiative
Responsible party: Sponsor
First posted: Apr 21, 2015
Start date: Jul 2016
Primary completion: Jun 2018 (estimated)
Completion: Jun 2018 (estimated)
Last update: Feb 23, 2017

Study contacts

Carla Taylor, PhD

principal investigator · University of Manitoba

Oversight

Data monitoring committee: No

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is withdrawn, as verified in Mar 2016. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Other studies in this condition

Vitamin D Deficiency→

Other studies from this sponsor

University of Manitoba

Start the discussion