Sunbathing can make you live longer!
“I’m busy making vitamin D. I’ll do it later” has been my excuse for lying in the sun doing nothing this weekend. Yes it was an excuse to be lazy but there is some truth in my argument. But how long do we actually need to spend in the sun and do we still need to supplement vitamin D in the summer?
Why is it so important?
Studies are increasingly showing that the higher your vitamin D level, the lower your risk for many diseases including cardiovascular disease, cancer, respiratory infections and diseases, tuberculosis and diabetes. Together these account for about 60 percent of all deaths in any given year. It’s becoming clear that getting enough vitamin D is very important to health and longevity.
A major study by leading vitamin D expert Dr William Grant, found that increasing your levels of vitamin D would cut premature deaths by 21 percent, and extend your healthy lifespan by over two years. Dr Grant estimates that for the average European, blood levels of vitamin D are around 54nmol/L. Upping levels to 100nmol/L would be sufficient to lower mortality from a whole range of conditions. Disturbingly, levels are often found to have dropped below 35nmol/L in winter. This is the time we need it most as its critical to the proper functioning of the immune system.
How much do we need?
This is the tricky bit as we are all unique in our ability to make vitamin D. You can test your levels through your GP or a home-test kit to really know, but statistics show that most people are deficient and some critically so without even knowing. The amount we need is the amount that gets us in the right range of 100-125 nmol/L. It’s difficult to assess individual needs, given variations in sunlight exposure, skin colour, diet, lifestyle and factors such as liver disease and obesity. But in general, it takes about 3,000 to 5,000iu’s a day for most people to reach the optimum level.
Where can we get it from?
There are three ways to up your blood level of vitamin D – eat it, supplement it or expose yourself to sunlight. The best dietary sources are fish, eggs, dairy and fortified foods such as some milk or yoghurt. But you can’t really get enough through diet alone.
A serving of oily fish provides around 350ius of vitamin D, an egg has around 20 ius. A glass of fortified milk can contain 100ius but you’d have to eat an unhealthy and unrealistic amount of these foods to boost levels. So I also take supplements, especially in winter. You can buy great vitamin D drops which contain 1000ius per drop.
Sunlight exposure – getting the balance right
When done correctly we can maximize vitamin D using sunlight without damaging our skin. From late spring to early autumn, we can make 1,000-4,000iu’s per day from 15-30 minutes of sun exposure around midday (you need to expose as much of your body as possible). After that, the body starts breaking down vitamin D to protect you from making too much. People with darker skin, the elderly and overweight people need to spend a little longer as it takes them more time to make vitamin D.
Its the UVB rays that generate vitamin D, whilst UVA overexposure promotes skin damage and increased melanoma risk. It is still important to protect your skin in the sun so it’s worth using sunscreen after the initial period. It’s also worth remembering that sunlight only damages skin cells when vitamin A is depleted. Eating foods rich in this vitamin (mangos, carrots, broccoli, sweet potatoes, spinach, apricots) and ensuring you have lots of antioxidants in your diet helps combat some of the dangers of sun overexposure. One study even showed that three cups of green tea a day protected the skin from UV damage.
One of the best ways to protect yourself from the dangers of UVA rays, but not completely block your ability to make vitamin D, is to apply a vitamin-rich cream before and after sun exposure.
Mushrooms should sunbathe too: Here’s my favourite bit of new research. Mushrooms placed in direct sun between 10 am and 3pm for up to an hour can make vitamin D. Amazing, and we’re talking any variety of mushrooms. One portion of sun-exposed mushrooms gives around 400ius. Cooking doesn’t destroy the nutrient so it’s a great way to boost your levels.
So I do still supplement in the summer unless I’m on holiday. Living in London realistically there aren’t that many days that are cloud or pollution-free (both block UVB). Also its not always practical to lie out in the sun at peak hours. I try to get my kids out in the sun too but am careful to cover them up after about 20 minutes to protect from sun damage. As we’re designed to make 90 percent of our vitamin D through sunshine, it makes sense to make use of the sun when we can and its the perfect excuse for a little laziness!
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