• LDL-cholesterol [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  

• Vitamin D and metabolite concentrations with supplementation and time course of repletion in deficient or insufficient subjects [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  
• Measures of inflammatory markers [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  

Data from previous trials suggest a protective role of vitamin D in cardiovascular disease. A recent meta-analysis of trials with at least 5 years of follow-up of vitamin D supplementation concluded that intake of vitamin D supplements may decrease total mortality, but that the relationship between baseline vitamin D status, dose of vitamin D supplements, and total mortality rates remains to be investigated. An even more recent analysis of vitamin D concentrations found that participants with vitamin D deficiency and hypertension were about twice as likely as people without hypertension and vitamin D deficiency to have a cardiovascular event during the study.

The main hypothesis to be tested is that oral vitamin D supplementation will lower LDL-cholesterol and total cholesterol concentrations. Subhypotheses are that HDL-cholesterol, triglycerides, lipoprotein(a), hs C-reactive protein and Hemoglobin A1c will not be affected, and that effects will be greatest in persons with vitamin D deficiency or insufficiency in the non-supplemented state.

This is a 12-week study of the effects of supplementation with 1000 IU vitamin D on lipid and vitamin D concentrations. Dietary intake of vitamin D will be estimated by dietary recall questionnaire or analysis of three non-consecutive 24-hour dietary intake logs.