ultraviolet light man’s best friend dr. d. czarnecki md mbbs

ULTRAVIOLET LIGHTULTRAVIOLET LIGHTMan’s best friendMan’s best friend

Dr. D. Czarnecki MD MBBSDr. D. Czarnecki MD MBBS

Ultraviolet lightUltraviolet light

• Sunlight has many beneficial effects on men and it has been Sunlight has many beneficial effects on men and it has been known for a long time that sunlight is good for you – even though known for a long time that sunlight is good for you – even though exactly what sunlight did was unknown until recentlyexactly what sunlight did was unknown until recently

• 1385 BC - Echnaton (Egypt) praised sunlight1385 BC - Echnaton (Egypt) praised sunlight

• Hippocrates noted that sunlight leads to faster healing of Hippocrates noted that sunlight leads to faster healing of fracturesfractures

• 135 AD - Anthyllos (Greece) stated that exposure to sunlight 135 AD - Anthyllos (Greece) stated that exposure to sunlight made bodies stronger and activated brain functionmade bodies stronger and activated brain function

• 2020thth century - it was found that the sun prevents rickets century - it was found that the sun prevents rickets

• Ultraviolet light (UVL) is the part that of the sun’s spectrum that Ultraviolet light (UVL) is the part that of the sun’s spectrum that causes the most benefitcauses the most benefit


• Ultraviolet light (UVL) is the part of the sun’s Ultraviolet light (UVL) is the part of the sun’s spectrum lying between 200 and 400 nmspectrum lying between 200 and 400 nm

• It is divided into three components based on certain It is divided into three components based on certain propertiesproperties

• UVC does not penetrate through ozoneUVC does not penetrate through ozone

• UVB does not penetrate through glass or UVB does not penetrate through glass or sunscreens. It is attenuated by ozonesunscreens. It is attenuated by ozone

• UVA does not penetrate through opaque materialsUVA does not penetrate through opaque materials


200nm 290 320 400nm

UVC UVB UVA

ozone

Glass

sunscreen

opaque material


• UVC is the strongest component – most likely to burnUVC is the strongest component – most likely to burn

• UVB is strong and causes sunburnUVB is strong and causes sunburn• It produces a tanIt produces a tan• It damages DNAIt damages DNA• It causes the skin to produce chemicalsIt causes the skin to produce chemicals

• UVA is weakUVA is weak• It darkens existing pigment but does not produce new pigmentIt darkens existing pigment but does not produce new pigment• It penetrates deeply into the skin – may cause wrinklesIt penetrates deeply into the skin – may cause wrinkles


keratinocytekeratinocyte

CYTOKINES

GROWTH FACTORS

VITAMIN DVITAMIN D

HORMONESHORMONES

The epidermal cells (Keratinocytes)The epidermal cells (Keratinocytes)

are chemical power housesare chemical power houses

Vitamin DVitamin D

• Vitamin D is one of the most important chemicals produced by Vitamin D is one of the most important chemicals produced by the skinthe skin

• 7 dehydrocholesterol is converted into 7 dehydrocholesterol is converted into previtamin Dprevitamin D by UVL by UVL

• Previtamin D moves into the circulation, to the liver where it is Previtamin D moves into the circulation, to the liver where it is converted into converted into 25 hydroxy vitamin D25 hydroxy vitamin D (25 OHD) (25 OHD)

• 25 OHD is transported into the kidneys where it is converted 25 OHD is transported into the kidneys where it is converted into into 1 25 dihydroxy vitamin D1 25 dihydroxy vitamin D (1 25OHD) – the active form (1 25OHD) – the active form

7 dehydrocholesterol7 dehydrocholesterol previtamin Dprevitamin D

LIVERLIVER25OHD325OHD3

1.25OHD31.25OHD3KIDNEYSKIDNEYS

UVBUVB

Ultraviolet light is the most important source of vitamin DUltraviolet light is the most important source of vitamin D

EpidermisEpidermis

1.25OHD31.25OHD3BloodBlood

Vitamin DVitamin D

• Dietary precursors enter the liver to be converted into 25OHDDietary precursors enter the liver to be converted into 25OHD

• People cannot obtain enough vitamin D via their dietsPeople cannot obtain enough vitamin D via their diets

