Vitamin D may boost heart health during weight loss

Supplements of vitamin D may improve cardiovascular health during weight loss, without impacting on how many pounds are shed, suggests a new study. German researchers report that a daily dose of vitamin D was associated with lower levels of triglycerides and markers of inflammation like tumour necrosis factor-alpha (TNF-alpha).

“The results indicate that a vitamin D supplement of 83 micrograms/d…is able to significantly improve several cardiovascular disease risk markers in overweight subjects with inadequate vitamin D status participating in a weight-reduction program,” wrote the authors, led by Dr Armin Zittermann from the Clinic for Thorax and Cardiovascular Surgery in Bad Oeynhausen.

Dr Zittermann and his co-workers recruited 200 healthy overweight people with average 25(OH)D levels of 30 nmol/L (12 ng/mL) and randomly assigned them to receive either placebo or vitamin D for one year. All the subjects also participated in a weight-reduction program. At the end of the study, 25(OH)D levels increased in the D group by 55.5 nmol/L, but by only 11.8 nmol/L in the placebo group. Furthermore, a 26.5% reduction in levels of parathyroid hormone was observed in the D group, compared with 18.7 per cent in the placebo group. “High blood concentrations of parathyroid hormone…are considered new cardiovascular disease risk markers,” explained the authors.

Improvements in triglycerides levels were also observed in the vitamin D group, with a 13.5% decrease noted compared with a 3.0% increase in the placebo group.

Finally, levels of the marker of inflammation TNF-alpha decreased by 10.2% per cent following vitamin D supplementation, compared with 3.2% in the placebo group.

“The beneficial biochemical effects were independent of the loss in body weight, fat mass, and sex,” noted the researchers. The study is published in the May 2009 issue of the American Journal of Clinical Nutrition.