Adequate sun exposure is essential for optimal health

George Jelinek

Professor of Emergency Medicine

University of Western Australia

Overview

• The controversy

• Background– Sunlight and UV light– Vitamin D

• The evidence

• Conclusions and recommendations

The messagesA lot of data but simple messages:

• Vitamin D deficiency due to inadequate sunshine is an epidemic in the West– Population calcium supplementation has

resulted and is unnecessary

• Avoiding the sun makes us sick– Most of us need more sunlight to be really

well

The controversy

• Growing debate about public health messages regarding sun avoidance*

• Growing burden of disease related to inadequate vitamin D– Without sun, there would be no life on earth:

why continue regarding sunlight as poison?* Lucas RM, Ponsonby AL. Ultraviolet radiation and health: friend and foe.

Med J Aust 2002; 177:594-8

Ness AR, Frankel SJ, Gunnell DJ, et al. Are we really dying for a tan? BMJ 1999; 319:114-16

Changing mainstream opinion• ‘The paradox of Vitamin D deficiency emerging as a

public health issue in sunny Australia’*

• ‘It is no longer acceptable to assume that all people in Australia receive adequate Vitamin D from casual sunlight exposure’+

• ‘Vitamin D deficiency is now recognised as an epidemic in the United States’^

* Ebeling PR. Megadose therapy for vitamin D deficiency. Treating the paradox of an important emerging public health problem. Med J Aust 2005;183:4-5

+ Nowson CA, Diamond TH, Pasco JA, et al. Vitamin D in Australia. Aust Fam Phys 2004;33:133-138

^ Holick MF. The vitamin D epidemic and its health consequences. J Nutr 2005;135:2739S-48S

Background

• Sunlight composition– Mixture of infrared, visible and ultraviolet– Ultraviolet comprises UVA, UVB, UVC

• UVB – Only about 5%– Acts on skin to form vitamin D

Formation of vitamin D• Amount of vitamin D formed depends on:

– Area of skin exposed to sunlight– Length of time exposed

• Upper limit of 10 000-15 000 IU after which no more produced– This takes all over exposure for 10-15mins at

midday on a spring day– Skin makes about 1 000 IU a minute for 15 mins

then no more

Vitamin D

• Main action is to increase absorption of calcium from gut and deposition in bone

• More recently found that vitamin D has profound effects on immune system

• Other effects on muscle, balance, mood

• Impossible to get adequate amounts from diet alone

Effects of vitamin D deficiency

• Calcium effects– Ricketts, osteoporosis, fractures

• Hypertension, depression, weakness, falls#• Immune effects

– Increased incidence and severity of autoimmune diseases and cancers*

# Bischoff HA, Stahelin HB, Dick W, et al. Effects of vitamin D and calcium supplementation on falls: a randomised controlled trial. J Bone Miner Res 2003;18:343-51

* Ponsonby AL, McMichael A, van der Mei I. Ultraviolet radiation and autoimmune disease: insights from epidemiological research. Toxicology 2002; 181-182:71-8

Diseases from low vitamin D• Cancers*

– Digestive tract cancers• Esophageal, gastric, colon, rectal

– Breast and reproductive system cancers• Breast, cervical, endometrial, ovarian, vulva

– Urogenital cancers• Bladder, kidney, prostate, renal, testis

– Other cancers• Gallbladder, laryngeal, pancreatic, Hodgkin’s

lymphoma, non Hodgkin’s lymphoma

* Grant WB. Ecologic studies of solar UV-B radiation and cancer mortality rates. Recent Results Cancer Res 2003; 164:371-7

US UV exposure

Breast cancer

Colon cancer

Diseases from low vitamin D• Autoimmune disorders

– Multiple sclerosis, rheumatoid arthritis, insulin dependent diabetes, SLE

• Bone disorders– Ricketts, osteoporosis, osteomalacia, fractures, poor

fracture healing• Mood disorders

– Depression, seasonal affective disorder (SAD)• General health

– High BP, CHD#, irritable bowel, Crohn’s disease, falls, muscle weakness

# Grimes D., Hindle E., and Dyer T., Sunlight cholesterol and coronary heart disease. QJM 1996; 89;579-589

MS prevalence WW2 veterans at entry into armed forces by latitudeMultiple Sclerosis Prevalence for U.S. WWII, KC Veterans

at Time of Entery into the Armed Forces vs. Latitude

Latitude (degrees N)

25 30 35 40 45 50

MS

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(rel

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its)

20

40

60

80

100

120

140

160

180

200

220

Average annual ultraviolet radiation (kJ/m per day), 1979-92

Age

-sta

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d M

S p

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2 3 4 5

0

10

20

30

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Age-standardised MS prevalence in relationto ambient ultraviolet radiation, Australia,

