Estimation of the Dietary Requirement for Vitamin D in Ethnic Groups

Estimation of the Dietary Requirement for Vitamin D in Ethnic Groups: a Double-blind, Randomised, Dose-response Trial

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.

Study Overview

• Status: Recruiting
• Conditions: Vitamin D Deficiency; Immune Health; Muscle Function
• Intervention / Treatment: Dietary supplement: Vitamin D Supplement

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 114
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Susan Lanham-New; Phone Number: 01483686476; Email: s.lanham-new@surrey.ac.uk
• Study Contact Backup: Name: Abigail Bournot, PhD; Phone Number: 01483689222; Email: a.bournot@surrey.ac.uk

Study Locations

• United Kingdom
  • Guildford, United Kingdom, GU2 7XH
    • Recruiting
    • Faculty of Health and Medical Sciences
    • Contact: Susan Lanham-New; Phone Number: 01483686476; Email: s.lanham-new@surrey.ac.uk
    • Contact: Abigail Bournot, PhD; Phone Number: 01483689222; Email: a.bournot@surrey.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• British white European, black African/Caribbean, or South Asian (self-reported)
• Living in England for >2 months
• Aged >18 years
• No significant health issues
• English or Urdu speaker

Exclusion Criteria:

• Medical condition or history which might impact study measurements (e.g., ischaemic heart disease, type 1 and type 2 diabetes, thyroid disease, osteoporosis, haematological disease, malignancy)
• Medications known to affect vitamin D metabolism (i.e., hormone replacement therapy, anti-oestrogens treatment, antiepileptic drugs, and breast cancer treatment)
• Pregnant or planning pregnancy during the study period
• Regular use of sun beds
• Having a sun holiday one month prior to commencing study or plans for a sun holiday within the study period. A sun holiday is generally defined as a holiday in a sunny resort outside of the UK. The researchers will assess this on a case-by-case basis depending on the time of year and expected weather conditions
• Reported participation in another clinical trial occurring simultaneously
• Previous intolerance or allergic reaction to vitamin D

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Vitamin D Supplement 400 IU; 400 IU (10 µg) of Vitamin D3	Dietary supplement: Vitamin D Supplement; Vitamin D Supplement
Active Comparator: Vitamin D Supplement 1000 IU; 1000 IU (25 µg) of Vitamin D3	Dietary supplement: Vitamin D Supplement; Vitamin D Supplement
Active Comparator: Vitamin D Supplement 2000 IU; 2000 IU (50 µg) of Vitamin D3	Dietary supplement: Vitamin D Supplement; Vitamin D Supplement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anthropometric measurements - weight (kg)	Weight (kg)	Baseline and 12 weeks
Anthropometric measurements - height (m)	Height (m)	Baseline and 12 weeks
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 peripheral blood mononuclear cell (PBMC) profile	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
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

Collaborators and Investigators

• Sponsor: University of Surrey
• Collaborators: University of Reading
• Investigators: Principal Investigator: Abigail Bournot, University of Surrey

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2023
• Primary Completion (Estimated): September 1, 2025
• Study Completion (Estimated): September 1, 2025

Study Registration Dates

• First Submitted: September 20, 2023
• First Submitted That Met QC Criteria: September 27, 2023
• First Posted (Actual): October 5, 2023

Study Record Updates

• Last Update Posted (Actual): October 5, 2023
• Last Update Submitted That Met QC Criteria: September 27, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Vitamin D
• Other Study ID Numbers: FHMS 22-23 194 EGA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No