The Ministry of Health is being urged to ensure tests for Vitamin D deficiency are priced so they are affordable for everyone.
A University of Harvard study of more than 900 New Zealand children found that a deficiency of the vitamin contributes to the risk of respiratory infections.
New Zealand's rate of the respiratory infection bronchiolitis is about twice that of the United States.
Lead scientist Carlos Camargo says everyone needs an adequate supply of Vitamin D for all-round good health.
Vitamin D comes mainly from sunlight, but Dr Camargo says with New Zealand also having a world leading rate of melanoma (skin cancer), the answer lies in taking a supplement.
Because overdosing on Vitamin D can be harmful, he says everyone should have a test to see how much they actually need and he would like to see the Health Ministry facilitate that.
Dr Camargo says how much sunshine someone should get is unknown without a test.
"Going outside, even in the winter in New Zealand, you're not going to make any Vitamin D - you need to get it from something else.
"Food is not a very good way of getting it, because the amounts are so small, so you take the supplements. But then you need to monitor how you're doing - because people absorb that supplement differently - and the only way to do that is through testing."
The study is published in the January 2011 edition of Pediatricsmagazine, the official journal of the American Academy of Pediatrics.
Diseases on rise in developed countries
An associate professor in paediatrics at the University of Auckland says diseases associated with Vitamin D deficiency are on the rise in developed countries.
Grant Cameron says people get less sunshine now than 50 years ago.
"Vitamin D deficiency has returned as a health issue in a number of countries where it had previously become quite rare, for example, the United States and the United Kingdom.
"We've started looking at this for the first time in New Zealand and have appreciated that it is a common problem here and may well have been a common problem for some time."
Dr Cameron says research indicates that one in 10 New Zealand children had a deficiency low enough to put them at risk of the bone disease rickets.
