"enjoy sun safely" new vitamin d advice from uk experts

"Enjoy the sun safely", including a few "minutes around the middle of the day without sunscreen", is the cautious new advice from UK experts and organizations to provide clarity on vitamin D because while there are a number of known benefits, there are still too many unanswered questions about the vitamin.

Cancer Research UK, the British Association of Dermatologists, Diabetes UK, the Multiple Sclerosis Society, the National Heart Forum, the National Osteoporosis Society and the Primary Care Dermatology Society released a joint position statement on vitamin D on 16 December.

Ed Yong, head of health information and evidence at Cancer Research UK said the UK joint statement "brings together the latest evidence on vitamin D" and agrees with views of international organisations, such as the World Health Organisation and the US Institute of Medicine.

The statement stresses that "while vitamin D is essential for good bone health, the evidence which suggests it can protect against cancer, heart disease, diabetes, multiple sclerosis and other chronic diseases is still inconclusive".

While some foods contain small amounts of vitamin D, such as oily fish and eggs, as well as fortified foods like margarine, breakfast cereals and powdered milk, we get most of it from exposing our skin to sunlight.

Among the unanswered questions that experts are trying to resolve are what levels of the vitamin count as "sufficient" or "optimal", and what constitutes an appropriate "trade-off" between under and over exposure to the sun.

Under exposure to sunshine is linked to vitamin D deficiency which leads to bone conditions such as rickets in children and osteomalacia and osteoporosis in adults, whereas over exposure is linked to skin cancer, including melanoma, which causes 75 per cent of deaths from skin cancer and is the the fastest rising type of cancer in the UK.

While there is a consensus about what level constitutes deficiency in vitamin D, a standard definition of what constitutes an "optimal level" of vitamin D does not exist, said the statement, and there is no "one-size-fits-all" answer to the sun exposure question.

There have been proposals to raise the definition of deficiency to higher levels, but the statement suggests this would be inappropriate in the absence of randomized trials to show that raising such levels brings clear benefits without risks to health.

Among the questions that the statement suggests we still need answers to are:

  • What is the optimal level of vitamin D for good health and can higher levels directly reduce the risk of cancer and other diseases?
  • Could supplementation achieve the same effect?
  • How much sun exposure ensures optimum levels of vitamin D in people of different skin types and in different environments/circumstances?
  • What role is played by diet and supplements in achieving optimal levels of vitamin D, especially in the winter months?
  • What might be the adverse effects of taking too much vitamin D, either through supplements of fortified foods?
  • Does body fat act as a "sink or source" of vitamin D in winter?
However, in the meantime, the organizations wanted to present a unified view to give some clarity to an otherwise rather murky situation.

Their statement urges people to "enjoy the sun safely and take care not to burn" so as to reap the benefits of making enough vitamin D for health without unnecessarily increasing the risk of skin cancer.

However, it stresses that the time needed in the sun to make enough vitamin is short and less than the time it takes for the skin to go red and burn.

It suggests that:

"Regularly going outside for a matter of minutes around the middle of the day without sunscreen should be enough," and that it is better to do this "little and often" and that "the more skin that is exposed, the greater the chance of making sufficient vitamin D before burning".

"However, people should get to know their own skin to understand how long they can spend outside before risking sunburn under different conditions," it cautions.

The organizations behind the statement do not support the idea of "widespread vitamin D supplementation for the general population" because there is not enough evidence about the effectiveness and potential harms of such an approach.

However, the statement does say that:

"Vitamin D supplements, fortified fat spreads and dietary sources such as oily fish (including salmon, trout and sardines) can be useful for helping to maintain sufficient levels of vitamin D."

"These sources are particularly important during the winter and among people at higher risk of vitamin D deficiency, including pregnant and breastfeeding women, young children, older people, darker-skinned people, those who wear whole-body coverings, those living in institutions, skin cancer patients and those who avoid the sun."

It also suggests that "people at risk of low sun exposure" should follow the Government-recommended dose and take a 10 microgram supplement of vitamin D a day (7 micrograms a day for children aged 6 months to 5 years).

Yong told the press that:

"Avoiding sunburn still remains the most important thing people can do to protect themselves against developing skin cancer."

"By enjoying the sun safely, people can make enough vitamin D without increasing their risk of skin cancer," he added.

-- Consensus Vitamin D position statement (PDF download)

Sources: Cancer Research UK, FSA.

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