Vit D study looks at migrants' health
People with darker skin are at risk of developing dangerously low levels of vitamin D after moving to New Zealand, a leading health researcher says.
Massey University lecturer Pamela von Hurst is one of New Zealand's top authorities on vitamin D.
She says immigrants from warm climates like Africa and parts of Asia are at risk of crippling diseases if they do not get enough exposure to the sun.
"We see it especially in refugee diasporas from conflict states in Africa like Sudan and Somalia. They have literally black skin," Dr von Hurst says.
"When they're moving to places like New Zealand and Northern Europe they're struggling to make enough vitamin D to stay healthy."
Dr von Hurst says someone with dark skin may need to spend up to 10 times as long in the sun to make a healthy amount of vitamin D when compared to someone with fair skin.
A study involving 81 Auckland women of Indian, Pakistani and Sri Lankan origin found that 84 per cent were vitamin D deficient.
Dr von Hurst puts it down to changes in lifestyle such as avoiding the sun out of fear it could damage their skin.
"We also see it in Asian populations where they are very conscious about maintaining the paleness of their skin," she says.
Misconceptions about dark skin also do little to help sun behaviours, she says.
"We hear it all the time, ‘I don't need to worry about getting sun because I've got naturally dark skin'.
"Whereas in reality, the darker your skin the more exposure you need."
It is about achieving the balance between healthy exposure and avoiding skin damage, she says.
Vitamin D deficiency increases the risk of respiratory infections like pneumonia and tuberculosis, and causes muscle pain and weakness, Dr von Hurst says.
Mental health issues like depression and autism have also been linked to a lack of the vitamin.
"In Sweden the Sudanese and Somalian people call autism the Swedish sickness," she says.
The accepted minimum level of vitamin D in New Zealand is 50 nanomoles per litre.
According to Ministry of Health data about 32 per cent of New Zealanders aged 15 and older are below this level.
A general guideline for sun exposure is impossible, Dr von Hurst says.
"You cannot say ‘OK you need to spend X amount of time in the sun'.
"It depends so much on the person, their skin colour and their age."
WHERE YOU GET IT
Sources of Vitamin D Exposure to ultraviolet B (UVB) from sunlight is the main source.
Between September and April the Ministry of Health recommends outdoor activity in the early morning or late afternoon.
Some foods like oily salmon and tuna, and fortified milks and yoghurts contain small quantities.
Supplements available without a prescription from your local pharmacy.
- © Fairfax NZ News
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