Lecture 9 Cancer Prevention or Exacerbation – Folate and Vitamin D
Evidence based medicine aims to:
•Apply best available evidence from clinical trials to clinical decision making
•Assess strength of evidence with respect to risk/benefits of treatment/diagnostic
tests
Levels of evidence
I: RCTs, meta-analyses, systematic reviews
II: Cohort, case control studies
III: opinions, case studies, expert communities
Phases of clinical trials
Phase 1: Safety Screening
Phase 2: Dose-finding, initial efficacy
Phase 3: Final testing: efficacy and compare to current Rx
Phase 4: “post-approval” studies
Clinical evidence against smoking based on prospective cohort epidemiology
Low 25(OH)D predicts multiple sclerosis (MS)
1,25(OH)2D affects antigen presentation & Th1 development
1,25(OH)2D influences Th1/Th2 development
Linking vitamin D with MS
•Geographical variation
•Immunomodulation of 1,25(OH)2D
•Season of birth
•VDDR1 and concurrent MS case study
•Relapse/remission and increase/decrease 25(OH)D
•Oral vitamin D intake, UVB radiation
•Decreased 25(OH)D
•Seasonal MRI activity
A phase 1/2 dose escalation study of high dose of vitamin D supplementation in MS
patients (randomized, open-label, matched intervention trial)
Summary:
•Mean serum 25(OH)D concentration ~420nmol/L without significant changes in
serum/urinary Ca measures
•Dosing regimen physiologically attainable 25(OH)D concentrations at 1yr
•No significant adverse effects
•Treatment group improve
Lymphocyte proliferation assay
•T cell proliferative response to MS-associated antigentic stimulation were
significantly reduced in treated