1981

6

Fitted polynomial curve: r = - 0.91

Van der Mei et al, Neuroepidemio logy 2001

Seasonal variation in Vitamin D levels versus no of new MS lesions

Current vitamin D ranges

• Current mod/severe deficiency: <25nmol/L

• Current mild deficiency: <50nmol/L

• Lots of evidence that this range too low*

• Even at these levels, large proportion of population has low levels

* Vieth R. Why the optimal requirement for Vitamin D(3) is probably much higher than what is officially recommended for adults. J Steroid Biochem Mol Biol 2004; 89-90:575-9

Vitamin D deficiency

• In hostels and nursing homes– 80% of women– 70% of men*

• In Geelong women– 30% in summer– 43% in winter#

* Flicker L, Mead K, MacInnis RJ, et al. Serum vitamin D and falls in older women living in residential care in Australia. J Am Geriatr Soc 2003;51:1533-38

# Pasco JA, Henry MJ, Nicholson GC, et al. Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight. Med J Aust. 2001;175:401-5

Target blood range

• Check levels in autumn when level lowest– Aim for at least: 70nmol/L if well

100-140nmol/L if sick– Probably up to 200nmol/L really optimal*– Evidence that 135-225nmol/L normal in sunny

countries where these diseases rare* Grant WB,Holick MF. Benefits and requirements of Vitamin D for optimal

health: a review. Altern Med Rev 2005; 10:94-111

Current vitamin D recommendations

• RDA now 200IU to prevent deficiency– Equivalent to about 6 seconds all over sun in

Perth summer at midday!

• Where these diseases uncommon blood levels at least 100-140nmol/L– 4 000IU/day gives level of 100nmol/L– 10 000IU/day gives level of 140nmol/L

Is Vitamin D toxic?

• Current ‘LOAEL’ is 2 000IU per day– 10 000IU per day perfectly safe*– Only published toxicity is from >40 000IU/day

• Potential toxicity relates to high calcium– Currently much work on vitamin D analogues

to get immune effect without calcium effects– Flawed thinking: nature provides the balance

* Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. Am J Clin Nutr 1999; 69:842-56

Benefits of high normal vitamin D levels

• Not only prevents ricketts, osteomalacia, osteoporosis, autoimmune diseases, cancer, hypertension, depression*

• Prevents complications of these diseases, such as osteoporosis from inactivity, falls (49% drop), fractures, muscle weakness#

• Eliminates the need for Ca supplements: population Ca supplementation unnecessary

* Deluca HF, Cantorna MT. Vitamin D: its role and uses in immunology. Faseb J 2001; 15:2579-85

Zittermann A. Vitamin D in preventive medicine: are we ignoring the evidence? Br J Nutr 2003; 89:552-572

# VanAmerongen BM, Dijkstra CD, Lips P, Polman CH. Multiple sclerosis and vitamin D: an update. Eur J Clin Nutr 2004

How to get adequate vitamin D

• Diet alone not enough

• Simplest and cheapest is adequate sunlight

• Probably also helpful in other ways besides vitamin D (melatonin, etc)

• Supplements

Recommendations: sunlight

• 10-15mins sunlight all over (in speedos)

• 3-5 times a week

• More in winter, less in summer

• Get it while exercising if too cold– Blocked by glass– Passes through water

Risks of adequate sunlight

• Probably none!

• Risks are from excessive sunlight– Various skin cancers– But, for every melanoma prevented by sun

avoidance we incur about 6.6 internal cancers*– Adequate Vit D probably prevents melanoma#

* Grant WB. Ecologic studies of solar UV-B radiation and cancer mortality rates. Recent Results Cancer Res 2003; 164:371-7

# Garland FC, White MR, Garland CF, Shaw E, Gorham ED. Occupational sunlight exposure and melanoma in the U.S. Navy. Arch Environ Health 1990; 45:261-7

bom.gov.au

May 2005 ANZ osteoporosis recommendations for sun exposure

• Melbourne summer: ‘6-8min of sun at 10am or 2pm on hands, face and arms’*

• Melbourne winter: ‘25mins of sun at midday on hands, face and arms’*– Very similar to mine except only 15% of body

exposed: 6-7 times the dose with mine for optimal effect: clearly considered safe exposure

* ANZ Bone and Mineral Society, Endocrine Society of Australia and Osteoporosis Australia. Vitamin D and adult bone health in Australia and New Zealand: a position statement. Med J Aust 2005;182:281-5

Recommendations: supplements

• 4 000IU per day if no sun• Up to 10 000IU per day• Single megadose if levels low is very safe

– Up to half a million units if severe• Single dose of 600 000IU raised levels to 73nmol/L

for people with levels <12.5nmol/L*

* Diamond TH, Ho KW, Rohl PG, Meerkin M. Annual IM injection of a megadose of cholecalciferol for treatment of vitamin D deficiency. Med J Aust 2005;183:10-12

Getting the supplements

• Vitamin D3 unavailable in Australia

• Don’t try to get it from cod liver oil (vitamin A toxicity)

• OstelinR 1 000IU available on prescription but vitamin D2 (synthetic), doesn’t work as well as D3

• Try www.healthau.com for 5000IU capsule

Final recommendation

Enjoy your time in the sun!