Low levels of the sunshine vitamin, D, can trigger high blood pressure, delegates will hear today at a European conference.
Delegates at the European Society of Human Genetics (ESHG) conference in Paris, France, will hear Dr Vimal Karani, from the Institute of Child Health, University College London, who led the world’s largest genetic study to examine the causal association between the two, suggest that some cases of heart disease could be prevented through vitamin D supplements or fortifying foods.
The vitamin is largely made in the body through exposure to sunlight – and deficiency generally means inadequate exposure to daylight.
Data from the D-CarDia collaboration, which involved more than 155,000 participants in 35 studies across centres in Europe and North America, showed that those individuals who had high concentrations of 25-hydroxyvitamin D (25(OH)D) also had reduced blood pressure.
“We knew from earlier observational studies that low 25(OH)D concentrations were likely to be associated with increases in blood pressure, but correlation is not causality,” he says. “Additionally, randomised controlled trials of vitamin D supplementation in humans have produced inconsistent effects on cardiovascular outcomes. The whole picture was somewhat confused, and we decided to try to figure it out once and for all.”
The researchers used genetic variants known as single nucleotide polymorphisms (SNPs) as proxy markers to reflect individual’s vitamin D status to test for a causal association with blood pressure and hypertension.
When the results were analysed, they found that for every 10% increase in 25(OH)D concentrations, there was a 8.1% decrease in the risk of developing hypertension.
Dr Karani used a technique known as Mendelian randomisation to establish that vitamin deficiency seemed to cause high blood pressure.
He said: “Our study strongly suggests that some cases of cardiovascular disease could be prevented through vitamin D supplements or food fortification."
Dr Karani and colleagues now want to continue the work by examining the causal relationship between vitamin D status and other outcomes that are related to heart disease, such lipid-related phenotypes, cholesterol, type 2 diabetes and markers of glucose metabolism.
“We believe that we still have a lot to find out about the effect of vitamin D deficiency on health, and we now know that we have the tools to do so,” he added.
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