Sunshine - good or bad?

Vitamin D has been getting more attention in recent years, as our understanding of its importance deepens. We’ve always known that severe deficiency disrupts the formation of bones and teeth, leading to rickets in young children and contributing to osteoporosis in the elderly. But not quite getting enough is more difficult to pin down. It can lead to joint pain, muscle fatigue, tiredness and depression, and some nutritionists advise regular supplementation if you live in the northern hemisphere, especially in the winter months.

However, the best way to get your vitamin D is directly from sunlight; it’s how we evolved to absorb it, first and foremost. The trouble is, most of us don’t spend a lot of time outdoors these days, and when we do, we cover ourselves with sunblock in order to prevent skin cancer. Nurseries now demand that children bring sunblock with them, and they always use it. So how much sunlight is enough for vitamin D, and how do we balance that with the cancer risk?

Current NHS guidelines state that for most people in the UK, being out in the sun without sunblock for ‘short periods’ every day between late March and late September, with forearms, hands or lower legs exposed, should be enough. That probably rules a lot of us out straight away, and if your skin is dark, or you are on medications like carbamazepine, phenytoin, primidone or barbiturates, or you live in northern parts of the UK, you’ll need more sun exposure than the rest of us. If you suffer from Crohn’s disease, coeliac disease, or some liver and kidney disorders, you’re also more likely to be vitamin D deficient.

So what can you do? Using a sunblock with a lower sun protection factor is one answer, and so is eating foods that are rich in vitamin D, such as oily fish, red meat and egg yolk. In the UK, margarine and milk are also fortified with vitamin D, and so are some cereals. And if you think you are at risk of deficiency, a supplement – especially during the winter months – is not a bad idea.