The Effect of Vitamin D Repletion on Small Low Density Lipoprotein (LDL) Particle Number in Subjects at Elevated Cardiovascular Risk

Study Overview
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Brief Summary
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Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced in the body when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D is essential for promoting calcium absorption and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and bone growth. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis. Many people have low levels of Vitamin D. Replacing Vitamin D is thought to help lower the risk of heart disease. Vitamin D may be helpful, but it could also be harmful. The investigators are studying the effect of Vitamin D on the level of a harmful kind of cholesterol. Participants will have their cholesterol levels measured and then receive either Vitamin D or a placebo. After 2 months of treatment, the investigators will measure their cholesterol levels again.

Official Title
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The Effect of Vitamin D Repletion on Small LDL Particle Number in Subjects at Elevated Cardiovascular Risk

Conditions
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Atherosclerosis

Intervention / Treatment
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* Dietary Supplement: Vitamin D3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 years and < 85 years Vitamin D 25-OH level <20 ng/ml One of the following risk factors: Known coronary artery disease (CAD) or a CAD equivalent (e.g. diabetes, chronic kidney disease, etc) BMI > 30 kg/m2 Random Glucose Level > 200mg/dl Increased Waist Circumference (male: > 40in; Females: > 35in.) Decreased HDL (Male: < 40mg/dl; Female: < 50mf/dl) Framingham Risk Score > 10% hsCRP > 2 mg/L Exclusion Criteria: Serum phosphorus level > 5.5 mg/dl Estimated GFR <30 ml/min/1.73m2 Use of Vitamin D >400 IU/day within 1 month of most recent Vitamin D 25-OH determination Use of calcitriol or other activated vitamin D Change in statin, ezetimibe, niacin, fibrate dose within 1 month Concurrent participation in an investigational drug study Have any other condition, which in the opinion of the investigator, should prohibit the participation in the study Serum calcium level >10.5 mg/dl anti-epileptic medication triglycerides > 400 mg/dL BMI > 40 kg/m2 Evidence of cirrhosis as evidenced by AST > 3 x upper limit, ALT > 3 x upper limit, bilirubin > 1.5 mg/dL , albumin < 3.0 g/dL, PT > 14.5 sec Pregnant or Lactating Females

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: placebo<br> | |
| Experimental: Vitamin D3<br>Vitamin D3 given for 8 weeks | Dietary Supplement: Vitamin D3<br>* 50,000 units taken orally once a week for 8 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Small LDL particle concentration |  | Visit 5 |