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Completed

NCT Number: NCT03609970

Vitamin D and Immunity: Photosynthesis Versus Supplementation

The optimal way to restore serum 25-hydroxyvitamin D sufficiency is currently debatable. UV irradiation through sunshine exposure promotes endogenous vitamin D synthesis, although this can also be associated with a risk of UVR-induced skin cancer. Dietary supplements represent an alternative, which are increasingly being used in clinical trials to correct deficiency. However, it is unclear whether sunshine exposure and vitamin D supplementation induce comparable changes in immune function, or whether additional UVR-induced molecules may be responsible for proposed health benefits. Several studies report an inverse correlation between exposure to UVR and immune-mediated diseases, further supporting the theory that UVR may also be protective through non vitamin-D mediated pathways. So far it has been difficult to distinguish between immune-regulation by vitamin D and other mediators induced by UVR as the downstream effects are similar. A direct comparison of the biological effects of vitamin D obtained by UVR versus supplementation has never been made. This study aims to elucidate the differences in vitamin D generated by UVR exposure versus supplementation by comparing immunological endpoints

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Key information

Conditions

Vitamin D Deficiency Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Nutritional and Metabolic Diseases

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age: 18-40
  • Fitzpatrick skin type I/II
  • Healthy
  • Serum 25(OH)D3 <50nmol/L

Exclusion criteria

Serum 25(OH)D3 >50nmol/L

  • Pregnant or nursing women
  • Women of child bearing age not using adequate contraception
  • Are taking photosensitizing medication (i.e. causes you to be more sensitive to sunlight)
  • Have had a history of skin disorders, sensitive skin, sensitivity to sunlight or skin cancer
  • Have previously had an organ transplant
  • Have partaken in a clinical study within the last 14 days
  • Have had recent exposure to sunbeds (last 4 months) or holiday sun (including skiing)
  • Are currently or have taken vitamin D supplements in the last 4 months Are asthmatic or suffer from any allergies

Treatment and study plan

Vitamin D

Dietary Supplement

Daily 4X 1000IU cholecalciferol

UVR (Solar simulated radiation)

Radiation

1.25 SED Solar simulated radiation twice weekly

Primary outcomes

  1. Vitamin D status of healthy participants treated with oral vitamin D (cholecalciferol) or UVR (SSR) exposures and control (untreated)

    Time frame: 3 years

    Measure 25(OH)D3nmol/L via LC-MS/MS

Secondary outcomes

  1. Changes to peripheral blood cell frequency

    Time frame: 3 years

    Frequency of major peripheral immune cells (e.g. CD3+ T cells, CD3+ CD4+ T cells, CD3+ CD8+ T cells, CD19+ B cells, Natural Killer Cells, Classical, Non-classical and Intermediate Monocytes) in participants when vitamin D insufficient and sufficient. Via flow cytometry.

  2. Impact upon the frequency and phenotype of peripheral blood dendritic cells

    Time frame: 3 years

    Frequency of peripheral blood dendritic cells (myeloid and plasmacytoid) in individuals with insufficient vitamin D levels and following vitamin D repletion via supplementation or UVR (SSR) exposures. Assessment of markers of maturation/tolerogenicity (MFI and frequency expressing) on myeloid and plasmacytoid dendritic cells direct ex vivo and after stimulation in vitro in participants when vitamin D insufficient and sufficient.

  3. Gene expression in peripheral blood myeloid and plasmacytoid dendritic cells

    Time frame: 3 years

    Differentially regulated genes in myeloid and plasmacytoid dendritic cells in participants after vitamin D repletion via supplementation and UVR (SSR) exposure via Microarray.

Sponsors and collaborators

Lead sponsor

Guy's and St Thomas' NHS Foundation Trust

Other

Registry information

Acronym: IMMUNI-D

Important dates

Study start
2015
Primary completion
2017
Study completion
2017
First posted
Aug 1, 2018
Registry last updated
Aug 1, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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