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Your body needs sunshine for health - even Australia agrees


Why your skin needs to see the sun WITHOUT sunscreen every day: Experts have radically changed their rules for UV exposure and the risk of skin cancer - this is how it affects you

By JINAN HARB FOR THE DAILY MAIL

As summer approaches and the sun comes out, we all know the drill: slather on the sunscreen and seek shade at the hottest times of the day to prevent sunburn, wrinkles and, worse, skin cancer. Or is the drill set to change?

For there seems to be a shift in experts’ views on sun exposure as they acknowledge there are ­benefits to it: because as well as helping our skin make vitamin D, we also now know it improves our mental health, is good for our eyesight and helps regulate our body clocks, which in turn affects all our body functions. It may even directly lower our blood pressure.

For this reason, leading experts now think we should all be getting short bursts of sun exposure every day — without sunscreen.

The latest consensus among scientists is that a lack of sun causes more deaths than exposure itself

‘For too long, dermatologists have been fixated on skin cancer, meaning we have not properly ­considered that sunlight has health benefits for us all,’ says ­Richard Weller, a professor of medical ­dermatology at Edinburgh University and an ­honorary consultant dermatologist at NHS Lothian.

What’s more, the new thinking is that sun-safety advice should be tailored according to skin tone — in particular, those with darker skin are thought to benefit the most from sun exposure, leading some experts to suggest they don’t apply as much sunscreen. As Dr Derrick Phillips, a consultant ­dermatologist in London and spokesperson for the British Skin Foundation, explains: ‘In the past, our sun safety messaging has combined into one: everyone should cover up and everyone should wear high-factor ­sunscreen. But it’s far more complex.

‘For instance, the relationship between UV ­exposure and skin cancer isn’t as strong for people with black or brown skin tones. They can still get skin cancers, but these cases aren’t usually linked to sun exposure and often occur in non-sun-exposed areas. But they will still be told that they need to apply SPF — when in fact that wouldn’t have ­protected them from these cancers at all.’

NEW ADVICE FOR PEOPLE WITH DARKER SKIN

The new thinking about skin tone is a major ­development from scientists in Australia. After an analysis by the QIMR Berghofer ­Medical Research Institute in Brisbane, they issued new guidelines — endorsed by Cancer Council Australia, among other leading bodies — that acknowledge sun exposure can be both harmful and beneficial to health, and that the risks differ in different groups.

As Anne Cust, a professor of cancer epidemiology at the ­University of Sydney and chair of the Cancer Council’s National Skin Cancer Committee, told Good Health: ‘This is a shift in thinking, acknowledging ­diversity within the population.

‘We are trying to tailor the advice, acknowledging that not everyone has the same risk of skin cancer and to balance the benefits and risks from sun exposure.

‘The main difference is that ­people with dark skin are no longer being told that they need routine sun protection.

‘The evidence from people with darker skin types suggests that the benefits they get from sun exposure outweigh the risks. They have a low risk of skin cancer, for instance, but a high risk of ­vitamin D deficiency. So unless they are outside for extended periods, they don’t need to cover up.

‘Meanwhile, for anyone with fair or olive skin, the risks of sun ­exposure in terms of skin cancer still outweigh the benefits of ­vitamin D — so sun protection is still advised when the UV index is three or more.’ The UV index is a measure of the burning ability of the sun; it’s often displayed on weather apps, or uvindex.app.

(The situation is more nuanced for preventing wrinkles and ­pigmentation; more on that later.)

The Australian guidelines split adults into three broad groups: people with very pale skin (or olive with a family history of skin ­cancer) are deemed high risk for skin cancer; those with dark skin who are at low risk of skin cancer and higher risk of vitamin D ­deficiency; and between them are those with olive or pale brown skin, whose risk is intermediate, but risk/benefit is less straightforward.

The evidence from people with darker skin types suggests that the benefits they get from sun exposure outweigh the risks

This group is advised to spend time outdoors but without ­burning, or to apply sunscreen if ­outside for longer periods. Australia is seen as an authority in sun safety advice because of its high levels of UV year-round and high rates of skin cancer — and its years of research.

‘Our rates of skin cancer are the highest in the world, almost ­double the rates in western Europe,’ says Professor Cust. ‘Two-thirds of ­Australians get skin cancer.’

The most common types are basal cell carcinoma (which develop from cells in the deepest part of the outer layer of the skin) and squamous cell (generally faster growing and beginning in the epidermis, the most ­superficial skin layer). Both are caused by UV radiation, but don’t ­usually spread — unlike melanoma, the most deadly type of skin cancer.

