Vitamin D and Immunity: Photosynthesis Versus Supplementation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 36
- 主要终点
- Vitamin D status of healthy participants treated with oral vitamin D (cholecalciferol) or UVR (SSR) exposures and control (untreated)
研究概览
简要总结
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
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age: 18-40
- •Fitzpatrick skin type I/II
- •Serum 25(OH)D3 <50nmol/L
排除标准
- •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
研究组 & 干预措施
Control
No intervention
UVR (Solar simulated radiation)
Twice weekly 1.25 SED (sub-erythemal) (4 weeks)
干预措施: UVR (Solar simulated radiation) (Radiation)
Vitamin D3 supplementation
4X 1000IU cholecalciferol tablets daily (28 days)
干预措施: Vitamin D (Dietary Supplement)
结局指标
主要结局
Vitamin D status of healthy participants treated with oral vitamin D (cholecalciferol) or UVR (SSR) exposures and control (untreated)
时间窗: 3 years
Measure 25(OH)D3nmol/L via LC-MS/MS
次要结局
- Gene expression in peripheral blood myeloid and plasmacytoid dendritic cells(3 years)
- Impact upon the frequency and phenotype of peripheral blood dendritic cells(3 years)
- Changes to peripheral blood cell frequency(3 years)