Optimal blood vitamin D levels may reduce mortality linked to cardiovascular disease

The risk of dying from cardiovascular disease may be decreased if people with metabolic syndrome have vitamin D blood concentrations of at least 75 nmol/L, says a new study from Europe.

In the cohort study, blood samples of 1,801 people with the metabolic syndrome were analyzed for vitamin D concentrations, and deaths (all-cause and cardiovascular disease mortality) were documented over an average of 7.7 years (1). The study results showed that optimal levels of vitamin D (at least 75 nmol/L) were associated with a 66% reduction in the risk of cardiovascular disease mortality, compared with people who suffer severe vitamin D deficiency. In addition, all-cause mortality was reduced by 75% in people with optimal vitamin concentrations. For specific cardiovascular disease mortality, there was a strong reduction for sudden death (85% reduction) and congestive heart failure (76% reduction), but not for myocardial infarction.

The researchers concluded that they hope these findings will spur randomized controlled trials to confirm the positive effects of vitamin D on mortality and help establish recommendations for supplementation for patients with metabolic syndrome. Commenting on the potential mechanism, the scientists said that vitamin D is known to affect blood sugar regulation, and that low vitamin D levels have been linked to increased insulin resistance. In addition, vitamin D may also protect the walls of blood vessels via anti-inflammatory effects.

Metabolic syndrome is a condition characterized by central obesity as the main risk factor, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type-2 diabetes and cardiovascular disease. Fifteen percent of adult Europeans are estimated to be affected by metabolic syndrome, while the US statistic is estimated to be 32 percent.

1. Thomas G. N. et al. Vitamin D levels predict all-cause and cardiovascular disease mortality in subjects with the metabolic syndrome: The Ludwigshafen Risk and Cardiovascular Health (LURIC) study. Diabetes Care. 2012; 35:1158–1164.