Repletion of vitamin D levels using an oral spray vs capsule supplement among individuals who are deficient
| ISRCTN | ISRCTN13778806 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN13778806 |
| Secondary identifying numbers | NU021205 |
- Submission date
- 15/11/2024
- Registration date
- 06/12/2024
- Last edited
- 15/04/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English summary of protocol
Background and study aims
Vitamin D is an important nutrient for bone health, helping the body to absorb calcium, magnesium, and phosphate. Vitamin D is activated in the liver and kidneys, with 25-hydroxyvitamin D (25(OH)D) being the key form used to assess vitamin D levels in the blood. The risk of vitamin D deficiency (low vitamin D levels) is higher among certain groups of individuals. For example, as people age, their bodies produce and process vitamin D differently. Older adults can often spend more time indoors, which reduces their sun exposure. This makes it harder for them to get the amount of vitamin D they need. Also, those with darker skin naturally produce less vitamin D from sunlight, especially in regions with high latitudes, such as the North East of England. Therefore, supplementation may be required to ensure these individuals have sufficient vitamin D to maintain good health. This study will compare the effectiveness of two vitamin D supplements—one in spray form and one in capsule form—among older people (study 1) and people with darker skin complexion (study 2) who have low vitamin D levels. This research aims to determine how quickly each supplement raises vitamin D levels and how well participants adhere to taking them.
Who can participate?
Otherwise healthy older adults aged 65 years and over (Study 1) and those aged 18 years and over with darker skin complexion (Study 2). Participants must either have sub-optimal (<50 nmol/l) or deficient (<30 nmol/l) vitamin D levels to be eligible and this will be determined via a screening appointment with a researcher.
What does the study involve?
If eligible, participants will be randomly allocated into one of three groups:
Group 1: Participants will be required to take a Vitamin D capsule (one capsule per day) and a placebo spray (one spray per day, orally) for 6 weeks (the placebo spray will have no active properties and is water based).
Group 2: Participants will be required to take a Vitamin D spray (one spray per day, orally) and a placebo capsule (one capsule per day) for 6 weeks (the placebo capsule will have no active properties and is water based).
Group 3: Participants will be required to take a placebo capsule (one capsule per day) and placebo spray (one spray per day, orally) for 6 weeks (the placebo capsule and spray will have no active properties and are water based).
On three occasions (at the beginning of the study, at 2 weeks and at the end of the study period at 6 weeks) participants will attend an appointment with a researcher at the Nutrition Research Facility at Newcastle University, a community-based location or online via MS Teams/Zoom. Vitamin D levels will be measured using a self-administered finger-prick blood spot kit at the baseline appointment – 0 hours (Day 1), and then at 4 and 8 hours (Day 1) followed by alternate days between Day 2 and Day 14. After Day 14, the self-administered finger prick sample will be taken weekly (days 21, 28, 35 and 42) until study completion.
What are the possible benefits and risks of participating?
To express our thanks for the participants' time and effort in taking part in the study, they will receive up to £100 shopping vouchers upon successful completion of the study. It is not intended that participation in this research study will cause any discomfort or harm. Part of this study involves providing a small blood draw via finger-prick sampling on 14 separate occasions across 6 weeks. There is a small risk of developing bruising, fainting or excessive bleeding after the blood sampling. A fully trained researcher will demonstrate how to take the blood samples safely to ensure that any discomfort or risk is minimal.
Where is the study run from?
Newcastle University (UK)
When is the study starting and how long is it expected to run for?
October 2024 to July 2025
Who is funding the study?
BetterYou Ltd (UK)
Who is the main contact?
