Vitamin D ineffective for lowering blood pressure
Although vitamin D has many health benefits, the "sunshine vitamin" won't help lower blood pressure, according to a new study.
Led by Dr. Miles Witham of the University of Dundee in Scotland, researchers reviewed data from 46 clinical trials involving over 4,500 participants. The team also reviewed 27 other studies that involved nearly 3,100 participants. The search period spanned January 1, 1966 through March 31, 2014. The researchers found no evidence that increasing vitamin D levels had any effect on the systolic or diastolic numbers on a blood pressure reading. The systolic (top) number measures the pressure in the arteries when the heart beats and the diastolic (bottom) number measures the pressure in the arteries between heartbeats.
"Large studies have shown that people with low vitamin D levels tend to have higher blood pressure," said Dr. Witham. "It hasn't been clear though whether giving vitamin D to people actually lowers their blood pressure as individual trials have been too small to find out the answer."
The findings were published online in JAMA Internal Medicine.
A 2013 study presented at the annual conference of the European Society of Human Genetics (ESHG) suggested that not getting enough vitamin D could trigger high blood pressure. Researchers found that, for every 10 percent increase in 25 (OH)D -- the chemical name for vitamin D -- concentrations, the risk of developing high blood pressure decreased by 8.1 percent.
High blood pressure isn't the only condition vitamin D may not help treat. A 2014 study published in the journal Psychosomatic Medicine found that vitamin D supplements are likely no help for depression, despite previous research suggesting that depression is linked to low vitamin D levels. Research has not shown whether low vitamin D levels cause depression, or whether low vitamin D levels develop because someone is depressed. People who suffer from depression may stay indoors and receive little exposure to sunlight, which the body uses to produce vitamin D.