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| Name | Class |
|---|---|
| University of Reading | OTHER |
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The aim of this study is to perform a double-blind, randomised, dose-response trial of vitamin D3 supplementation in United Kingdom (UK)-dwelling adults of white European, South Asian, and black African/Caribbean ethnicity to investigate the distribution of dietary intakes needed to maintain adequate vitamin D status in winter, as indicated by serum 25(OH)D concentrations at ranges of >25 to 50 nmol/L. In addition, this study will investigate the effect of vitamin D3 supplementation on immune health, muscular strength, and overall health.
The aim of this study is to perform a double-blind, randomised, dose-response trial of vitamin D3 supplementation in United Kingdom (UK)-dwelling adults of white European, South Asian, and black African/Caribbean ethnicity to investigate the distribution of dietary intakes needed to maintain adequate vitamin D status in winter, as indicated by serum 25(OH)D concentrations at ranges of >25 to 50 nmol/L. In addition, this study will investigate the effect of vitamin D3 supplementation on immune health, muscular strength, and overall health. Recruited participants will be randomised to take 400, 1000, or 2000 IU for 12 weeks. Fasting blood samples collected at baseline and 12 weeks will measure biochemical markers of vitamin D status (serum 25(OH)D, calcium, parathyroid hormone, albumin), lipid profile, ferritin, micronutrient status, and immune and inflammatory biomarkers. Muscular strength will be measured using sit-to-stand and grip strength tests. Questionnaires, food diaries, and dosimeters will be used to gather data on lifestyle, physical activity, dietary intake, and sun exposure.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Vitamin D Supplement 400 IU | Active Comparator | 400 IU (10 µg) of Vitamin D3 |
|
| Vitamin D Supplement 1000 IU | Active Comparator | 1000 IU (25 µg) of Vitamin D3 |
|
| Vitamin D Supplement 2000 IU | Active Comparator | 2000 IU (50 µg) of Vitamin D3 |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Vitamin D Supplement | Dietary Supplement | Vitamin D Supplement |
|
| Measure | Description | Time Frame |
|---|---|---|
| Concentration of serum 25(OH)D (nmol/L) | A blood sample will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS). Dose-response change in serum 25(OH)D will be measured in nmol/L. | Baseline and 12 weeks |
| Measure | Description | Time Frame |
|---|---|---|
| Anthropometric measurements - weight (kg) | Weight (kg) | Baseline and 12 weeks |
| Anthropometric measurements - height (m) | Height (m) | Baseline and 12 weeks |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Role | Phone | Extension | |
|---|---|---|---|---|
| Abigail Bournot, PhD | Contact | 01483689222 | a.bournot@surrey.ac.uk | |
| Susan Lanham-New | Contact | 01483686476 | s.lanham-new@surrey.ac.uk |
| Name | Affiliation | Role |
|---|---|---|
| Abigail Bournot | University of Surrey | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Faculty of Health and Medical Sciences | Recruiting | Guildford | GU2 7XH | United Kingdom |
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| ID | Term |
|---|---|
| D014808 | Vitamin D Deficiency |
| ID | Term |
|---|---|
| D001361 | Avitaminosis |
| D003677 | Deficiency Diseases |
| D044342 | Malnutrition |
| D009748 | Nutrition Disorders |
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Recruited participants will be randomised to take 400,1000, or 2000 IU for 12 weeks.
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| Anthropometric measurements - height (cm) | Height (cm) | Baseline and 12 weeks |
| Anthropometric measurements - waist circumference (cm) | Waist circumference measurement (cm) | Baseline and 12 weeks |
| Anthropometric measurements - hip circumference (cm) | Hip circumference measurement (cm) | Baseline and 12 weeks |
| Concentration of serum calcium (nmol/L) | Measure dose-response change in serum calcium measured in nmol/L | Baseline and 12 weeks |
| Concentration of plasma parathyroid hormone (PTH) (pg/mL) | Measure dose-response change in plasma parathyroid hormone (PTH) measured in pg/mL | Baseline and 12 weeks |
| Concentration of serum albumin (g/L) | Measure dose-response change in serum albumin measured in g/L | Baseline and 12 weeks |
| Concentration of C-Reactive Protein (CRP) (mg/L) | Measure dose-response change in CRP measured in mg/L | Baseline and 12 weeks |
| Complete blood count | Measure change in complete blood count | Baseline and 12 weeks |
| Change in immune parameters | Measure change in gene expression in white blood cells | Baseline and 12 weeks |
| Number of participants with Acute Respiratory Tract Infections (ARTIs) | Measure the frequency of ARTIs using a validated questionnaire | 12 weeks |
| Muscular strength using a handgrip strength test (kg) | Muscular strength measured using a dynamometer (measured to the nearest 0.1kg). The participant will squeeze the dynamometer with maximum effort for 5 seconds. | Baseline and 12 weeks |
| Muscular strength and endurance using a sit-to-stand test | Number of sit to stands in 30 seconds | Baseline and 12 weeks |
| Blood analytes - micronutrient status | Measure dose-response change in micronutrient status from blood samples | Baseline and 12 weeks |
| Blood analytes - lipid profile (mg/dL) | Measure change in lipid profile from blood samples measured in mg/dL | Baseline and 12 weeks |
| Vitamin D consumption from diet | Vitamin D intake will be measured through a 4-day food diary which participants will fill out for 4 day at home before and after the study. | Baseline and 12 weeks |
| Physical activity questionnaire | Assess level of physical activity using an International Physical Activity Questionnaire (short form) | Baseline |
| Sun exposure behaviour questionnaire | Measures amount of time spent in the sun (often, occasionally, never) and what parts of the body are exposed (head, hands, arms, legs, torso) over summer, spring, autumn and winter. Also questions any summer holidays abroad, in what month, what country was visited, number of hours of sun per day and what body parts were exposed (head, hands, arms, legs, torso) | Baseline |
| Ultraviolet B radiation (UVB) sun exposure | Sun exposure will be measured by a dosimeter, which measures UVB exposure. Participants wear this like a badge for 4 days before and after the study. | Baseline and 12 weeks |
| Lifestyle questionnaire | Measures: - Skin type (Fitzpatrick scale) Questions: Questions what ethnicity they identify with, Holidays abroad, Education, Origin, Health, Pregnancy, Sun behaviours (what body parts are usually exposed to the sun, clothing, sun bathing, sunscreen use, sun bed use), Smoking, Drinking, Recreational drug use, Knowledge around vitamin D, supplement use, Milk, egg, oily fish and liver consumption | Baseline |
| D009750 |
| Nutritional and Metabolic Diseases |