Zinc is an essential micronutrient for human health. The adult body contains about 2-3 grams of zinc. Zinc is vital for many biological functions and plays a crucial role in more than 300 enzymes which keep the metabolism going. Zinc is essential for the synthesis of protein and DNA and the development of genes. It accelerates cell division and is vital for normal growth and physical and mental development in infants, children and teenagers. Zinc is also important for the proper functioning of the immune system and can reduce the duration and severity of a range of infections spanning from a simple common cold to severe diarrhea and pneumonia.
Zinc is supplied to the body through a diversified diet but this is inaccessible to large parts of the population in developing countries who live on crops which are often low in zinc, particularly when grown on zinc deficient soils. In addition, crops contain phytates which inhibit the absorption of zinc.
Two billion people worldwide suffer from malnutrition mainly due to an insufficient intake of zinc and other key vitamins and micronutrients through their diets. Young children in developing countries are most impacted. Zinc deficiency weakens their immune system and increases the risk of dying from common childhood infections such as diarrhea, the second leading cause of under-five mortality.
When diarrhea lasts several days it can deprive the body of essential fluids and nutrients. In developing countries where hygiene, sanitation and health care are less readily available diarrhea can lead to severe, life-threatening dehydration. Each year diarrhea claims the lives of 760,000 children under five years.
Diarrhea is treatable. A 10-14-day course of 20mg of supplemental zinc reduces the duration of diarrhea by 25% and the stool volume by 30% and staves off further bouts for three months.
Zinc deficiency is also associated with stunting. In 2013, UNICEF, WHO and World Bank indicated that an estimated 161 million children under five years - or 25% of all children in this age category - were permanently stunted worldwide as a result of chronic malnutrition during early childhood. Stunted children are not only short for their age, but their brain does not develop its full potential with devastating long-term consequences on health, learning and future earning potential. This in turn affects the development potential of a nation.
The 2008 Lancet series on Nutrition estimated that 450,000 under-five death could be directly linked to zinc deficiency. In the same year the Copenhagen Consensus - a group of internationally acclaimed economists, including five Nobel Laureates - concluded that combating the world’s malnutrition problem through the provision of vitamin A and zinc ranked high among the various cost-effective solutions to the world’s pressing problems. They calculated that for every dollar invested in zinc supplements, there would be a return of US$ 17.
Zinc`s effectiveness for child health and survival had been well documented since the 1990s but it took another decade before it was included in child survival programs. In 2004 UNICEF and WHO launched a joint statement recommending zinc in combination with oral rehydration salts for the effective treatment of diarrhea. Diarrheal disease were then responsible for 2 million deaths of children under five years. Since then diarrhea mortality dropped more than 60% to 760,000 under-five deaths in 2013.
In 2013 UNICEF and WHO launched “The Integrated Global Action Plan for Pneumonia and Diarrhea” to accelerate country-based efforts in drastically reducing these two preventable and major causes of child deaths by 2025.
Additionally, the international community has been joining forces by launching a number of high-level initiatives to accelerate progress to reduce stunting with focus on the first 1000 days in the life of a child from conception up to 24 months. This is the period when improvements in nutrition can make a real difference in the development of a child. Interventions after age two when the development of the brain and nervous system are largely complete doesn`t have the same impact.
Zinc supplementation plays a crucial role in all these programs and has the potential of saving the lives of hundred thousands of children over the next ten years.