The high rates in ­Australia are due to the climate, says Professor Cust: ‘In summertime our UV index can reach 12 or higher — for ­comparison, in the Mediterranean it gets to 8/9; and in the UK it doesn’t tend to get above 6-8.’

‘Australia is in a unique position because of its understanding of UV ­exposure — it is a world leader,’ says Dr Phillips. This is why experts are taking note of the change in their sun safety guidance. Professor Weller adds: ‘It is most interesting that this advice has come from the Australians — a mainly white population in a high-UV environment, so at ­highest risk from UV. Even they are now acknowledging that sunlight has health benefits.

‘It means that in the UK, where we have much less sunlight, we need to focus on ways we can maximise the benefits.’

Many factors led to the updated ­guidelines, says Professor Cust. ‘One was the growing research into ­potential benefits of sun ­exposure ­additional to vitamin D.

‘There was also new data modelling which provided more clarity on how much sun exposure is needed to maintain vitamin D ­levels without skin burning.’

This involved a ­complicated calculation based on the time of year, time of day, location, as well as the angle of the sun and ozone level, and on the assumption that 35 per cent of the body was exposed (i.e. as if wearing a short-sleeved shirt and shorts/skirt above the knee).

‘The truth is most people don’t need a lot,’ says Professor Cust. ‘In most places across Australia in summer, lighter skin types only need a few minutes’ sun exposure a day to make enough vitamin D; in winter, you may need an hour in places further from the equator.’

(She wears a hat and sunglasses when outside in all seasons and keeps sunscreen on the kitchen counter to apply every morning, reapplying as recommended.)

‘The new Australian guidelines are excellent and well considered,’ says Professor Weller, reflecting the consensus of the UK experts Good Health spoke to.

‘Previously we only considered the harm that sunlight can do and thought all skin colours respond in the same way — but both of these assumptions are incorrect.’

Our response to UV is ­determined by melanin, a protein that gives skin its colour — the darker the skin, the more melanin. When light skin begins to tan, it’s a sign that it is ­producing more melanin to protect itself; a sign of skin damage. So could the UK sun protection advice soon replicate Australia’s?

‘In fact, the UK National Institute for Health and Care Research [the research arm of the NHS] is currently reviewing our sunlight guidelines — and I would be amazed if they didn’t make the same sensible changes,’ says ­Professor Weller, adding that the report should be issued in May.

Dr Phillips adds: ‘This is a sensible, nuanced approach to a complex problem. The advice up until now has been broad-brush and aimed at fair-skinned people, leaving many with darker skin tones confused. The truth is, they don’t have the same risk factors as fair-skinned people, and so the advice is very welcome. It may take time, but we need a similar approach.’

Dr Justine Hextall, a consultant dermatologist at Tarrant Street Clinic in Arundel, West Sussex, says ‘the advice is overdue’, pointing to earlier research such as a 2009 study of melanoma patients which showed ‘low vitamin D levels [at diagnosis] were associated with poor prognosis . . . and an increased risk of recurrence’ (the Journal of Clinical Oncology).

Perhaps surprising to learn is that the same UVB rays from the sun that are linked to skin cancer, including melanoma, are also what enables our skin to make vitamin D. But 24 per cent of men and 22 per cent of women are deficient, according to the National Diet and Nutritional Survey, reported BMJ Open in 2021. People from black and Asian ethnic groups are most at risk, it concluded.

That’s partly because darker skin contains more melanin, which absorbs UVB and blocks the ­substance in the skin that kick-starts vitamin D production. As a result, dark-skinned people tend to require more UVB exposure than light-skinned people to ­generate the same amount of ­vitamin D.

The problem is worse in the northern hemisphere as vitamin D production depends on the sun being high in the sky — here, in summer, or at midday — because otherwise the atmosphere filters out much of the UVB. That’s why even light-skinned people fail to produce much ­vitamin D between November and March in higher latitudes, so the UK advice is that everyone take a daily vitamin D supplement in autumn and winter.

A LACK OF SUN CAUSES MORE DEATHS

‘The general advice from ­dermatologists to date has been wrong — a lack of sun exposure causes more deaths than sun exposure itself,’ says Professor Weller.

He points to a 2014 study in the Journal of Internal Medicine which analysed data from more than 29,000 women in Sweden and concluded that avoiding sunlight led to higher overall death rates.

‘Mortality rate among avoiders of sun exposure was approximately two-fold higher compared with the highest sun exposure group,’ researchers concluded.

