Is there a relationship between vitamin D levels and cholesterol?

Question

I've been trying to read up on high cholesterol and there is a lot of information out there about it. In addition to "don't eat fatty foods" and "exercise more," there are some sources that mention vitamin D as a possible contributor to improving cholesterol levels.

The test group received a daily dose of 1,000 mg of elemental calcium along with 400 IUs of vitamin D3....

Blood levels of vitamin D, fasting plasma triglycerides, HDL, and LDL cholesterol levels were assessed at the beginning and end of the trial. After two years, women who received the vitamin D and calcium supplements had a 38 percent increased mean vitamin D level compared to the placebo group.

They also had a 4.46-mg/dL mean decrease in LDL. Furthermore, higher vitamin D concentrations were associated with higher HDL combined with lower LDL and triglyceride levels.

Edit:

The quote was originally from Mercola, but, the article seems no longer to exist. However, the originating study seems to be Schnatz, et al. (2014)

It looks like there is a correlation, but I'm curious how that works.

References

Schnatz, P. F., Jiang, X., Vila-Wright, S., Aragaki, A. K., Nudy, M., O'Sullivan, D. M., Jackson, R., LeBlanc, E., Robinson, J. G., Shikany, J. M., Womack, C. R., Martin, L. W., Neuhouser, M. L., Vitolins, M. Z., Song, Y., Kritchevsky, S., & Manson, J. E. (2014). Calcium/vitamin D supplementation, serum 25-hydroxyvitamin D concentrations, and cholesterol profiles in the Women's Health Initiative calcium/vitamin D randomized trial. Menopause, 21(8), 823–833. https://doi.org/10.1097/GME.0000000000000188

Answer 1

According to a couple of systematic reviews of studies, there is insufficient evidence about the lowering effect of vitamin D on blood cholesterol levels.

1. Vitamin D, Evidence Mayo Clinic (data from Natural Standard Research Collaboration)

Many studies have looked at the effects of vitamin D alone or in combination with other agents for high cholesterol, but results are inconsistent. Some negative effects have been reported.

2. Zitterman A et al, 2011, The role of vitamin D in dyslipidemia and cardiovascular disease [a systematic review] (PubMed)

The vast majority of intervention studies did not show an effect of vitamin D on serum cholesterol levels.