Sunlight skin cancer and bones: Making sense of

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Sunlight skin cancer and bonesMaking sense of
mixed messages Seeta Durvasula Centre for
Developmental Disability StudiesUniversity of
Sydneyseetad_at_med.usyd.edu.au
CDDS Centre for Developmental
Disability Studies
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Sun exposure and skin cancer

• 1920s attitudes to sunlight exposure
• seen as health promoting
• tanned is beautiful
• In Australia, sun exposure causes
• 99 of non-melanoma skin cancers
• 95 of melanomas (Armstrong, 2004)
• So, strong public health campaigns for sun
  protective measures

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Sun Protection Measures

• Minimise time in the sun between 11am and 3pm
  (daylight saving time)
• Use shade wherever you can including trees,
  shelters and umbrellas
• Slip! on a shirt made from tightly woven fabric,
  with sleeves and a high neck or collar and other
  clothing that covers the skin
• Slop! on a broad spectrum water resistant
  sunscreen with an SPF rating of 30 and
• Slap! on a wide brimmed hat or legionnaire's cap,
  that shades the face, neck and ears.

NSW Health, 1999
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Slip, Slop, Slap

• Slip, Slop, Slap!It sounds like a breeze when
  you say it like thatSlip, Slop, Slap!In the sun
  we always say "Slip Slop Slap!
• Slip, Slop, Slap!Slip on a shirt, slop on
  sunscreen and slap on a hat,Slip, Slop,
  Slap!You can stop skin cancer - say "Slip,
  Slop, Slap!"

The Cancer Council Australia
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Vitamin D and Bones

• Hormone
• Necessary bone health
• helps absorb calcium from gut
• Beneficial effect on muscle strength and balance
• Prevention of fractures in elderly
• May also have beneficial effects on some types of
  cancer

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Where do you get it? (Vitamin D)

• In Australia, 90 from sunlight - UVB
• Food - minor source of Vitamin D in Australia
• milk, cheese
• margarine
• liver
• oily fish sardines, mackerel, salmon

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Pancreatic ? cells
non classical
classical
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What is Vitamin D Deficiency?(Position
statement, 2005)

• Defined by serum Vitamin D level
• Mild Vitamin D deficiency
• 25 (OH) vitamin D level - 25 50 nmol/L
• Insufficiency
• raised parathyroid hormone level
• Moderate Vitamin D deficiency 12.5-25 nmol/L
• Severe Vitamin D deficiency lt 12.5 nmol/L

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Vitamin D deficiency

• Increase in parathyroid hormone
• ? release of calcium from bones
• Reduced bone density
• osteomalacia in adults
• rickets in children
• Increased fracture risk in older people
• Muscle pains, muscle weakness
• Linked to falls in older people
• Associated with Type 1 diabetes, some cancers

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Causes of Vitamin D deficiency

• Inadequate sunlight exposure
• elderly especially in aged care facilities
• immobility
• skin covering
• Sunlight less effective
• ageing skin
• pigmented skin
• Diet low consumption
• Malabsorption and abnormal gut function

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How common is vitamin D deficiency?

• General population
• 43 in young women - Geelong (Pasco et al. 2001)
• 23 in adult population - SE QLD (McGrath et.
  Al, 2001)
• Specific groups at risk
• elderly in high level care 55 (Flicker et al.
  2003)
• dark skin pigmentation, especially if also
  covered/veiled
• 80 in one study (Grover Morley, 2001)

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People with developmental disability

• Studies mainly in institutionalised populations
  on anticonvulsant therapy
• 47 of people with developmental disability
  living in institution in NSW (Beange et al. 1994)
• 57 of those in a residential facility in SA
  those with poor mobility, difficulty in taking
  solids (Valint Nugent, 2006)
• Community living adults - 36 men and 40 women
  (Centre et al. 1998)
• 43 of a clinic population in Sydney older
  people, people with Down syndrome, overweight
  (Durvasula et al. 2005 - unpublished)

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Prevention of Vitamin D deficiency in general
population