Professor Weller says our ­tendency to get our sunlight and vitamin D via two weeks in the Med over the summer holiday is harmful and it’s what burns us. ‘We should instead be aiming for a little unprotected sun exposure every day for the benefits with much less risk,’ he says.

For those with light skin tones, aim for short bursts out in the sun between 11am and 3pm — with bare arms or legs — every day.

The key is to stay outside long enough without going red — so the exposure is below the threshold for sunburn, says Dr Hextall.

Research by Manchester University suggests that ten to 15 minutes’ sun exposure daily during the spring and summer should provide adequate vitamin D to avoid a deficiency all year round.

For people with darker skins, around 25 to 40 minutes under the same conditions will avoid summertime deficiency, and vitamin D supplements should be considered during the winter months.

Antony Young, an emeritus ­professor of experimental photobiology at King’s College London, adds: ‘My research has concluded that the dose of sunlight you need on a frequent basis in summer for this benefit is much less [possibly around a tenth] than the dose needed for sunburn.’

However, Dr Hextall notes it’s unlikely you’ll get quite enough exposure in the UK to build huge stores (vitamin D is stored in the liver), so most people should still consider taking a supplement in the winter months. ‘Supplements are good, but the benefits of UV exposure are ­superior,’ she says. Indeed, ­studies have suggested we don’t absorb the vitamin as well in supplement form, and may not always get the dose stated.

UV EXPOSURE MAY CUT BLOOD PRESSURE

IN 2016 a review into the risks and benefits of sun exposure warned of insufficient sun exposure as ‘an emerging public health problem’.

The researchers from the ­University of South Carolina ­concluded: ‘The risks of ­inadequate non-burning sun exposure include increased risks of all-cause ­mortality, colorectal cancer, breast ­cancer, non-Hodgkin lymphoma, prostate cancer, pancreatic cancer, hypertension, cardiovascular ­disease, metabolic syndrome, type 2 ­diabetes, obesity, Alzheimer’s, multiple sclerosis, type 1 diabetes, rheumatoid arthritis, ­psoriasis, non-alcoholic fatty liver disease, statin intolerance, ­macular ­degeneration and myopia.’

(Some of these were linked to vitamin D levels, but other effects were via other mechanisms.)

Dr Hextall says: ‘Some exposure to UV is good for us — it’s thought to be associated with a sense of wellbeing, for instance, and influences cells at the back of the eyes that affect our circadian rhythm [or body clock], which influences everything from heart and brain health to sleep quality.’

Professor Weller’s research has focused on how sunlight reduces blood pressure — and, in turn, cuts the risk of heart attack and stroke, which are the biggest killers of all diseases. ‘Sunlight exposure releases nitric oxide from skin cells — this goes into the circulation and relaxes blood vessel walls and lowers blood pressure,’ he says.

‘This is via an independent mechanism to vitamin D — so while taking a supplement helps replenish levels of this vitamin, it won’t reproduce the multitude of other benefits of sunlight exposure such as on blood pressure.’

He says the incidence of heart disease in those from black ethnic groups — known to be higher than others — may partly be caused by a lack of sun exposure.

‘Their skin is designed for a high-UV environment, so in low UV it suffers,’ he says. ‘We’ve published research that shows those with darker skins don’t get the healthy fall in blood pressure following sun exposure that a lighter-skin person does. They need more sun exposure for the same benefit.

‘The main causes of death in darker-skinned people are diseases of high blood pressure — our data strongly suggests ­sunlight reduces that. And this process can be blocked by sunscreen.’ Professor Young says this view is still quite controversial.

‘Richard has a good point, but not everyone in the field shares that view. The research into ­lowering blood pressure has mainly been demonstrated in a laboratory and supported by ­epidemiological studies [which analyse patterns across populations].

‘But we don’t yet know, for example, the dose of sunlight that lowers blood ­pressure. Nevertheless, I’ve shifted my view over the past few years towards thinking that some sun exposure is more beneficial than previously thought. At the start of the pandemic I did my best to boost my vitamin D levels as it’s important for immunity.’

The results weren’t quite as he expected. ‘For the first time in decades I deliberately exposed myself to the sun — I sat out on my balcony, mid-morning, not wearing too much for 30 minutes or so. To my surprise when I took my blood pressure before and after sitting outside, it often fell.

‘Since then, I try to keep my ­vitamin D levels high naturally, by regular short (ten to 15 minutes’ worth) intentional exposure to sun. I will be 76 next birthday.’

