Vitamin D dilemma

Lesley Dobson / 12 June 2014 ( 16 October 2015 )

How much sunlight is enough to top up your vitamin D? How long should you expose your skin to the sun? We look at sources of vitamin D and vitamin D deficiency symptoms.

Unless you’ve had your head buried firmly in the sand for years, you’ll have read, often, that getting sunburnt is bad for you. Figures from Cancer Research UK show that the rates of malignant melanoma - the most dangerous type of skin cancer – are now five times higher than they were 40 years ago. More than 13,000 people a year are being diagnosed with malignant melanoma in the UK.

Vitamin D deficiency

On the other hand, you have probably read, or heard, that having low levels of vitamin D affects the strength of our bones. The National Institute for Health and Care Excellence (NICE), Centre for Public Health recently confirmed that vitamin D deficiency is a cause for concern. NICE has recently released figures showing that one in five adults are vitamin D deficient, and there is an increased risk of this in children too.

“Vitamin D is absolutely essential for bone health,” says vitamin D expert Lesley Rhodes, Professor of Experimental Dermatology at the University of Manchester. “And that’s throughout our lifespan, from young children, through to older people, when it’s very important to maintain good musculoskeletal function. Vitamin D is an important part of that.

This is where we face a dilemma. Getting sunburnt increases our risk of developing skin cancer. But the best way to get enough vitamin D into our systems is by exposing our skin to the sun, and its UVB (Ultra Violet B rays). “It’s a paradox,” says Professor Rhodes. “UVB is the only wavelength responsible for vitamin D, but it’s also the one responsible for burning and skin cancer.”

Find out more about the effects of vitamin D on your health

How much time should we spend in the sun?

“Our work suggests that spending around 15 minutes a day, on most days of the week, when the sun is reasonably strong, results in sufficient vitamin D levels in the majority of fair-skinned people. But it is important that you don’t let your skin go red, so you do have to gear your sun exposure to your own skin.”

Yinka Ebo, senior health information officer at Cancer Research UK agrees. “You should spend some time in the sun, but our key message is ‘avoid sunburn’, that’s because sunburn is a clear message that the DNA in our skin has been damaged by too much UV radiation. Over time that damage can build up and give us skin cancer.”

New research, carried out at Cancer Research UK’s Manchester Institute, at the University of Manchester, has found that sunscreen alone is not enough to protect us from malignant melanoma. “UV light targets the very genes protecting us from its own damaging effects, showing how dangerous this cancer-causing agent is,” explains Professor Richard Marais, study author and Cancer Research UK scientist.”

“Very importantly, this study provides proof that sunscreen does not offer complete protection from the damaging effects of UV light.”

“This work highlights the importance of combining sunscreen with other strategies to protect our skin, including wearing hats and loose fitting clothing, and seeking shade when the sun is at its strongest.” 

10 reasons to get outdoors more

Vitamin D without burning

Vitamin D is vital for our bone health, and the best sources are UVB rays from sunshine. To get enough vitamin D without burning and raising your risk of skin cancer:

  • Spend about 10 to 15 minutes in the sun, with bare legs and arms (and no sunscreen), twice a day.
  • Adjust the time you spend in the sun depending on your skin type – those with fair skin burn more quickly than those with dark skin. People with darker skin may need a little more time in the sun, but must still make sure not to burn.
  • Avoid allowing your skin to burn – or even to turn pink
  • UVB rays are strong enough to help us make vitamin D from May to September
  • You need to go outside – your body can’t produce vitamin D if you sit inside by a window.

Don't take risks with the sun - read our guide

Should you take vitamin D supplements?

Certain groups of people are more likely to be at risk of low vitamin D levels. If you don’t get outside very much, because you:

  • Are infirm or unwell
  • Have a sun allergy (photosensitivity), that makes it hard to go out in the sun
  • Wear clothes that fully conceal you
  • Have naturally dark or black skin
  • Are pregnant

Then you’re more likely to be vitamin D deficient.

“There is some evidence that as we get older we may not synthesise vitamin D as well as we do in our younger years,” says Sarah Leyland, Senior Nurse and Helpline Manager at the National Osteoporosis Society.

“Current UK Government recommendations are that certain at risk groups, (as shown above) should consider taking a supplement. There is a suggestion that we should be getting 10 micrograms or 400 international units a day. If we can’t get that through sun exposure and our food, then we need to be taking a daily supplement.”

It is worth knowing that vitamin D3 is probably preferable to vitamin D2, as it may be slightly more effective.

Foods with vitamin D

There aren’t many foods that contain vitamin D. The best sources are oily fish – mackerel and salmon, for instance, eggs and fortified fat spreads. Vitamin D is also in fortified breakfast cereals and powdered milk. Check the labels to make sure the brand you’re buying is fortified with vitamin D.

Discover 10 reasons to eat more eggs

Learn 10 reasons to eat more fish

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.