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Assessment of Vitamin D Supplementation and Immune Function

Not Applicable
Completed
Conditions
Vitamin D Deficiency
Interventions
Dietary Supplement: Vitamin D - Treatment 1
Dietary Supplement: Vitamin D - Treatment 2
Dietary Supplement: Vitamin D - Treatment 3
Registration Number
NCT01399151
Lead Sponsor
USDA, Western Human Nutrition Research Center
Brief Summary

Hypothesis:

Volunteers with vitamin D insufficiency (serum 25(OH)D 25-50 nmol/L) given intermediate or high dose vitamin D supplements (2,000 or 5,000 IU per day) will have increased production of anti-bacterial peptides and interleukin-1, decreased production of other pro-inflammatory cytokines, increased production of regulatory cytokines and an enhanced T- and B-cell response to a tetanus vaccine compared to vitamin D insufficient subjects given low dose vitamin D supplements (400 IU per day).

Detailed Description

Specific Aim 1:

Determine if high dose vitamin D supplements decrease the production of proinflammatory and increase the production of regulatory cytokines and chemokines by innate immune cells stimulated ex vivo.

Specific Aim 2:

Determine if high dose vitamin D supplements decrease serum markers of inflammation and increase serum and cellular levels of defensive molecules (e.g., cathelicidin).

Specific Aim 3:

Determine if high dose vitamin D supplements decrease blood levels of proinflammatory T-helper type 1 (Th1) and Th17 cells and increase levels of anti-inflammatory T-regulatory (Treg) and Th2 cells.

Specific Aim 4:

Determine if high dose vitamin D supplements increase antigen specific T cell and B cell responses after tetanus vaccination.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
23
Inclusion Criteria
  • Age 20-49 (men) and 20-45 (women)
  • BMI 18.5-30
  • Serum 25OH Vitamin D 25-50 nmol/L
Exclusion Criteria
  • Pregnant or nursing women
  • Daily smoker
  • Anemia (Hgb<12 mg/dL for women and <13 mg/dL for men) determined at initial visit
  • Any report or diagnosis of disease or chronic condition that may affect vitamin D absorption such as cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease
  • Diagnosis of hyper parathyroidism and chronic granulomatous disease, which increases risk of hypercalcemia.
  • Planned to travel to a location at which either altitude or latitude would result in significant vitamin D synthesis during the study period.
  • Not previously vaccinated with TT, or vaccinated within five years
  • Use of steroids or antibiotics within the past 4 weeks
  • Current use of nutritional supplements that may alter immune function such as omega 3 fatty acid supplements
  • Current use of anti-inflammatory or anti-convulsion medications
  • Self reported history of significant adverse response to previous vaccinations

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Vitamin D - Treatment 1Vitamin D - Treatment 1400 IU/day Vitamin D
Vitamin D- Treatment 2Vitamin D - Treatment 22,000 IU/day Vitamin D
Vitamin D- Treatment 3Vitamin D - Treatment 35,000 IU/day Vitamin D
Primary Outcome Measures
NameTimeMethod
Change in cytokine levels from stimulated Periferal Blood Mononuclear Cells0, 8 and 12 weeks
Change in Cathelicidin levels in granulocytes0, 8, and 12 weeks
Change in serum cytokines and acute phase proteins0, 8 and 12 weeks
Change in serum 25OH Vitamin D0, 4, 8, and 12 weeks
Change in markers of response to tetanus vaccination0, 8, 9, 10 and 12 weeks

Markers of response to tetanus vaccine include tetanus-specific proliferation and production of cytokines by CD4 T-helper cells.

Change in urinary calcium-to-creatinine ratio0, 2, 4, 6, 8 and 10 weeks
Secondary Outcome Measures
NameTimeMethod
Change in level of 5-lipoxygenase protein in granulocytes0, 8 and 12 weeks
Change in production of leukotrienes in granulocytes0, 8, and 12 weeks

Trial Locations

Locations (1)

Western Human Nutrition Center, University of California Davis

🇺🇸

Davis, California, United States

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