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sun for Gawler
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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 message
A lot of data but a simple message:
• 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’+
* 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
Background
• Sunlight composition– Mixture of infrared, visible and ultraviolet– Ultraviolet comprises UVA, UVB, UVC
• UVB – Only about 5%– Blocked by glass, passes through water– 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 to 15 000 IU after which no more produced– This takes all over exposure for 10-15mins at
midday on a UV index 7 day
UV index
• Each point on UV index scale equivalent to 25mW energy per square metre
• So if UV index 14, you need half the time for the same amount of vitamin D as if UV index 7
• UV index in Melbourne about maximum 12 in summer, 1 in winter
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
US UV exposure
Breast cancer
Colon cancer
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
Pre
vale
nce
(rel
ativ
e un
its)
20
40
60
80
100
120
140
160
180
200
220
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
• 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
* Grant WB. Ecologic studies of solar UV-B radiation and cancer mortality rates. Recent Results Cancer Res 2003; 164:371-7
# Grimes D., Hindle E., and Dyer T., Sunlight cholesterol and coronary heart disease. QJM 1996; 89;579-589
Current vitamin D recommendations
• Current mod/severe deficiency <25nmol/L• Current mild deficiency <50nmol/L
– Considerable evidence that this is too low*
• Even at these levels, large proportion of population has low levels– Low levels correlate with osteoporosis, falls,
fractures, autoimmune disease and cancer* 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
• 80% of women, 70% of men in hostels and nursing homes in VIC, NSW, WA are vitamin D deficient– 97% had blood level below median of healthy
reference range*
• In Geelong women, 30% had vit D level <50nmol/L in summer and 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
Current vitamin D recommendations
• RDA now 200IU to prevent deficiency– Equivalent to about 5 seconds all over sun in
Perth summer at midday!
• Where these diseases uncommon blood levels are around 100-140nmol/L– 4 000IU/day gives level of 100nmol/L– 10 000IU/day gives level of 140nmol/L
Current vitamin D recommendations
• Current ‘LOAEL’ is 2 000IU per day– Good evidence that supplementing with
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#
* 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 not enough
• Simplest and cheapest is adequate sunlight
• Probably also helpful in other ways besides vitamin D (melatonin, etc)
• Solarium if no sun, but in very small doses
• Supplements – Can take a one-off supplement to get levels up
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
Recommendations: sunlight
• 10-15mins sunlight all over (in speedos) 3-5 times a week UV index 7 day (spring)– Proportionately more or less in winter and
summer– Solarium a reasonable alternative– Usually about 3mins in a 10min solarium– Check that has both UVA and UVB
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
• Supplement with 4 000IU per day (or more, up to 10 000IU) if no sun
• One off dose if levels low– 50 000-500 000IU if <25nmol/L
• Single dose of 600 000IU raised levels to 73nmol/L for people with levels <12.5nmol/L*
– 25 000-250 000IU if <50nmol/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
Target blood levels
• Check levels each autumn– Aim for at least 70nmol/L if well– Aim for 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
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)
• Try www.healthau.com for 5000IU capsule
• Or PSM Healthcare for 50 000IU monthly
Final recommendation
Enjoy your time in the sun!