Wearing sun cream does NOT stop the body from producing vitamin D

May 9, 2019 dailymail, health

Wearing sun cream does NOT stop the body from producing vitamin D, finds myth-bunking study

Vitamin D – known as the sunshine vitamin – is essential for bone health
It is produced by the skin in response to ultraviolet radiation from sunlight
UV rays are a major cause of a skin cancer, a common type of cancer
There has been a lot of uncertainty about the effects of sunscreens on vitamin D

Wearing sunscreen does not prevent the body from producing vitamin D, researchers have found.

Health experts say the study will help persuade people to protect themselves from skin cancer, and dismiss the myth that sunscreen prevents vitamin D sufficiency.

Vitamin D – known as the sunshine vitamin – is essential for bone health. It is produced by the skin in response to ultraviolet radiation from sunlight.

However, as well as being the primary source of vitamin D, UV rays are a major cause of a skin cancer, the UK’s most common type of cancer.

Global concern about vitamin D deficiency has triggered debates on how best to achieve healthy levels while simultaneously limiting the risk of skin cancer.

Health experts say the study will help persuade people to protect themselves from skin cancer, and dismiss the myth that sunscreen prevents vitamin D sufficiency

Concerns have been raised that sun protection methods, including the use of sunscreen, may be contributing to vitamin D deficiency.

Now, three separate studies published by experts from London and Australia in the British Journal of Dermatology have concluded that use of sunscreen does not impact on vitamin D status in the majority of people.

Lead author of the first study Professor Antony Young, of King’s College London, said: ‘Sunlight is the main source of vitamin D.

‘Sunscreens can prevent sunburn and skin cancer, but there has been a lot of uncertainty about the effects of sunscreens on Vitamin D.

‘Our study, during a week of perfect weather in Tenerife, showed that sunscreens, even when used optimally to prevent sunburn, allowed excellent vitamin D synthesis.’

In the first study, conducted by researchers from King’s College London, participants were split into four groups.

The participants, apart from those in the control group, then went on a week-long holiday to an area with a very high UV index.

Twenty people received a broad spectrum sunscreen with a Sun Protection Factor (SPF) of 15, offering UVB protection and high UVA protection.

HOW MUCH VITAMIN D IS SAFE TO TAKE?

Some groups of the population are at greater risk of not getting enough vitamin D. Everyone over the age of five years is advised to consider taking a daily supplement containing 10 micrograms (400 IU) of vitamin D, but most people will get enough in the summer.

The amount of vitamin D contained in supplements is sometimes expressed in international units (IU), where 40 IU is equal to 1 microgram (1µg) of vitamin D.

If you choose to take vitamin D supplements, 400 IU a day will be enough for most people.

People who take supplements are advised not to take more than 4000 IU of vitamin D a day, as it could be harmful (this is equal to 100 micrograms or 0.1 milligrams).

This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17.

Children aged 1 to 10 shouldn’t have more than 2000 IU a day. Babies under 12 months shouldn’t have more than 1000 IU a day.

Some people have medical conditions that mean they may not be able to take as much vitamin D safely.

There’s no risk of your body making too much vitamin D from sun exposure, but always remember to cover up or protect your skin before the time it takes you to start turning red or burn.

Source: NHS

A further 20 people received a non-broad spectrum sunscreen, also SPF15 but with low UVA protection.

The two groups were told how to use their sunscreens correctly, so as to achieve the labelled SPF.

In contrast, 22 people used their own sunscreen with no instructions on how to apply it, and 17 people formed a control group who remained in Poland.

Blood samples were taken from participants 24 hours before and 24 to 48 hours after the holiday.

SPF 15 sunscreens applied at sufficient thickness to inhibit sunburn allowed a ‘highly significant’ improvement of vitamin D levels.

The broad spectrum sunscreen also enabled higher vitamin D synthesis than a low UVA protective sunscreen.

The researchers said this was possibly because the former, due to its composition, transmits more a little more UVB than the latter.

The people who used their own sunscreens, also had significant vitamin D synthesis, but they all had sunburn.

The researchers said that was almost certainly because they did not use their sunscreens correctly.

The second study was led by researchers from the QIMR Berghofer Medical Research Institute in Australia and the Australian National University.

They reviewed all published experimental studies, field trials, and observational studies published between 1970 and 2017, totalling 75 articles.

They found that, while the experimental studies – using artificial light sources in a lab setting – support the theoretical risk that sunscreen use may affect Vitamin D,

They said the weight of evidence from field trials and observational studies – taking place in real-life situations involving natural sunlight – suggests that the risk is low.

However, experimental studies, using artificial light sources in a lab setting, support the theoretical risk that sunscreen use may affect vitamin D.

A further review which presents the findings of an international panel of 13 experts also concluded that sunscreen use is unlikely to affect vitamin D production and that UVA protection does not affect vitamin D synthesis.

Holly Barber, of the British Association of Dermatologists, said: ‘The ability to achieve adequate protection from the sun to avoid sunburn, a risk factor of skin cancer, whilst not impacting vitamin D production is really encouraging.

‘The risk of vitamin D deficiency from sunscreen has been found to be low, and therefore is unlikely to outweigh the benefits of sunscreen for skin cancer prevention.’

She added: ‘Further research is required on SPF 30 and higher sunscreen, as this is what we recommend people use for optimal protection in real-life situations.

‘People with dark skin types are at a higher risk of Vitamin D deficiency, and lower risk of skin cancer, so further research is also required to see how these findings translate to people with dark skin types.’

HOW WAS THE RESEARCH CARRIED OUT?