• People cannot produce too much vitamin D from the sunPeople cannot produce too much vitamin D from the sun

• UVL UVLUVL UVL

• 7 dehydrocholesterol previtamin D inert substance7 dehydrocholesterol previtamin D inert substance

Vitamin DVitamin D

• It was only recently discovered that he skin also produces the It was only recently discovered that he skin also produces the active form of vitamin D (1 25 OHD)active form of vitamin D (1 25 OHD)

• UVL UVL

• 7 dehydrocholesterol previtamin D 1 25 OHD7 dehydrocholesterol previtamin D 1 25 OHD

• Many other organs, apart from the kidneys, also produce 1 25 Many other organs, apart from the kidneys, also produce 1 25 OHDOHD

Vitamin DVitamin D

• The current recommendations – vitamin D intakeThe current recommendations – vitamin D intake• <13 yrs – 200 IU (international units)<13 yrs – 200 IU (international units)• 51 – 70 yrs – 400 IU51 – 70 yrs – 400 IU• >70 yrs – 600 IU>70 yrs – 600 IU

• Studies of people who are covered in clothing when Studies of people who are covered in clothing when outside, and studies of submariners, suggest that outside, and studies of submariners, suggest that 1000 IU a day1000 IU a day are needed if people do not get some are needed if people do not get some sun on their skinssun on their skins

Vitamin DVitamin D

• Dietary sources of vitamin DDietary sources of vitamin D

• 1 teaspoon of cod liver oil – 1360 IU1 teaspoon of cod liver oil – 1360 IU• 100 g of salmon – 360 IU100 g of salmon – 360 IU• 1 egg – 20 IU1 egg – 20 IU• 1 cup of fortified milk – 98 IU1 cup of fortified milk – 98 IU• There is little in breast milkThere is little in breast milk

• People cannot obtain enough vitamin D from their People cannot obtain enough vitamin D from their ordinary dietsordinary diets

Vitamin D Vitamin D

• It is needed to It is needed to maintain normal body calciummaintain normal body calcium levels levels• It promotes calcium absorption from the small It promotes calcium absorption from the small

intestineintestine• It promotes re-absorption from the kidneysIt promotes re-absorption from the kidneys

• A fall in serum calcium triggers the parathyroid A fall in serum calcium triggers the parathyroid gland to produce parathyroid hormonegland to produce parathyroid hormone

• The kidneys produce more 1,25 vitamin DThe kidneys produce more 1,25 vitamin D• Bone is resorbedBone is resorbed

Vitamin DVitamin D

• Needed for healthy bonesNeeded for healthy bones• Needed for healthy musclesNeeded for healthy muscles

• Prevents osteoporosis?Prevents osteoporosis?

• Prevents cancersPrevents cancers

• Reduces the incidence of auto-immune diseasesReduces the incidence of auto-immune diseases• Reduces the incidence of multiple sclerosisReduces the incidence of multiple sclerosis• Reduces hypertension and myocardial infarctionReduces hypertension and myocardial infarction• Alleviates depression? Alleviates depression? • Deficiency – causes poor spermatogenesis?Deficiency – causes poor spermatogenesis?

Vitamin D Vitamin D musculoskeletal systemmusculoskeletal system

• Vitamin D deficiency is associated with Vitamin D deficiency is associated with osteomalacia and osteomalacia and increased bone turnoverincreased bone turnover – a – a risk for fracturesrisk for fractures

• Deficiency might be associated with osteoporosisDeficiency might be associated with osteoporosis

• Deficiency – poor muscle co-ordination might be Deficiency – poor muscle co-ordination might be presentpresent

• Deficiency – muscle pain might be present. Deficiency – muscle pain might be present. Deficiency might be the cause of “fibromyalgia” Deficiency might be the cause of “fibromyalgia” in older patientsin older patients

Hip fracturesHip fractures

• Thin bones, and poor muscle co-ordination – a risk for Thin bones, and poor muscle co-ordination – a risk for fracturesfractures

• About 20,000 hip fractures a year in AustraliaAbout 20,000 hip fractures a year in Australia

• 87% are older than 55 years87% are older than 55 years• 6% die – inpatients6% die – inpatients• 15 – 20% die within 12 months15 – 20% die within 12 months• 50% have some disability50% have some disability

