Taking a vitamin D supplement daily for a month can cause a drop in blood pressure, dramatically reducing the risk of strokes and heart attacks, research suggests.
The so-called “sunshine vitamin” has long been hailed as beneficial for bone health and crucial in helping us fight disease.
But now researchers in Lebanon, who followed more than 200 obese adults in their 70s, found that it also “significantly” lowered blood pressure in those who took it for a month.
The team found that a 600 IU (or 15 mg) tablet achieved the optimal effect; increasing the dose made little difference in benefit.
High blood pressure is one of the leading causes of death in the country and is responsible for one in four deaths, according to NHS England.
It is often called a “silent” threat because around a third of people with the condition are thought to be undiagnosed, according to the British Heart Foundation.
Not only is it the leading cause of heart disease, but it can also lead to kidney disease and vascular dementia.
However, taking a high dose of the supplement, which typically costs around £4, did not provide any additional health benefits.
Nicknamed the “silent killer”, more than 14 million adults in the UK have high blood pressure, known medically as hypertension.
Now experts believe they have discovered a cheap, low-risk method to treat the problem, which affects blood flow to and from the heart.
In the study, researchers divided 221 adults, with an average age of 71 and a BMI of 30.2 (classified as obese), into two groups.
The first group was assigned vitamin D tablets at 600 international units (IU) per day, the daily dose recommended by the Institutes of Medicine. Most vitamin D tablets available at major pharmacies contain approximately 400 to 800 IU per pill.
The second 110 volunteers were prescribed super-potent tablets of 3,750 IU/day.
After a year of follow-up, the team found that both groups had reduced their blood pressure by 3.5 mm Hg on average.
This is the systolic pressure or the maximum number on a blood pressure monitor. Normal blood pressure is considered to be below 120.
Those who received the highest dose saw their reading drop by 4.2 mm HG on average, and the lowest group experienced a drop of 2.8 mm HG.
But, in a paper in the Journal of the Endocrine Society, they concluded that this difference was small and would have little impact on the change in heart health risk.
Vitamin D, available for £4 at Boots, has long been hailed by experts as beneficial for bone and muscle health.
The vitamin’s main function is to help our bone tissue absorb calcium, which makes the bone stronger and less susceptible to fractures.
Deficiency causes rickets in children and a similar condition, osteomalacia, in adults: softening and weakening of bones that causes pain and deformities.
It is also believed to reduce the risk of type 1 diabetes, respiratory diseases and other ailments.
But Britons of all ages are not getting enough due to contributing factors such as poor diet, not spending enough time outdoors and not taking supplements to make up the shortfall.
The latest UK National Diet and Nutrition Survey reports that between 2008 and 2012, almost a quarter of adults aged 19 to 64 and one in five adults aged 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 expressed in units of nanomoles per liter, written as nmol/l.
A level of 25 nmol/l or less is considered a deficiency; This was established about two decades ago, as falling below that level was linked to an increased risk of rickets.
However, other previous research 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 can also predispose people to painful kidney stones.
