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Comparison of Sunlight Exposure and Vitamin D Supplementation on Serum 25-hydroxyvitamin D Levels

Not Applicable
Completed
Conditions
Vitamin D Deficiency
Cardiometabolic Risk Factors
Interventions
Behavioral: Sunlight Exposure
Dietary Supplement: Vitamin D Supplementation
Other: Placebo
Registration Number
NCT03310242
Lead Sponsor
Seoul National University Hospital
Brief Summary

This study aimed to compare the effects between sunlight exposure and oral vitamin D supplementation on serum 25-hydroxyvitamin D concentration and metabolic markers in Korean young adults.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
150
Inclusion Criteria
  • Serum 25(OH)vitamin D < 12ng/mL
  • age between 18 and 39 years
  • Korean men and women
Exclusion Criteria
  • Vitamin D supplementation within 2 months
  • Photosensitivity or UV allergy
  • History of hyperparathyroidism/hypercalciuria/kidney stone/skin cancer and other cancer
  • Under medication for hypertension, dyslipidemia, and diabetes
  • Intake of photosensitive medicine during study period
  • Exposure of strong UV (e.g., beach, sun tanning) during study period
  • Pregnant/breast-feeding women

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Sunlight ExposureSunlight ExposureEveryday sunlight exposure around noon for 20-30 minutes for 8 weeks
Vitamin D SupplementationVitamin D SupplementationSupplementation of vitamin D3 500 IU/day for 8 weeks
PlaceboPlaceboIntake of placebo for 8 weeks
Primary Outcome Measures
NameTimeMethod
Serum 25(OH)DBaseline, 4 week, and 8 week

Changes in serum 25(OH)D levels in ng/mL

Secondary Outcome Measures
NameTimeMethod
Diastolic blood pressureBaseline, 4 week, and 8 week

Diastolic blood pressure changes in mmHg

Lipid panelBaseline and 8 week

Serum total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol in mg/dL

Fasting glucoseBaseline and 8 week

Serum fasting glucose in mg/dL

BMIBaseline, 4 week, and 8 week

Weight and height will be combined to report BMI in kg/m\^2

Systolic blood pressureBaseline, 4 week, and 8 week

Systolic blood pressure changes in mmHg

ASTBaseline and 8 week

Serum AST levels in mg/dL

ALTBaseline and 8 week

Serum ALT levels in mg/dL

GGTBaseline and 8 week

Serum AST, ALT, and GGT levels in mg/dL

Intact PTHBaseline and 8 week

Serum intact PTH levels in mg/dL

Whole body BMD and BMCBaseline and 8 week

Whole body BMD (g/cm\^2) and BMC (kg) measured by DEXA

Lean body mass, fat mass, and percent fatBaseline and 8 week

Lean body mass (kg), fat mass (kg), and percent fat (%) measured by DEXA

Lean body mass, muscle mass, skeletal muscle mass, fat mass, and percent fatBaseline, 4 week, and 8 week

Lean body mass (kg), muscle mass (kg), skeletal muscle mass (kg), fat mass (kg), and percent fat (%) measured by body impedance analysis

EQ-5D-5LBaseline, 4 week, and 8 week

Quality of life measured using EQ-5D-5L scale. The EQ-5D is a standardised measure of health status developed by the EuroQol Group in order to provide a simple, generic measure of health status. In description part, health status is measured in terms of five dimensions (5D); mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The respondents self-rate their level of severity for each dimension using three-level (EQ-5D-3L) or five-level (EQ-5D-5L) scale. The 5-level version of EQ-5D (EQ-5D-5L) was developed to improve such constraints of the three-level scale.

EQ-5D-5L scale can define 3,125 (=5\^5) different health states, and the 5-digit number can be converted into a preference weight which is also referred to as a single weighted index score. The index score of a value set derived from the general population sample can be regarded as a "societal valuation of the respondent's health state" in that country.

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