• Double blind, placebo controlled studies have found that Double blind, placebo controlled studies have found that vitamin D and calcium reduce falls and reduce the number vitamin D and calcium reduce falls and reduce the number of fractures when falls occurof fractures when falls occur

Vitamin DVitamin DCancerCancer

• The closer to the equator people live, the less risk of The closer to the equator people live, the less risk of internal cancers and dying of cancerinternal cancers and dying of cancer

• Women given vitamin D in Nebraska developed Women given vitamin D in Nebraska developed fewer cancers over 4 years compared to controls – a fewer cancers over 4 years compared to controls – a prospective studyprospective study

• Double blind, placebo controlled studies of calcium Double blind, placebo controlled studies of calcium and vitamin Dand vitamin D

Reduced the risk of colonic adenomasReduced the risk of colonic adenomas

Rats given vitamin D then carcinogens developed Rats given vitamin D then carcinogens developed fewer cancers of the colonfewer cancers of the colon

Calcium and vitamin D reduce the incidence of bowel polypsCalcium and vitamin D reduce the incidence of bowel polyps

Fewer bowel polyps – fewer cancersFewer bowel polyps – fewer cancers


• In tissue culture – vitamin D kills cancer cells In tissue culture – vitamin D kills cancer cells (prostate cancer, melanoma)(prostate cancer, melanoma)

• It has It has anti-proliferativeanti-proliferative effects effects• Blocks the cell cycleBlocks the cell cycle• Promotes the differentiation of cellsPromotes the differentiation of cells

• Induces Induces apoptosisapoptosis

• Boosts the immune responseBoosts the immune response

• Reduces angiogenesisReduces angiogenesis


• Improves the response to chemotherapyImproves the response to chemotherapy

• Improves the response to radiotherapyImproves the response to radiotherapy

• Causes hypercalaemiaCauses hypercalaemia

• Analogues are being developedAnalogues are being developed

• These will have some of the benefits without the These will have some of the benefits without the hypercalaemia side effecthypercalaemia side effect

Vitamin D – death preventionVitamin D – death prevention

• Norway – surgery for CA in winter is more likely to Norway – surgery for CA in winter is more likely to kill you than if it is undertaken in the summerkill you than if it is undertaken in the summer

• Boston – lung CA surgery in the winter is more likely Boston – lung CA surgery in the winter is more likely to result in death than if it is in the summerto result in death than if it is in the summer

• Similar findings with cardiac surgery in the UK – Similar findings with cardiac surgery in the UK – higher death rate in winterhigher death rate in winter

• It may be more than the surgeon’s winter depressionIt may be more than the surgeon’s winter depression

Vitamin D – melanomaVitamin D – melanoma

• The role of sunlight in the genesis of melanoma is The role of sunlight in the genesis of melanoma is still being debated. still being debated. SunburnSunburn is the common finding is the common finding in studies through out the worldin studies through out the world

• Indoor workers have a higher incidence than Indoor workers have a higher incidence than outdoor workers – through out the worldoutdoor workers – through out the world

• Melanoma excised in the summer in Australia - live Melanoma excised in the summer in Australia - live longer (adjusted for age, sex, thickness, site, type) longer (adjusted for age, sex, thickness, site, type) than if a melanoma is excised in the winterthan if a melanoma is excised in the winter

• Melanoma survival is better in regions closer to the Melanoma survival is better in regions closer to the equatorequator

CR of incidence for common cancers CR of incidence for common cancers Men, Australia 2010Men, Australia 2010

CancerCancer QueenslandQueensland TasmaniaTasmania

LungLung 58.758.7 70.370.3

BreastBreast

ColonColon 71.371.3 115.8115.8

ProstateProstate 169.2169.2 203.3203.3

MelanomaMelanoma 82.282.2 63.963.9

ACR of incidence for common cancers ACR of incidence for common cancers Women, Australia 2010Women, Australia 2010


LungLung 37.137.1 47.847.8

BreastBreast 130.2130.2 131.4131.4

ColonColon 59.459.4 90.690.6

ProstateProstate


ACR of mortality for common cancers ACR of mortality for common cancers Men, Australia 2010Men, Australia 2010