Dr Andrea Fairley, andrea.fairley@newcastle.ac.uk
Contact information
Scientific, Principal Investigator
School of Biomedical, Nutritional and Sport Sciences
Dame Margaret Barbour Building
Newcastle Upon Tyne
NE2 4DR
United Kingdom
 ORCID ID |
0000-0003-1521-213X |
|---|---|
| Phone | +44 (0)1912080298 |
| andrea.fairley@ncl.ac.uk |
Public
School of Biomedical, Nutritional and Sport Sciences
Dame Margaret Barbour Building
Newcastle Upon Tyne
NE2 4DR
United Kingdom
| Phone | +44 (0)7350 439361 |
|---|---|
| vitdstudy@ncl.ac.uk |
Study information
| Study design | Double-blind placebo-controlled three-arm parallel-design study in two subgroups |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Community |
| Study type | Treatment |
| Participant information sheet | 46411_PIS_V2_06Nov24.pdf |
| Scientific title | Repletion rate of circulating 25-hydroxyvitamin D following sublingual and capsular vitamin D supplementation among individuals with sub-optimal vitamin D status |
| Study objectives | The hypothesis is that a 3000 IU vitamin D supplement delivered sublingually will achieve time-to-repletion rates identical to a matched enteric capsule preparation. |
| Ethics approval(s) |
Approved 05/12/2024, Newcastle University FMS Ethics Committee (Newcastle University, Newcastle Upon Tyne, NE2 4HH, United Kingdom; +44 (0)191 208 6000; fmsethics@newcastle.ac.uk), ref: 2922/50103 |
| Health condition(s) or problem(s) studied | Vitamin D deficiency or insufficiency |
| Intervention | This study will involve two, double-blind, placebo-controlled trials (6-week duration), each with a three-arm parallel design. Study 1 will target older adults (65 years and above) (n = 75); Study 2 will target adults with darker skin complexion (18 years and above) (n = 75). Each study will follow the same design and will be operationalised concurrently. Participants will be randomised into one of three groups: Study 1: Older adults 1. Active vitamin D capsule (3000 IU, 1 x capsule/day) and 1 x placebo spray (1 x spray orally/day) for 6 weeks (n = 25) 2. Active vitamin D spray (3000 IU, 1 x spray orally/day) and placebo capsule (1 x capsule/day) for 6 weeks (n = 25) 3. Double placebo (1 x spray orally/day & 1 x capsule/day) for 6 weeks (n = 25) Study 2: Adults with darker skin complexion 1. Active vitamin D capsule (3000 IU, 1 x capsule/day) and 1 x placebo spray (1 x spray orally/day) for 6 weeks (n = 25) 2. Active vitamin D spray (3000 IU, 1x spray orally/day) and placebo capsule (1 x capsule/day) for 6 weeks (n = 25) 3. Double placebo (1 x spray orally/day & 1 x capsule/day) for 6 weeks (n = 25) A double-blinded method will be applied for both subjects and investigators. The identity of the groups will be disclosed upon completion of the data analysis. |
| Intervention type | Supplement |
| Primary outcome measure | Time from initiation of supplementation to participants meeting the definition of adequate circulating levels of vitamin D [25(OH)D] analysed by liquid chromatography tandem mass spectrometry measured by a self-administered finger prick blood spot at baseline – 0 h (day 1), and then at 4 h and 8 h (day 1), day 2, 4, 6, 8, 10, 12, 14, 21, 28, 35 and 42. |
| Secondary outcome measures | 1. Compliance measured by weighing/counting the spray bottle and capsules at 2 weeks and 6 weeks. 2. Acceptability measured using a questionnaire at 6 weeks |
| Overall study start date | 06/10/2024 |
| Completion date | 31/07/2025 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 150 |
| Key inclusion criteria | 1. Older adults aged 65 years and over (Study 1) 2. Adults aged 18 years and over with darker skin complexion. This is classified using the Fitzpatrick Classification of Skin Phototype (Phototype IV, V, VI) (Fitzpatrick, 1988) (Study 2) 3. Participants to be screened for sub-optimal 25(OH)D status (<50 nmol/L) or deficient (<30 nmol/L) 25(OH)D status at baseline (both Study 1 and 2) 4. Willing and able to give written informed consent 5. Can understand and speak the English language |
| Key exclusion criteria | 1. Individuals who report any food supplement use 2. Individuals with a Vitamin D status of ≥50 nmol/L 3. Recent or planned overseas vacation / sunny holiday 4. Pregnant or lactating women 5. History of gastrointestinal disease, liver disease, or renal disease 6. History of bleeding disorders, and/or taking blood thinning medications 7. Skin disorders that would impede finger prick sampling 8. Those living with diabetes 9. Any disability or mental impairment that precludes safe and adequate participation in the study and inability to provide consent 10. Inability to understand written and verbal instructions in English |
| Date of first enrolment | 11/12/2024 |
| Date of final enrolment | 20/06/2025 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Newcastle upon Tyne
NE1 7RU
United Kingdom
Sponsor information
University/education
School of Biomedical, Nutritional and Sport Sciences
Dame Margaret Barbour Building
Newcastle Upon Tyne
NE2 4DR
England
United Kingdom
| Phone | +44 (0)1912080298 |
|---|---|
| fms.postawardfinance@newcastle.ac.uk | |
| Website | https://www.ncl.ac.uk/ |
"ROR" |
https://ror.org/01kj2bm70 |
Funders
Funder type
Industry
No information available
Results and Publications
| Intention to publish date | 31/10/2025 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| Publication and dissemination plan | Data arising from the study will be considered for dissemination at scientific conferences with a plan for publication in a high-impact peer-reviewed journal. |
| IPD sharing plan | The data-sharing plans for the current study are unknown and will be made available at a later date |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | version 2 | 06/11/2024 | 06/12/2024 | No | Yes |
| Participant information sheet | version 3 | 06/03/2025 | 10/03/2025 | No | Yes |
Additional files
Editorial Notes
15/04/2025: The following changes were made:
1. The recruitment end date was changed from 20/04/2025 to 20/06/2025.
2. The overall study end date was changed from 31/05/2025 to 31/07/2025.
10/03/2025: The following changes were made to the study record:
1. The recruitment end date was changed from 28/02/2025 to 20/04/2025.
2. The overall study end date was changed from 01/05/2025 to 31/05/2025.
3. Participant information sheet uploaded.
06/12/2024: Study's existence confirmed by the Newcastle University FMS Ethics Committee.