Meanwhile, Dr Hextall wears SPF50 on her face all year round and a vitamin C serum ‘to ­mitigate the damage of UV exposure’.

‘However, I do aim to get at least ten minutes of sun exposure daily to my arms, neck and chest without SPF to boost vitamin D.’

DOES SUNSCREEN BLOCK VITAMIN D?

So does wearing SPF block the UV needed to make vitamin D?

‘In laboratory studies there’s some evidence that sunscreen might reduce vitamin D production,’ says Professor Cust.

‘But in real-life studies, it doesn’t — probably because we don’t apply a thick enough layer.’

The most common types of skin cancer are basal cell carcinoma (pictured, which develop from cells in the deepest part of the outer layer of the skin) and squamous cell (generally faster growing and beginning in the epidermis, the most ­superficial skin layer)

The most common types of skin cancer are basal cell carcinoma (pictured, which develop from cells in the deepest part of the outer layer of the skin) and squamous cell (generally faster growing and beginning in the epidermis, the most ­superficial skin layer)

Yet even so, is it time for some people to consider cutting back on routine sunscreen use? ‘It depends on what you are wearing sunscreen for,’ says Professor Weller. He says it’s a ‘dilemma he faces’, as ‘wearing SPF would protect him from burning and cancer, but the problem with existing sunscreens is they block many of the benefits. The bottom line is, I avoid getting burnt.

‘Sunscreen stops ­wrinkles and sunburn. But it takes about six times as much sunlight for people with darker skin to burn compared to someone with [fair] white skin.’

For skin tones that are between these, it is more complicated but, in general, the darker skin is, the less protection is needed.

Dr Phillips argues: ‘There’s still a good reason to wear sunscreen for pigmentation, where sun ­damage causes darker spots, for instance; to protect against sunburn; and for its anti-ageing benefits.’ (He uses vitamin C and sunscreen every day to prevent pigmentation and ­premature ageing.)

Dr Hextall adds: ‘In order to ­balance this risk with sufficient vitamin D ­production, people with darker skin may protect their face with sunscreen but expose other body parts to the sun, such as the arms and legs.’

The point is we must move away from broad-brush statements, says Dr ­Phillips. ‘We can’t say that ­people with darker skins should never wear sunscreen because there is still a risk of sunburn — and sunburn is a critical step in the sequence that leads to skin damage and, possibly, skin cancer. The likelihood of burning is lower in darker skins, but it’s not zero.’


Vitamin D Life – No – 10 minutes per day of sun-UVB is NOT enough contains


Vitamin D Life – UV and D contains

374 items in UV category   see also

Vitamin D from low-cost UVB lamps has the following update

Founder of Vitamin D Life bought a GE lamp fixture Jan 2019 and used UVB bulk from previous Light Year 2 fixture
Bulb is said to last 4,000 hours, so UVB bulb would cost 1 cent per hour
GE 16466 Basic 18 Inch Fluorescent Under Cabinet Amazon $13
G15T8E 15W Germicidal UV-B Fluorescent Lamp $25 including USPS to Seattle
OR    Ushio BC3286 USHIO G15T8E 14.7W Midrange UV Fluorescent Lamp Amazon $38
Put the bulb and fixture at top of a ladder (near the ceiling) and measured UVB at chest level 7 feet from bulb

ReflectorDirect
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Similar reading with a direct view of the bulb and with reflector made with aluminim foil placed between the ceiling and the wall
8 IU per minute: UVB Meter calibrated for 20% of skin area for a 20 year-old (approximately face and hands)
500 IU per hour - 20 year-old
5,000 IU per 10-hour- 20-year-old
1200 IU per 10 hours for a senior (assumes 1/4 as much UVB created Vitamin D)
It appears that the celing paint, by itself, does not reflect any UVB
As expected, the plastic bulb cover on the GE fixture is opaque to UVB
UVB intensity at 2 feet across countertop
Countertop might reflect, so reading would be lower if no countertop
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Intensity 85 @ 2 feet with reflector
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5,300 IU per hour - 20-year-old, 1300 IU senior
Warning: Start with very short durations
Try one day at ~3 minutes, and see if get UV burn/pinking the following day
Double the time each day,until get slight burn/pinking the following day, then reduce the duration (perhaps by 1/3)
Note: Burning is more likely if:

  1. Low blood level of Vitamin D
  2. Same portion of skin had had UVB dose in past few days

Closeup photo of Al foil reflector
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41+ Vitamin D Life "Noontime Sun" OR UV pages have CANCER in the title

