Effect of Vitamin D on Cardiovascular Metabolic Risk in Overweight/Obesity Adolescents in China

The Improvement Effect of Vitamin D on the Cardiovascular Health of Overweight/Obesity Adolescents in China

The goal of this randomized controlled clinical trial is to investigate the effects of vitamin D3 supplementation on cardiometabolic risk in Chinese adolescents with overweight/obesity and vitamin D deficiency. The main question it aims to answer whether vitamin D3 supplementation can improve cardiovascular metabolic health.

Participants in the intervention group will receive vitamin D3. The control group will receive vitamin D placebo.

Researchers will compare the change in cardiometabolic risk from baseline to post-intervention at 12 weeks between the intervention and control groups.

Investigators will conduct a randomized controlled trial to examine whether vitamin D3 supplementation can improve cardiovascular metabolic health. A total of 130 participants will be recruited from two middle schools. Inclusion criteria were students with both students and parents signing a paper version of the informed consent form, overweight/obesity and serum 25(OH)D concentration of 12~20ng/ml. Exclusion criteria are any disease that affects vitamin D metabolism (e.g., functional/organic brain disease, severe infectious disease, chronic gastrointestinal disease, hepatic or renal insufficiency, etc.); known chronic disease (e.g., cardiovascular disease); use of vitamin D supplements in the past 3 months; and adolescents with allergies to vitamin D or soybean oil ingredients. Participants will be randomly assigned into a supplementation or placebo group. Supplementation arm will receive oral dose 2000 IU vitamin D3 per day for 6 weeks and followed by 800 IU per day for 6 weeks, placebo arm will receive placebo every day for 12 weeks. For the first 6 weeks, vitamin D or placebo will be administrated every two weeks. For the next 6 weeks, vitamin D or placebo will be administrated every 3 weeks. The primary outcome of this study is to compare the change of cardiometabolic risk between supplementation or placebo group from post-intervention 12 weeks.

Inclusion Criteria:

1. Students whose caregivers signed informed consents;
2. Students with serum 25(OH)D concentration of 12-20 ng/mL;
3. Students with overweight or obesity.

Exclusion Criteria:

1. Students with any disease that affects vitamin D metabolism (e.g., functional/organic brain disease, severe infectious disease, chronic gastrointestinal disease, hepatic or renal insufficiency, etc.);
2. Students with known chronic disease (e.g., cardiovascular disease); use of vitamin D supplements in the past 3 months;
3. Students with allergies to vitamin D or soybean oil ingredients.