CancerCancer Queensland Queensland TasmaniaTasmania

LungLung 45.245.2 61.961.9

BreastBreast

ColonColon 23.223.2 35.535.5

ProstateProstate 28.5 29.629.6


CR of mortality for common cancers CR of mortality for common cancers Women, Australia 2010Women, Australia 2010


LungLung 27.727.7 41.641.6

BreastBreast 21.221.2 27.627.6

ColonColon 21.021.0 31.531.5

ProstateProstate


Vitamin DVitamin DDiabetesDiabetes

• UK children given 2000IU of vitamin D – 80% less UK children given 2000IU of vitamin D – 80% less diabetes than their control groupdiabetes than their control group

• Diabetes-prone mice given 25 OHD – 80% less diabetesDiabetes-prone mice given 25 OHD – 80% less diabetes

• Obesity is associated with lower vitamin DObesity is associated with lower vitamin D – it is a risk – it is a risk factor for diabetesfactor for diabetes

• Insulin resistance is more common in vitamin D Insulin resistance is more common in vitamin D deficient people – can be corrected with supplementsdeficient people – can be corrected with supplements

Sun ExposureSun Exposure

• The sun is good for you in small dosesThe sun is good for you in small doses

• Too much sun exposure damages the skin. It causes Too much sun exposure damages the skin. It causes thinning, wrinkles, brown macules, burst blood thinning, wrinkles, brown macules, burst blood vessels – vessels – an aged appearancean aged appearance

• People have to be educated about People have to be educated about safe sunbathingsafe sunbathing

• The aim is not to get sun burnt. Wear appropriate The aim is not to get sun burnt. Wear appropriate clothes and put sunscreen on exposed skin after a clothes and put sunscreen on exposed skin after a certain period of exposurecertain period of exposure

Too much UVL damages the skin – thin wrinkled, bruisedToo much UVL damages the skin – thin wrinkled, bruised

The skin of his stomach is what his skin should look like. The skin of his stomach is what his skin should look like. Note the differenceNote the difference

The demarcation line is visible. The skin looks aged. Note The demarcation line is visible. The skin looks aged. Note the normal skin in the unexposed sites – this is his agethe normal skin in the unexposed sites – this is his age

How many minutes it takes for untannedHow many minutes it takes for untannedskin to burn at noon, on a clear day.skin to burn at noon, on a clear day.

CityCity January January

JulyJuly

DarwinDarwin 99 1919

BrisbaneBrisbane 1010 5959

SydneySydney 11.511.5 120120

MelbourneMelbourne 12.512.5 210210

HobartHobart 14.314.3 450450

Sun ExposureSun Exposure

• The average white Australian’s tan has an SPF of 3 – The average white Australian’s tan has an SPF of 3 – he can stay outside three times as long as someone he can stay outside three times as long as someone with out a tanwith out a tan

• The average Indian has an SPF of 15 – he will burn The average Indian has an SPF of 15 – he will burn every day in Darwin if he stays outside all dayevery day in Darwin if he stays outside all day

4 months of the year in Melbourne4 months of the year in Melbourne

• Even Blacks burn – Viv Richards will tell you that Even Blacks burn – Viv Richards will tell you that sunburn is just as painful in blacks as whitessunburn is just as painful in blacks as whites

• Some Asians have pale skin - 14% of Koreans have Some Asians have pale skin - 14% of Koreans have light skin– they easily burnlight skin– they easily burn

How many minutes it takes for untannedHow many minutes it takes for untannedand (an average tanned skin) to burnand (an average tanned skin) to burn

CityCity January January

JulyJuly

DarwinDarwin 9 (27)9 (27) 19 (57)19 (57)

BrisbaneBrisbane 10 (30)10 (30) 59 (177)59 (177)

SydneySydney 11.5 (31.5)11.5 (31.5) 120 (360)120 (360)

MelbourneMelbourne 12.5 (37.5)12.5 (37.5) 210 (630)210 (630)

HobartHobart 14.3 (42.9)14.3 (42.9) 450450

SunscreensSunscreens

• Slow down sun damageSlow down sun damage• Prevent new solar keratoses (SKs) – Australia, USA, Prevent new solar keratoses (SKs) – Australia, USA,

