Vitamin D deficiency or insufficiency Nutritional, Metabolic, Endocrine
Conditions
Interventions
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
Sponsors
Newcastle University
Eligibility
Sex/Gender
All
Age
18 Years to 100 Years
Inclusion criteria
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
Exclusion criteria
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 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
| Measure | Time frame |
|---|---|
| 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 | — |
Countries
England, United Kingdom
Contacts
Public ContactAlice Goddard
Outcome results
None listed