• Diet
• 200IU if lt 50yrs 400IU if 51-70 yrs 600 IU if
  gt70yrs (US Food Nutrition Board)
• Most Australians get lt100 IU/day
• Sun exposure 1/3 Minimal Erythema Dose (MED)
• To Reduce fracture risk in elderly 1000IU day

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Recommended sun exposure

• 1 minimal erythema dose (MED) is amount of sun
  exposure which produces faint skin redness
• Whole body exposure to 10-15mins of midday
  sun in summer
• 15,000U of vitamin D
• Recommend 1/3 MED
• exposing hands, face and arms to of sunlight on
  most days

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Recommended sun exposure times (mins) for 1/3MED
for moderate fair skin

• Region Dec-Jan July-Aug
• at 10 am or 2pm
• Auckland 6-8 30-47
• Christchurch 6-9 49-97
• Cairns 6-7 9-12
• Brisbane 6-7 5-19
• Adelaide 5-7 25-38
• Perth 5-6 20-28
• Sydney 6-8 26-28
• Melbourne 6-8 32-52
• Hobart 7-9 40-47

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Sun exposure in people with developmental
disability

• Paucity of reliable data except for those
  physical disability, or those in institutional
  care
• Possible other at risk groups
• e.g those with challenging behaviour, autism
• Note Reliance on carers/ support staff

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Mixed messages?

• Sun protection prevent skin cancer
• Sun exposure prevent vitamin D deficiency

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Not so mixed

• Risks and Benefits of Sun Exposure (2005)
• Aust. and NZ Bone Society, Osteoporosis
  Australia, Australasian College of
  Dermatologists, The Cancer Council of Australia
  http//www.cancer.org.au/content.cfm?randid299825

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Recommendations

• Sun protection required when UV index is moderate
  or higher (3)
• Most people achieve adequate Vitamin D levels
  through typical day to day activities, without
  deliberately seeking additional sun exposure
• summer expose face, arms and hands to average
  of 5 minutes most days of the week outside peak
  UV levels
• winter, in Southern States exposure of hands,
  face, arms for 2-3 hours over a week
• Use of solaria not recommended due to level of UV
  exposure

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Recommendations

• Those at increased risk of skin cancer need more
  vigorous sun protection practices and should
  discuss their vitamin D requirements with their
  doctor
• Those at increased risk of Vitamin D deficiency
  should discuss their vitamin D status with their
  doctor

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Recommendations special groups

• Older adults if not at high risk of skin
  cancer, ensure incidental exposure
• Skin type dark skin pigmentation, especially if
  covered may need vitamin D
  supplementation

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What about sunscreen?

• Necessary to prevent skin damage if prolonged
  exposure (long enough to cause erythema) is
  planned
• For incidental exposure, of less than 10 minutes,
  may be able to omit sunscreen
• short exposures better for vitamin D synthesis
• (Nowson et al, 2004)

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What about people with developmental disability?

• Recommendations as for general population for
  prevention of vitamin D deficiency
• i.e. safe sun exposure
• But, need to take into account skin
  type/pigmentation, latitude, season, medication
  use (anticonvulsants), mobility

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What about people with developmental disability?

• However, many are at increased risk of Vitamin D
  deficiency e.g.
• Medications
• Limited sun exposure
• poor mobility
• staffing limitations
• challenging behaviour
• Therefore, incidental sun exposure may not be
  enough

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Recommendations

• Vitamin D insufficiency is common in people with
  developmental disability and can only be
  confirmed by measuring 25OH D
• Either monitor yearly at end of winter (lowest
  values) and treat those lt 50nmol/L with vitamin D
  supplements
• Optimal calcium intake also needed diet or
  supplements

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Message not so mixed

• Incidental safe sun exposure where possible
• Check Vitamin D levels and treat if required
• Need further research
• Identify those with developmental disability who
  are especially at risk
• Determine levels of sun exposure in those living
  in the community

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Management Vitamin D Deficiency

• 3000 5000 IU/day ergocalciferol for 6-12 weeks
• 50 000 IU cholecalciferol. One tablet monthly for
  3-6 months (NZ only)
• Reassess after 3-4 months of treatment
• 1000 IU/day of ongoing treatment required for
  most patients
• Contraindicated in hypercalcaemia