Vit D by 10 ng higher iis associated with 4 mg higher HDL 2009
Vitamin D supplementation may improve HDL cholesterol levels   
J Clin Lipidol 2009; Advance online publication
http://www.lipidsonline.org/news/article.cfm?aid=8084 July 2009
MedWire News: Low levels of serum 25(OH)D (vitamin D) are associated with low levels of high-density lipoprotein (HDL) cholesterol and reduced waist circumference, report researchers in the Journal of Clinical Lipidology.
Low levels of vitamin D have previously been associated with markers of cardiovascular disease (CVD) risk, explain Kevin Maki (Provident Clinical Research, Glen Ellyn, Illinois, USA) and team.
In this cross-sectional study, the investigators recruited 257 men and women to assess links between vitamin D level and selected CVD risk markers including components of the metabolic syndrome such as HDL cholesterol, triglycerides, and abdominal obesity.
They also evaluated dietary intake using food frequency and dietary supplement questionnaires.
Maki et al report that HDL cholesterol level significantly increased in a graded fashion, with levels increasing from 48.4 mg/dl to 62.3 mg/dl (1.25 to 1.61 mmol/l) among participants in the lowest and highest tertiles of serum vitamin D, respectively.
Each 10-ng/ml increment in serum vitamin D level was associated with an increase in HDL cholesterol of 3.80–4.20 mg/dl (0.10–0.11 mmol/l) following adjustment for established determinants of HDL cholesterol.
The authors point out that, if confirmed, this finding could have important implications with regard to coronary heart disease, as previous studies have shown that a 1.00 mg/dl (0.02 mmol/l) increase in HDL cholesterol is linked to a 4–6% decrease in risk for the condition.
Of note, each 1-ng/ml increment in vitamin D was associated with a significant 0.31 cm smaller waist circumference. But the researchers say this could be explained by the fact that vitamin D is fat soluble and there is therefore a “greater storage capacity for vitamin D in overweight and obese individuals, which may result in a reduced circulating concentration.”
Other factors such as triglycerides showed a graded inverse relationship with vitamin D level, and metabolic syndrome prevalence decreased significantly from the lowest to the highest tertile.
“These results suggest that clinical trials should be undertaken to assess the impact of increasing vitamin D intake on the metabolic cardiovascular risk factor profile,” concludes the team.
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