The study has found that 12 per cent of Auckland children aged from six months to two years does not have enough vitamin A, a deficiency that causes blindness in more than 250,000 children in developing countries each year.

Despite the popularity of dieting, and mounting concerns about childhood obesity, the study also showed that many New Zealanders either do not know what is good for them and their children to eat, or cannot afford to buy the foods they need. If you want to know more about these subjects look through our articles at GKA our email us.

Dr Grant also leads a study on Auckland's rate of childhood pneumonia, which is five to 10 times higher than in the United States.

He said the high rate of such diseases was due partly to increasingly overcrowded houses in the past 10 to 15 years, and variable access to family doctors. But it now seemed that illness also stemmed partly from poor diet.

Vitamin A, which is made in the body mainly from red fruits and vegetables such as peaches and carrots, is crucial for seeing at night. It also helps to protect the body against infectious diseases such as pneumonia and measles. "If a child is admitted to hospital with measles, we give them a treatment of vitamin A," he said.

Humans need only a tiny amount of iron in the diet, around a hundredth of a gram a day. Yet it is essential to make the haemoglobin molecules in blood that carry oxygen around the body and give people strength and energy. Low iron levels make infants tired, lethargic and prone to infections.

Dr Grant said the 24 per cent rate of iron deficiency in his study was similar to studies in the US 30 years ago, where the deficiency is now about 10 per cent with iron supplements common in food.

"We have babies admitted to hospital with vitamin D deficiency which is so severe that they have rickets, and their calcium levels in the blood are so low that they have convulsions," Dr Grant said.

His study is based on a random sample of 416 infants in the Auckland region. Blood tests were taken between 1999 and 2002.

Article sourced from www.stuff.co.nz