This list is automatically updated

Items found: 41
Title Modified
23 Cancers if little sun, 12 of which have been associated with low vitamin D – March 2022 02 Jul, 2023
Vitamin D from the sun reduces the risk of internal cancers, but increases some skin cancers – Nov 2021 05 Feb, 2023
Gastric Cancer, Vitamin D, VDR, UV - many studies 10 Nov, 2022
Less Solar Radiation was associated with more Cancer - 1941 01 Aug, 2022
Most sunscreens actually increase the growth of skin cancer - May 2010 26 Apr, 2021
Some cancer rates are reduced when live at high altitude, but other cancers increase after a few generations – March 2021 27 Mar, 2021
Book: Sunlight, UV, Vitamin D and Receptor, Skin and other Cancers - Dec 2020 09 Dec, 2020
Breast Cancer risk reduced 17 percent by 1 hour of daily summer sun – meta-analysis Jan 2020 07 Jan, 2020
High levels of Vitamin D and low rates of skin cancer among commercial fishermen – July 2019 01 Aug, 2019
Brain cancer in 175 countries related to low UVB and low vitamin D – Oct 2010 03 Oct, 2018
Sunscreen use is no longer associated with reduced skin cancer – meta-analysis April 2018 10 Jul, 2018
UVA causes skin cancer, perhaps UVB (Vitamin D) prevents skin cancer – Jan 2017 27 Jan, 2017
Skin cancer (in mice) due to UV was prevented by vitamin D (active, topical) – June 2016 07 Jan, 2017
Getting little UV is associated with 15 types of Cancer – Jan 2012 26 Aug, 2016
Sunscreen used daily vs discretionary: no difference in skin cancer rate – RCT 2016 06 Aug, 2016
A review of the evidence regarding the solar ultraviolet-B-vitamin D-cancer hypothesis - Oct 2012 08 Jan, 2016
Cancer - far less for outdoor workers 11 Jun, 2015
Vitamin D from the sun while minimizing skin cancer - Interview by Dr. Mercolla of Dr. Cannell - Nov 2014 17 Nov, 2014
Fewer heart attacks, hip fractures and deaths if more skin cancer – Sept 2013 09 Nov, 2014
Elite NZ Outdoor athletes fear skin cancer 10X more than fear low vitamin D – Sept 2014 18 Sep, 2014
Many other anti-cancer photoproducts generated on the skin in addition to vitamin D – Jan 2014 19 Aug, 2014
Less intestinal cancer in mice if add vitamin D, but even less with ultraviolet light – June 2014 05 Jun, 2014
Cancer Council of Australia recommends 30 minutes of daily sunshine – June 2014 04 Jun, 2014
Walking an hour a day (more vitamin D) decreased chance of breast cancer by 14 percent – Oct 2013 20 Mar, 2014
Excessive sun increases cancer all around the body – July 2011 16 Mar, 2014
Cancer incidence in 87 countries is related to food, smoking, alcohol, GDP, and UVB - Jan 2014 08 Jan, 2014
Decreased risk of non-melanoma skin cancer by working outdoors in Europe – April 2013 22 Dec, 2013
Too much UVB: skin cancer, too little UVB: other cancers due to low vitamin D – April 2012 18 Nov, 2013
4 uses of tanning beds per year did not reduce rate of internal cancers – Oct 2013 16 Oct, 2013
Solar UVB reduces Cancer Risk – Grant, Jan 2013 02 Oct, 2013
Eye cancer and UV – Review of controversy – Sept 2013 09 Sep, 2013
Less UV: 2X more breast cancer – June 2011 08 Jul, 2013
More UVB is associated with less cancer – study of 450,000 people – April 2012 13 Apr, 2013
Some childhood cancer 30% less likely in parts of California with more UVB – April 2013 13 Apr, 2013
Texas company claimed tanning beds prevent cancer – had to pay 142,000 dollar fine – March 2013 13 Mar, 2013
China has documented that less UV results in more cancer – June 2010 07 Jan, 2013
The sun appears better at reducing incidence of some cancers than vitamin D – Dec 2012 17 Dec, 2012
Vitamin D protects mouse from skin cancer – Sept 2012 29 Nov, 2012
UVB and vitamin D inversely associated with pancreatic cancer April 2010 31 Oct, 2012
Lack of solar UVB in US is associated with some Cancers - 2006 28 Dec, 2011
Some cancer due to low UV – Grant – April 2010 13 Oct, 2011