The bare necessities: get out in the sun and boost your vitamin D levels

Basking in the sunshine is such a lazy and enjoyable way to pass the time, it’s hard to believe it can do much for your health other than make you feel good. But the truth is that, much like plants, we need sunshine to thrive.

A lack may show up first as tiredness, joint pain, stiffness, backache, cramps and hair loss

Simply allowing the sun’s rays on to your bare skin lets your body create vitamin D, which is essential if we are to have strong bones, teeth and muscles. A lack may show up first as tiredness, joint pain, stiffness, backache, cramps and hair loss.

Studies in Ireland have shown that vitamin D deficiency is widespread, according to the Food Safety Authority of Ireland. Even small changes in latitude can make a difference, giving Kerry an advantage, for example.

“Many large-scale studies show an association between low levels of vitamin D and adverse health outcomes, such as cancer and autoimmune diseases,” says Dr Maria O’Sullivan, associate professor in human nutrition at Trinity College Dublin. “They do not prove causality – that may be down to other factors – but there is a lot of investigation being done into this now. Vitamin D may have a role beyond bone and there are biological reasons to support this, such as many cells have receptors for vitamin D.”

Having low levels is associated with chronic fatigue, multiple sclerosis, some cancers, rheumatoid arthritis, depression and other mental disorders. A report in the British Journal of Cancer from 2014, for example, states: "Our findings suggest that high vitamin D status is weakly associated with low breast cancer risk but strongly associated with better breast cancer survival."

Calcium absorption

What is known is vitamin D promotes calcium absorption in the gut, and without it bones can become thin, brittle and misshapen. A deficiency is linked to rickets in children and osteoporosis in later life. It is a long time since the sight of children with the bowed legs and knock knees that indicate the presence of rickets was common but a study published in the Lancet in 2014 indicates the disease is on the increase in the UK again.

"Hospitalisation rates for rickets in England are now the highest in five decades," the report notes. It has also re-emerged in Ireland in recent years. That is alarming because it is in childhood and early adulthood the body needs to build bone.

“English studies are very relevant to Ireland because we are on the same latitude,” says Dr O’Sullivan. “We get similar levels of sunshine here.”

There is no need to let your skin tan or burn to benefit from the sun, according to the Vitamin D Council, a non-profit organisation in California. "You only need to expose your skin for around half the time it takes for your skin to begin to burn."

So a little laziness actually can be beneficial. Those few minutes spent settling down at the beach, taking out your book and rummaging for suncream may be enough to top up your stores of vitamin D.

“In Ireland, about 10-20 minutes of sun exposure on fair skin is all that is needed,” says Dr O’Sullivan. How much is produced from sunlight depends on the time of day, where you live in the world and the colour of your skin. Lighter skin is more efficient at making vitamin D.

Don’t ditch the factor 40 or force kids to get rid of their wetsuits; just soak up a little sun first. Melanoma is still a concern.

Fog was once blamed for preventing kids from getting enough sunshine. Now it is more likely to be YouTube, Snapchat or the latest game. The same goes for adults who spend the days working indoors at computers and their evenings in front of another screen at home.

The advice is to expose about 20 per cent of your skin for about 30 minutes. If you uncover only your hands and face, that adds up to just about 5 per cent. If it is cloudy, that reduces the level too.

Eat up

Sitting inside a window or a conservatory may feel good, but it won’t help. You have to get outside where your skin can synthesise the vitamin in response to the UVB in sunlight. Even doing so in winter can help.

It's not all about sunlight, however. You can also top up your vitamin D levels through eating such foods as salmon, mackerel, herrings, eggs and fresh or dried mushrooms. There's some in kidneys, liver and butter too. "If you expose yourself to moderate sunlight for 30 minutes a day and eat eggs and oily fish, you might achieve 15mcg [micrograms]," writes British nutritionist Patrick Holford in Good Medicine.

Currently, the recommended supplementation in Ireland is 5mcg per day for those aged 5-50 years and 10mcg for those over 50, as it was in England until the publication of a recent report from the Scientific Advisory Committee on Nutrition. The recommended level there is now 10mcg for most people as it is in Scandinavian countries.

In Ireland 74 per cent of adults and 88 per cent of primary school children have less than half of the recommended daily amount of vitamin D, according to the Irish Osteoporosis Society. Being fat-soluble, it can be stored in the body but we burn through those stores during dark winters.

“This is a good time to think about the topic because vitamin D levels in the blood are often lowest around now after a long winter,” says Dr O’Sullivan.

Those who have fears or suspicions that they are low on vitamin D can get the doctor to do a simple blood test to find out. The doctor may put you on supplements to bring you back to healthy levels. It can take a few months and needs to be monitored carefully.

It’s not easy to get too much vitamin D, unless you supplement with high doses for a number of months. But it is possible. Far better to check with your doctor if you are concerned. Whatever you do, though, make sure to get out into the sun regularly and maintain a good diet.

How to boost vitamin D levels

Get outside regularly

Let the sun hit bare skin

Eat vitamin D-rich foods

Rose Costello is a journalist, fitness instructor and health coach, who works with people one-to-one and in groups to help them to lose weight and get healthy. See zest4life.com