EuropeEurope• Prevent new SKs even in renal transplant recipients Prevent new SKs even in renal transplant recipients

– if they are applied every day– if they are applied every day• Prevent SCCs – a Queensland prospective studyPrevent SCCs – a Queensland prospective study• Prevent skin cancer in renal transplant recipients Prevent skin cancer in renal transplant recipients

(German study)(German study)

• Sunscreens prevent vitamin D formationSunscreens prevent vitamin D formation

SunscreensSunscreens

• Some studies suggest that sunscreen use is associated with Some studies suggest that sunscreen use is associated with an increased risk of melanoma an increased risk of melanoma

• These were not always well designed studies.These were not always well designed studies.• Some facts that need to be addressed in future studiesSome facts that need to be addressed in future studies

• People who sunburn easily – more likely to use a sunscreen People who sunburn easily – more likely to use a sunscreen (also more likely to get a melanoma)(also more likely to get a melanoma)

• People may apply a sunscreen when at the beach, but what People may apply a sunscreen when at the beach, but what about the rest of the time? A lot of exposure occurs during about the rest of the time? A lot of exposure occurs during activity e.g. walking aroundactivity e.g. walking around

• Some studies were retrospective therefore biased – people are Some studies were retrospective therefore biased – people are more likely to use a sunscreen after a melanoma was more likely to use a sunscreen after a melanoma was diagnoseddiagnosed

Vitamin D deficiency is largely a cultural problemVitamin D deficiency is largely a cultural problem..

Moslem womenMoslem womenWomen who work in officesWomen who work in officesNursing home patientsNursing home patientsAfrican immigrantsAfrican immigrantsDermatologistsDermatologists

Expose the head and forearms to the sun for 15 Expose the head and forearms to the sun for 15 minutes, five times a week at noonminutes, five times a week at noon

Vitamin DVitamin D

• For adequate levels of vitamin DFor adequate levels of vitamin D

• People need to expose 20% of the body, at noon, forPeople need to expose 20% of the body, at noon, for

10 minutes if they do not tan10 minutes if they do not tan

for 15 minutes if they tanfor 15 minutes if they tan• Three days a week (no sunscreen)Three days a week (no sunscreen)

• After this exposure, cover up or put a sunscreen onAfter this exposure, cover up or put a sunscreen on

Vitamin DVitamin D

• Why not take vitamin D and avoid the sun?Why not take vitamin D and avoid the sun?

• UVL induces the skin to produce many other UVL induces the skin to produce many other chemicals including chemicals including hormoneshormones

• These hormones have many properties such as:These hormones have many properties such as:

producing a tanproducing a tan

anti-inflammatory propertiesanti-inflammatory properties

appetite suppressionappetite suppression

influence lipid metabolisminfluence lipid metabolism

influence moodinfluence mood

HormonesHormones

• Keratinocytes produce a large hormone calledKeratinocytes produce a large hormone called

pro-opiomelanocortinpro-opiomelanocortin

• This enters the circulation and is cleaved into other This enters the circulation and is cleaved into other hormones in different tissueshormones in different tissues

• These hormones have many beneficial effects. The These hormones have many beneficial effects. The endorphins make people feel better and is possibly endorphins make people feel better and is possibly why sunbathing is addictive to somewhy sunbathing is addictive to some

Keratinocyte

UVL

Pro-opiomelanocortinPro-opiomelanocortin

αMSH endorphinsACTH

Ultraviolet LightUltraviolet Light

• Damages the epidermis and dermis (in big Damages the epidermis and dermis (in big doses)doses)

• Suppresses the immune system

• Causes the epidermal cells to produce many Causes the epidermal cells to produce many chemicalschemicals

• Produces a tanProduces a tan• Causes skin cancerCauses skin cancer

Langerhans cells inactiveLangerhans cells inactive

Melanocyte - DNA damage

Keratinocyte - DNA damage, p53 damagedKeratinocyte - DNA damage, p53 damaged

ULTRAVIOLET LIGHTULTRAVIOLET LIGHT

UVL damages DNA, DNA repair enzymes, and causes cutaneous immunosuppression (it damages Langerhans cells)

ultraviolet light man’s best friend dr. d. czarnecki md mbbs

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