'Hoodies' bad for your health - doctor

Cutting themselves off from the sun - 'hoodies' being worn in Auckland yesterday. Picture / Dean Purcell

"Hoodies" may be depriving Kiwi youngsters of the sunlight they need to build their bones and stay energised.

A doctor who works at Child, Youth and Family Services' youth justice centre at Wiri, Dr Glenn Twentyman, said yesterday that every young person he had tested at the centre had deficient vitamin D, which helps the body absorb vital minerals into the bones.

"It's the hoodies and the hats and the downward glance of the teenagers, shading your face all the time," he said.

"A lot of these kids stay away from sunshine. They don't hang out at the beach or in the bush. Some are into drugs and alcohol and a lot of it is indoor activity and night-time activity. They sleep during the day. They are wearing those hoods and literally they don't get out in the sun."

His comments add to mounting evidence of increasing vitamin D deficiency in Australasia, partly caused by "covering up" to avoid skin cancer. Ozone depletion has exposed the region to higher ultra-violet radiation, giving New Zealand the world's highest rate of skin cancer.

A four-year study led by Dr Cameron Grant at Auckland's Starship hospital found that 10 per cent of Auckland infants did not have enough vitamin D.

Dr Grant said yesterday that Dr Twentyman's hoodie theory was not unreasonable.

"We know that vitamin D deficiency is a health issue in New Zealand. We know that people who are at risk of vitamin D deficiency are for example groups who keep themselves clothed and keep themselves indoors for religious reasons ... so his idea is not an unreasonable one."

A study of pregnant women in a multicultural Wellington suburb this year found that 87 per cent were deficient in the vitamin.

Last month Waikato paediatrician John Goldsmith said he was seeing increasing cases of rickets, a disease caused by vitamin D deficiency which can cause bone deformities.

Dr Twentyman, who also works at the Holistic Medical Centre in Pt Chevalier and runs a High St men's clinic, said vitamin D deficiency was very common among depressed people and the elderly, such as those kept indoors in rest homes all day.

Holistic Medical Centre director Rebecca Jones said all patients who came in tired, not sleeping well or depressed were tested for vitamin D, and all but two of those tested this winter had below the level of 100 nanomoles per litre of body fluid believed necessary for good physical and mental health.

Between 30 and 40 per cent had below 50 nmol/L, the cutoff point recommended by the World Health Organisation and used in the Wellington study. Dr Twentyman said all the youths tested at the Wiri youth justice centre had under 100 nmol/L, and most had under 50. Yet the deficiency was "cheap and easy to cure" with vitamin D tablets.