Clinical trial NCT05802433: The Genetic Effects on Vitamin D Supplementation
Official title: Effects of VDR rs7311856, GC rs2282679 and CYP2R1 rs2060793 Variants on Vitamin D Status: A Randomised Control Trial
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Vitamin D Deficiency
Lead sponsor: St. Mary's University, Twickenham
Sponsor class: OTHER
First posted: 2023-04-06
Enrollment: 67
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants are grouped based on their genetic risk of vitamin D deficiency, all participants are given 10µg vitamin D supplements for 90 days
Primary purpose: BASIC_SCIENCE

Brief summary: Vitamin D is essential for skeletal growth and bone health, deficiency causes rickets and osteomalacia. In the UK 29% of adults have vitamin D deficiency. It is recommended all adults take 10µg vitamin D supplement daily. Genetic variations could alter vitamin D status by affecting vitamin D metabolism. Systematic reviews found variations in VDR, GC and CYP2R1 genes are associated with vitamin D deficiency. This study aims to assess the effects between vitamin D supplementation and variations in VDR, GC and CYP2R1 genes on vitamin D status.

Detailed description: The study design is a quantitative, randomised control trial measuring vitamin D concentrations in blood serum. All participants will be given the recommended 10µg daily dose of vitamin D supplementation. Participants will be grouped based on their genotype for each gene, as either low, medium or high-risk genotypes. The low-risk group will act as a control and the medium and high-risk groups will act as the intervention groups.

Participants will attend St Mary's University's applied science laboratory twice. During their first visit participants will provide a 2ml capillary blood sample. Blood samples are collected using lancets to prick participants' ear lobes. The serum is extracted from the blood samples, serum is stored at -80c until analysis. Participants will be given 90 10µg vitamin D supplements and instructed to take one per day for 90 days. Participants will also be instructed to not make any major changes to their habitual diet. During the second visit participants will provide 1 ml of saliva sample into the Collection Pot and a second 2ml sample of blood. Serum samples will be analysed for vitamin D concentrations using 25(OH) Vitamin D ELISA kit. DNA will be extracted from the saliva samples using PSP SalivaGene DNA Kit following the manufacturer's protocol. DNA will be genotyped for variations in the VDR, GC and CYP2R1 genes. Data will be assessed to determine if variations in these genes influenced the effectiveness of vitamin D supplementation.

Eligibility criteria: Inclusion Criteria:

* Healthy adults
* female and male
* 18-65 years
* completion of physical activity readiness questionnaire (PAR-Q).

Exclusion Criteria:

* Below 18 years
* above 65 years
* individuals taking medications that could interact with vitamin D status
* Individuals regularly taking daily Vitamin D supplementation during the 3 months before the intervention start date
* major dietary changes in vitamin D intake during the intervention period

Primary outcomes:
measure: vitamin D concentration
timeFrame: 90 days
Secondary outcomes:
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: St Mary's University Twickenham
state: Lobdon
Study officials:
affiliation: St. Mary's University, Twickenham
name: Yiannis Mavrommatis
role: PRINCIPAL_INVESTIGATOR
References:
citation: Krasniqi E, Boshnjaku A, Wagner KH, Wessner B. Association between Polymorphisms in Vitamin D Pathway-Related Genes, Vitamin D Status, Muscle Mass and Function: A Systematic Review. Nutrients. 2021 Sep 4;13(9):3109. doi: 10.3390/nu13093109.
citation: National Health Service (NHS) (2020) Vitamin D. Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
citation: National Institute for Health and Care Excellence (NICE) (2017) Vitamin D: supplement use in specific population groups. Available at: https://www.nice.org.uk/guidance/ph56/
citation: Public Health England (PHE) (2019) National Diet and Nutrition Survey: Years 1 to 9 of the Rolling Programme (2008/2009 - 2016/2017): Time trend and income analyses. Available at: https://assets.publishing.service.gov.uk/
citation: Sepulveda-Villegas M, Elizondo-Montemayor L, Trevino V. Identification and analysis of 35 genes associated with vitamin D deficiency: A systematic review to identify genetic variants. J Steroid Biochem Mol Biol. 2020 Feb;196:105516. doi: 10.1016/j.jsbmb.2019.105516. Epub 2019 Oct 31.