Monday, June 17, 2013
Vitamin D Can Help Prevent Hypertension
The world's largest study to examine the link between vitamin D levels and hypertension has found that low levels of Vitamin D can be a major cause of hypertension.
Researchers presented their findings at the annual conference of the European Society of Human Genetics (ESHG).
Data were gathered from 35 studies, which included more than 155,000 participants from different parts of Europe and North America.
Dr. Vimal Karani S, from the Institute of Child Health, University College London, London, UK, led the study.
Participants with high levels of 25-hydroxyvitamin D (25(OH)D) had reduced blood pressure and were at a lower risk of developing hypertension.
Dr. Vimal Karani S, said:
"We knew from earlier observational studies that low 25(OH)D concentrations were likely to be associated with increases in blood pressure and hypertension, but correlation is not causality.
Additionally, randomized 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."
To measure the individuals' vitamin D status and test for an association with blood pressure, the researchers used genetic variations called single nucleotide polymorphisms, or SNPs as proxy markers.
For every 10% increase in 25(OH)D concentrations the researchers noted the risk of developing hypertension decreased by 8.1%.
Dr. Karani S., said that the approach they followed, called Mendelian randomization, allowed them to make accurate conclusions, "by using this approach we can determine the cause and effect and be pretty sure that we've come to the right conclusion on the subject."
The researchers said that Vitamin D deficiency is a very common problem in the Western world, particularly because obesity can cause Vitamin D deficiency and obesity levels are highest in Western countries, according to a study published in a recent issue of PLoS Medicine
People with high levels of vitamin D in their blood enjoy several benefits, apart from improved bone health. Researchers from Boston University School of Medicine reported in PLOS ONE that people with high levels of vitamin D have significantly better immunity and a reduced risk of several diseases.
Vitamin D insufficiency (between 21-29 ng/mL) and vitamin D deficiency (<20 ng/mL) lead to a heightened risk of:
Dr. Karani said that the study provides further data to support the importance of vitamin D. It suggests that vitamin D supplements or food fortification can significantly reduce the risk of cardiovascular disease.
"We now intend to continue this work by examining the causal relationship between vitamin D status and other cardiovascular disease-related outcomes such as lipid-related phenotypes, for example,cholesterol, inflammatory markers such as C-reactive protein, and 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."