If you needed another reason to moan about the Irish weather – US vitamin D specialist Dr Michael Holick is the man to talk to.
The professor of Medicine at Boston University Medical Center and author of The Vitamin D Solution believes Ireland’s lack of sunshine, needed to stimulate the production of vitamin D in the body, is making us all less healthy.
Known as the “sunshine vitamin”, it not only helps us absorb up to twice as much calcium from our food for good bone health, but Holick says it can also play a role in everything from labour pains to multiple sclerosis.
The modern lifestyles “of avoiding the sun, putting on sun screen and working indoors” is thwarting Mother Nature, something that’s further exacerbated by Ireland’s northerly latitude, says Holick.
“You get no Vitamin D in Ireland from November through March,” he says. “The sun is coming in at an angle at that time of year and the vitamin D producing rays are being absorbed by the ozone layer.”
Our summers aren’t much good either, according to Holick, particularly if we’re being sun smart. “If you go out in the early morning and late afternoon as you’ve been taught, you get no vitamin D in summer either because the sun is coming in just like winter sunlight.”
So how does he explain sunburn at these off-peak times? “UVA radiation makes no vitamin D, but it can still cause redness to the skin – it’s not UVA rays you’re after, it’s UVB and it mainly comes in from 10am to 3pm.”
Before sun-worshippers take Dr Holick’s words as carte blanche to hit the garage roof with some reflective foil and a slick of baby oil, he urges caution.
“Get out for five or 10 minutes, protect your face because it’s the most sun damaged – but exposing your arms or legs a couple of times a week won’t cause any problems and will definitely improve your vitamin D status.”
So what can the sunshine vitamin do for us? “We’ve shown that pregnant women who are vitamin D deficient in their first trimester have a higher risk of vaginal infection and of pre-eclampsia,” he says.
“We did a study of 400 women to see if vitamin D levels had an effect on the numbers requiring C-section – we found a 400 per cent reduced risk of a C-section if they simply were vitamin D sufficient at the time they gave birth.”
Holick says a deficiency of the vitamin in utero and in the first year of life brings a higher risk of eczema and wheezing disorders and also impairs growth.
He says “there’s no food that naturally contains vitamin D other than oily fish. It’s mainly in foods especially fortified with vitamin D, like milk.”
For pregnant women, he advises pre-natal vitamins containing vitamin D and two glasses of D-fortified milk a day.
There are also benefits for teens, he says. “There’s data in the US that teenagers who are D deficient have over twice the risk of having high blood pressure and four times the risk of having type 2 diabetes.”
Holick claims vitamin D can also have a powerful effect on multiple sclerosis (MS) and again draws a parallel between our geographic location and the disease.
“We know that if you live north of Atlanta Georgia, so basically all of northern Europe, for the first 10 years of your life, you have a 100 per cent increased risk of getting MS for the rest of your life,” he says.
Holick agrees that he gets a certain amount of criticism from skin cancer lobbyists for his pro-sun advice.
“I do get criticism, but I can tell you that 40 per cent of Australians are vitamin D deficient – it turns out the ‘Slip, Slop, Slap!’ campaign has caused a major epidemic in vitamin D deficiency.
“Even the Australian Cancer Council and the Australian Dermatology Association have now recommended some sensible sun exposure.”
This wonder vitamin might just be good for government coffers too, according to Holick. He believes that Ireland’s annual healthcare budget could be decreased by up to 25 per cent if we all had higher levels of vitamin D.
Let’s hope for a fine summer then.