The Sunshine Vitamin
Are you getting enough vitamin D? It could make a big difference to your health.
Its power to strengthen bones and muscles has been well known for years. But now there's increasing evidence that this vitamin D may exert a positive influence over many other parts of the body.
New Danish research has confirmed that vitamin D - known as the 'sunshine vitamin' because 90% of it is made in the skin when it's exposed to sunlight - can help lower blood pressure.
The study on 112 patients in Denmark found that taking a vitamin D supplement led to a "significant reduction" in blood pressure.
And just last week, anoher study found that the children of women who were deficient in vitamin D during pregnancy were fatter as they grew older than children born to women who weren't vitamin D deficient.
The studies add to a growing body of research which suggests vitamin D may keep the immune system healthy, and reduces the risk of some cancers, while being deficient in the vitamin may increase the risk of chronic health conditions such as multiple sclerosis, diabetes and cardiovascular disease.
Professor Cyrus Cooper, says that in the last 10 years there's been an increasing amount of research into vitamin D and health problems such as diabetes, obesity, blood pressure, heart disease, auto-immunity and multiple sclerosis.
"There's been a lot linking vitamin D in observational data with all those outcomes," he says.
"They're interesting, because the vitamin D receptor is found on lots of different cell types, including cells of the immune system, the vascular system and smooth muscle, so it's conceivable that it has cardiovascular, immune and other effects."
Cooper says people should be aware of how to get vitamin D - mainly from exposure to UVB rays from sunlight in the summer months and, to a much lesser extent, eating oily fish.
Currently, people are spending less time outdoors; sunscreen is often applied when it's sunny, preventing the synthesis of vitamin D in the skin, and more people are keeping their skin covered for cultural reasons.
You're unlikely to know you have low vitamin D levels without having a blood test, as the effects tend to become apparent over the longer term.
As well as the health implications currently being researched, like multiple sclerosis, high blood pressure and obesity, it's known that vitamin D ensures people absorb enough calcium to keep bones and teeth healthy, so low levels can lead to brittle bones and osteoporosis.
Children with low levels of vitamin D are also at risk of the bone-weakening disease rickets, known for causing bow legs.
They can even be born with the condition if their mother has vitamin D deficiency during pregnancy,
Cloudy skies mean the skin produces less vitamin D, and for this reason in Ireland people usually only make it over the summer months, from about the end of April until October, and between around 10am and 3pm.
Pollution, sunscreen and clothes also reduce the amount of vitamin D produced.
The vitamin can be stored in the body for up to three months, and ideally people make enough over the summer to get them through the winter.
DO YOU GET ENOUGH VITAMIN D?
you get outside regularly - for around 15 minutes a day in the summer?
Are your face, arms and/or legs exposed to the sun when you go outside?
Do you eat a diet rich in vitamin D, including oily fish (eg salmon, sardines, trout) at least once a week? Smaller amounts of vitamin D are also found in eggs and meat, and it's added to margarine, some breakfast cereals and infant formula.
If you don't get enough vitamin D from natural sources, do you take a supplement?