Taking one vitamin D supplement daily for a month can trigger a drop in blood pressure — slashing the risk of strokes and heart attacks, research has suggested.
The so-called ‘sunshine vitamin’ has long been hailed as beneficial for bone health and crucial for helping us fight off diseases.
But now researchers in Lebanon, who tracked more than 200 obese adults in their 70s, found it also ‘significantly’ lowered blood pressure in those who took it for a month.
The team found that one tablet of 600 IU (or 15mg) achieved the optimum effect — increasing the dose made little difference to the benefit.
High blood pressure is one of the nation’s biggest killers, responsible for one in four deaths, according to NHS England.
It is often referred to as a ‘silent’ threat because roughly a third of those with the condition are thought to be undiagnosed, according to the British Heart Foundation.
Not only is it the leading cause of heart disease, it can also lead to kidney disease and vascular dementia.
Taking a high dose of the supplement, which typically costs around £4, did not however provide any additional health benefits
Dubbed a ‘silent killer’, more than 14 million adults in the UK have high blood pressure — known medically as hypertension
Now experts have believe they may have discovered a cheap and low-risk method of treating the problem, which affects blood flow to and from the heart.
In the study, the researchers split 221 adults, aged 71 on average with a BMI of 30.2 (classed as obese), into two groups.
The first group were assigned vitamin D tablets of 600 international units (IU) per day — the recommended Institutes of Medicine daily dose. Most vitamin D tablets available from high street chemists contain roughly 400-800 IU per pill.
The second 110 volunteers were prescribed super strength 3,750 IU/day tablets.
After a follow-up of a year, the team discovered both groups had decreased their blood pressure by 3.5mm Hg on average.
This is the systolic pressure or top number on a blood pressure monitor. Normal blood pressure is considered to be below 120.
Those on the higher dose saw their reading fall by 4.2mm HG on average, with the lower group experiencing a drop of 2.8 mm HG.
But, writing in the Journal of the Endocrine Society, they concluded that this difference was small and would have little impact on change in heart health risk.
Experts have long hailed vitamin D — available for £4 from Boots — as beneficial to bone and muscle health.
The primary role of the vitamin is to help tissue in our bones absorb calcium, making the bone stronger and less suseptible to breakages.
Deficiency leads to rickets in children, and a similar condition, osteomalacia, in adults — softening and weakening of the bones that causes pain and deformities.
It is also thought to lower the risk of type 1 diabetes, respiratory diseases and other ailments.
But Britons of all ages are not getting enough of it with contributory factors including poor diet, not spending enough time outdoors and failing to take supplements to top up the shortfall.
The latest UK National Diet and Nutrition Survey reports that between 2008 and 2012, nearly a quarter of adults aged 19 to 64 and one in five adults over 65 had inadequate levels in their blood.
The amount of vitamin D in the body can be determined by a blood test – and the results are reported in units of nanomoles per litre, written as nmol/l.
A level of 25 nmol/l or lower is considered a deficiency – this was set about two decades ago, as falling below it was linked to an increased risk of rickets.
Other previous research, however, has suggested that taking too many vitamin D supplements could lead to hypercalcemia, a condition in which too much calcium builds up in the blood, potentially forming deposits in the arteries or soft tissues.
It may also predispose people to painful kidney stones.