Iodine deficiency in pregnancy is causing as many as 20 million babies a year to be born mentally impaired, says Unicef, while vitamin A deficiency, which compromises the immune systems of approximately 40 per cent of children under five in the developing world, is killing 1 million youngsters each year.
But while the problem could scupper UN goals of eradicating extreme poverty and reducing child mortality by two-thirds by 2015, effective and inexpensive methods to control vitamin and mineral deficiencies do exist.
The report calls for the food industry to develop and distribute low-cost fortified foods and supplements and for governments to create a supportive environment to allow such products to reach the affected populations.
Methods that have worked in industrialised nations are now so inexpensive and available that they could control vitamin and mineral deficiencies worldwide, said Unicef executive director Carol Bellamy, presenting the report at the annual meeting of the UN Standing Committee on Nutrition in New York.
Distribution of low-cost tablets, capsules and syrups has already resulted in significant gains during the past decade. A sustained effort to add iodine to salt consumed by two-thirds of the world's households has protected approximately 70 million newborns a year, in some degree, against mental impairment, says Unicef.
And more than 40 developing countries are now reaching two-thirds or more of their young children with at least one high-dose vitamin A capsule every year, saving thousands of lives and preventing the irreversible blindness of hundreds of thousands more.
"Resources and technology to bring vitamin and mineral deficiencies under control do exist," said Venkatesh Mannar, president of the Canada-based Micronutrient Initiative. "What we need is the will, the effort and the action to fix this problem."
Another report, presented at the meeting yesterday, shows that up to one-fifth of the world's people lack sufficient zinc in their diet, while an estimated one-third live in countries considered at high risk of zinc deficiency.
The International Zinc Nutrition Consultative Group (IZiNCG), set up by the Micronutrient Initiative and Unicef, says the relatively high price of zinc-rich foods such as red meat and shellfish, legumes and whole grain cereals contributes to zinc deficiency, a problem much more common and harmful to health than previously believed.
Countries at high-risk are mostly in South and Southeast Asia, sub-Saharan Africa, Central America and the Andean area of South America. But while more research is needed to better measure the size of the problem and identify specific sub-groups at highest risk, knowledge of zinc deficiency and its importance to human health has increased greatly in recent years, according to Dr Ken Brown, a professor of international nutrition at the University of California, Davis, who co-chairs the group's Steering Committee.
A number of community-based, controlled intervention trials have been conducted in lower income countries in the past decade, which consistently show that diarrheoa and respiratory infections, among the most common causes of child mortality in developing countries, are reduced by providing additional zinc, he said.
Early evidence indicates that mortality rates are reduced by 50 per cent or more among zinc-supplemented children in high risk settings.
"There is also some evidence that infants of mothers who received zinc supplements during pregnancy have less diarrhea during the first months of post-natal life," said Dr Brown.
The research cites several options for combating zinc deficiency, including supplements or specially formulated zinc-fortified foods, national programmes to fortify staple foods (already employed to deliver other nutrients such as iron and folic acid), and public education on good dietary sources of the nutrient.
"It is hoped this document will serve to promote greater awareness among key public health decision makers of the importance of zinc nutrition and help governments, international agencies, and private organizations to ameliorate or, ideally, prevent health problems related to inadequate zinc intake," said Cutberto Garza, professor at Cornell University and director of the UN University's Food and Nutrition programme.
The report, available on the IZiNCG website, will be circulated to nutrition and health programme officers in developing countries by the Micronutrient Initiative and Unicef.