Vitamin D supplements may not improve cholesterol: Study

The study – published in Arteriosclerosis, Thrombosis and Vascular Biology​ – suggests that correcting vitamin D deficiencies with high doses of oral vitamin D supplements has no effect on cholesterol levels. The findings of the study are contrary to previous research conclusions that have touted the potential of mega-doses of the sunshine vitamin as a way to aid cholesterol management.

Led by Dr Manish Ponda at The Rockefeller University, USA, the researchers found that correcting vitamin D deficiencies with high doses of oral vitamin D3 supplements did not change cholesterol levels, despite effectively increasing vitamin D to recommended levels.

"Our study challenges the notion that vitamin D repletion improves cholesterol levels"​ said Ponda. "These clinical trial results confirm those from a recent data mining study." ​

He said that the findings question the use of vitamin D supplements to improve cholesterol.

Study details​

The researchers studied 151 people with vitamin D deficiency who received either a mega-dose (50,000 internationals units) of vitamin D3 or placebo weekly for eight weeks. Participants' cholesterol levels were measured before and after treatment.

Ponda and his colleagues revealed that vitamin D levels nearly tripled in the group that received supplements, but were unchanged in the placebo group. However, they said that compensating for this vitamin deficiency did not improve cholesterol management in the short-term – as had previously been suggested.

The team also tested the effect of vitamin D supplementation on more sophisticated biomarker measures of cholesterol, including particle size and number.

"These measures of cholesterol, which are not used in routine clinical practice, also did not change in response to vitamin D therapy,"​ said Ponda.

In addition replenishing vitamin D levels decreased parathyroid hormone levels and increased calcium levels, said the authors – who noted that such changes are linked to participants' increase in low-density lipoprotein (LDL) cholesterol.

"For example, participants receiving vitamin D who had an increase in calcium levels experienced a 7 percent increase in LDL cholesterol, while those whose calcium levels fell or did not change had a 5 percent decrease in LDL cholesterol,"​ Ponda said.

However, they said that longer-term studies on the impact of the changes in LDL cholesterol as a result of high dose vitamin D supplementation are needed to make stronger recommendations.