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Copenhagen Consensus Center

Micronutrient Supplements: Vitamin A and Zinc

The Challenge

Vitamin A and Zinc are specific micronutrients that are both vital for child survival.

When a child does not get enough vitamin A, there is a higher risk of illness and death from common infections like diarrheal disease and measles. Vitamin A is also vital for eyesight: deficiency is the leading cause of preventable blindness in children. The World Health Organization estimates that 250,000 to 500,000 vitamin A-deficient children become blind every year. Half of them die within 12 months of losing their sight.

In pregnant women, lacking vitamin A can cause night blindness and can increase the risk of death.

Vitamin A occurs naturally in breast milk and in some fruits and vegetables, as well as in beef, pork, turkey, chicken and fish livers. Up to 250 million children worldwide do not get enough vitamin A in their diet. It is estimated that deficiency causes about six percent of under-five year-old deaths. Vitamin A deficiency is worst in South Asia and sub-Saharan Africa

Zinc deficiency can impair the immune system and increase the risk of death from common childhood infections including diarrhea, pneumonia, and malaria. It can also cause stunted growth, hair-loss, and lesions.

Zinc occurs naturally in many foods, but animal meat is an important source. Zinc is effective at treating acute cases of diarrhea. Currently 1.9 million children die annually because of diarrhea.

More than one billion people are susceptible to zinc deficiency. Regions with high risk of zinc deficiency include South Asia, sub-Saharan Africa, and several countries in Latin America.

Zinc and vitamin A deficiency often occur together. Zinc is required to help transport vitamin A through the body. A deficiency in zinc limits the body's ability to move vitamin A stores from the liver to body tissues.


The Solution

Deficiencies in both vitamin A and zinc can be remedied with supplements.

Good progress has been made tackling vitamin A deficiency among children. Approximately 70% of children aged under-five in South Asia and sub-Saharan Africa are covered with two preventative, protective doses of vitamin A every year.

Despite this progress, this life-saving initiative needs to be extended until there is universal coverage. The millions of children who are still not reached are often the poorest and most vulnerable. Moreover, coverage varies a lot in many countries: during one half-year there may be high levels of supplementation, while in the next half-year, there may be none. And there are not enough successful programs designed to supply vitamin A to breastfeeding mothers. Programs only exist in two-thirds of high-risk countries, and most are limited in scope.

There is another challenge associated with extending vitamin A coverage. Since the 1990s, vitamin A supplements have been delivered with polio vaccinations on National Immunization Days in many countries. However, as the polio immunization days are phased out because of the success of that program, many nations face the challenge of maintaining the necessary high coverage of vitamin A twice a year.

Zinc supplements are effective in treating bad cases of diarrhea in malnourished children but their provision has not yet been widely adopted. Studies from India, Africa, South America and Southeast Asia show that children suffering from diarrhea get better faster after taking zinc supplements.


The Research

In ‘Micronutrient Supplements for Child Survival’, a Best Practice Paper for the Copenhagen Consensus Center, Sue Horton et al. outline ways to make vitamin A coverage universal. Although it is often assumed that the children not reached by vitamin A supplementation live in remote areas, Horton et al. find that many live in or around big cities such as Nairobi and Delhi which have a weak urban health infrastructure.

They find that a Bangladeshi program provides a good model for how to achieve universal coverage. In this program, community groups and volunteers focused on reaching families with children who had not received supplements. Horton et al. also argue that there is a missed opportunity in many developing countries to provide vitamin A to pregnant and recent mothers. They recommend that when newborn children receive their first immunization, mothers should also receive vitamin A supplements.

Horton et al. point out that only a very small number of countries have launched zinc policy initiatives or pilot programs. And there are no large-scale, comprehensive programs anywhere.

They outline the work that is required – including policy advocacy, technical assistance, capacity building, and additional financing – to support the international scale-up of zinc supplementation.

Horton et al. estimated the cost of delivering vitamin A and zinc supplements by region. The costs are very low, and vary based on personnel costs. The estimated per-child cost of increasing Vitamin A supplementation to 80-90% of the population of South Asia, Sub-Saharan Africa and East Asia is $2.40, while the estimated cost of achieving 40% Zinc coverage in the same regions is just $1.00 per child.

It is possible to put a monetary value on the benefits of increased vitamin A and zinc supplementation. The Copenhagen Consensus Center research shows that the benefits are very large. For treatment of pre-school aged children, each dollar spent on these initiatives results in around $17 of benefits. In the worst-affected countries, the benefits of supplementation with vitamin A and zinc can be up to 100 times higher than the costs.


Where to Find Out More

The Copenhagen Consensus research that this section draws from:

Micronutrient Supplements for Child Survival (Vitamin A and Zinc): Best Practice Paper

Sue Horton, France Begin, Alison Greig and Anand Lakshman.

Hunger and Malnutrition: Copenhagen Consensus 2008 Assessment Paper

Sue Horton, H. Alderman, J.A. Rivera

Hunger and Malnutrition Chapter 

in Global Crises, Global Solutions, second edition

Edited by Bjorn Lomborg

The Expert Panel's individual rankings and further elaboration can be found in the book, Global Crises, Global Solutions, second edition.