One in three people around the world are not getting enough vitamins and minerals, a report suggests.
Vitamins can affect IQ
Officials say it is preventing millions of people from meeting their physical and intellectual potential.
The report, by Unicef and The Micronutrient Initiative, calls for urgent action to tackle the problem.
It says efforts to eradicate poverty, reduce child mortality and improve maternal health all hinge on ensuring better access to vitamins and minerals.
Range of problems
Vitamin and mineral deficiencies can cause a range of problems ranging from lower IQs to weak immune systems.
A lack of iodine, for instance, is estimated to cause as many as 20m babies to be born with mental impairments.
A lack of vitamin A is believed to cause as many as 1m deaths in children under the age of five every year because of poor immunity.
Worst affected countries
5. Burkina Faso
Based on estimates of proportion of GDP lost to vitamin/mineral deficiencies
A study, published on Monday, found one in five people around the world are not getting enough zinc in their diet, increasing the risks of diarrhoea and pneumonia.
In more severe cases, vitamin and mineral deficiencies can lead to anaemia and blindness.
The report calls on the food industry to consider adding key vitamins to staple foods to tackle the problem.
It also calls for supplements to be made available to millions of people in developing countries.
In addition, it urges governments to do more to fight diseases like malaria, measles and diarrhoea which can prevent people from absorbing vitamins and minerals properly.
"The overwhelming scope of the problem makes it clear that we must reach out to whole populations and protect them from the devastating consequences of vitamin and mineral deficiency," said Carol Bellamy, executive director of Unicef.
"All children have the right to a good start in life," said Kul Gautum, its deputy executive director.
"With nearly a third of the planet affected in some way by a problem for which a clear solution exists, anything less than rapid progress is unconscionable."
Venkatesh Mannar, president of The Micronutrient Initiative, a not-for-profit organization which is trying to boost vitamin uptake in developing countries, urged the international community to work together.
"Resources and technology to bring vitamin and mineral deficiencies under control do exist.
"What we need is the will and the effort and the action to fix this problem."