Cardiometabolic Risk Factors, Vitamin D Deficiency
Conditions
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.
Interventions
BEHAVIORALSunlight Exposure
* Everyday sunlight exposure around noon for 20-30 minutes for 8 weeks * Completing a Sun Diary after sunlight exposure
DIETARY_SUPPLEMENTVitamin D Supplementation
\- Supplementation of vitamin D3 500 IU/day for 8 weeks
OTHERPlacebo
\- Intake of placebo for 8 weeks
Sponsors
Seoul National University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 39 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Serum 25(OH)D | Baseline, 4 week, and 8 week | Changes in serum 25(OH)D levels in ng/mL |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Systolic blood pressure | Baseline, 4 week, and 8 week | Systolic blood pressure changes in mmHg |
| Diastolic blood pressure | Baseline, 4 week, and 8 week | Diastolic blood pressure changes in mmHg |
| Lipid panel | Baseline and 8 week | Serum total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol in mg/dL |
| Fasting glucose | Baseline and 8 week | Serum fasting glucose in mg/dL |
| AST | Baseline and 8 week | Serum AST levels in mg/dL |
| ALT | Baseline and 8 week | Serum ALT levels in mg/dL |
| BMI | Baseline, 4 week, and 8 week | Weight and height will be combined to report BMI in kg/m\^2 |
| Intact PTH | Baseline and 8 week | Serum intact PTH levels in mg/dL |
| Whole body BMD and BMC | Baseline and 8 week | Whole body BMD (g/cm\^2) and BMC (kg) measured by DEXA |
| Lean body mass, fat mass, and percent fat | Baseline 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 fat | Baseline, 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-5L | Baseline, 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. |
| GGT | Baseline and 8 week | Serum AST, ALT, and GGT levels in mg/dL |
Outcome results
None listed