We have been blessed with some beautifully sunny days this winter, and from my window I can see bright sunshine in a cloudless sky. Sunlight has been shown to be important for many aspects of our health: for our mental wellbeing, regulating our body clocks, encouraging physical activity and so on.
When the sun’s rays hit our skin they help produce the “sunlight vitamin.” vitamin D, which is vital for building healthy bones. Deficiencies in this vitamin have also been linked to such medical conditions as heart disease, diabetes, rheumatoid arthritis, multiple sclerosis and cancer.
For most fair-skinned adults, 15 minutes of the sun directly on our face and arms (i.e.not through a window or clothes), 2-3 times a week is enough to get an adequate supply of vitamin D. If you have darker skin, more exposure time is needed.
The UK and Ireland’s high latitude means that between October-March the sunlight we are exposed to in is probably not strong enough for any vitamin D to be produced.
There has been concern for some time about rising rates of rickets and osteomalacia in Ireland, and recent research has shown that children and mothers in Ireland have low vitamin D levels.
The HSE has recently published new guidance that advises parents to give their infants 5 micrograms (5 μg) of vitamin D3 every day from birth until they reach a year old, whether they are breast or bottle-fed. This comes in liquid form given by dropper, and is available in most pharmacies. You don’t need a prescription. There are multivitamin preparations with D3 in them but these should not be given unless specifically advised by your baby’s doctor. Like all vitamins, D3 can be harmful if given in very high doses, but you would have to give at least five times the supplemental dose for a period of time to cause any ill effects.
Other people at risk of vitamin D deficiency include pregnant women, nursing mothers, dark-skinned people, under-5’s over-65’s, those who are housebound, and people who keep their skin covered for cultural reasons.
Dietary sources of vitamin D - which include oily fish, eggs, and fortified cereals – are of course useful, but, like the Irish sun in winter, unlikely to provide adequate vitamin D. There is as yet no official guidance in Ireland for dietary supplementation other than in infants, but other countries at the same latitude as us, including the UK and Canada, recommend dietary supplements for all high-risk groups. Ireland may well follow suit soon.
But before you head off for a week at the beach citing bone health as your reason for sunbathing all day, please remember that prolonged sun exposure – even in the UK and Ireland – significantly increases your risk of skin cancer. So a balance is needed between too much sun and not enough. And don’t forget that many moisturizers have sunscreen built-in, which will block our precious winter sunlight. To avoid vitamin D deficiency, the best advice is: get the right amount of sun when you can, eat oily fish and take a vitamin D supplement.
HSE Guidance for parents is available online: http://www.hse.ie/go/vitaminD