Zinc Deficiency An Emerging Issue
Zinc is a micronutrient essential to the body. The significance of zinc in human nutrition and public health was recognised relatively recently. Numerous aspects of cellular metabolism are zinc dependent. Nearly 100 different enzymes depend on zinc for their ability to catalyse vital chemical reactions. Zinc plays important roles in human growth and development, immune response, neurological functions and reproduction.
Food sources of zinc include meat, particularly liver, poultry, certain seafood like oysters, eggs, beans, nuts and legumes, whole grains and dairy products, Zinc bio-availability is relatively high in meats, eggs and seafood because of the relative absence of compounds that inhibit zinc absorption and the presence of certain amino acids
that improve zinc absorption.
Ideally, people would eat enough zinc-rich food but that is not the case for a number of reasons. It has become clear over the past decades that many suffer from zinc deficiency. Poor people simply do not have access to sufficient amounts of zinc rich food.
The individuals at risk of zinc deficiencies include infants and children, pregnant women and lactating mothers, malnourished individuals and individuals with persistent diarrhoea.
According to the National Academy of Sciences (USA), the Recommended Dietary Allowance (RDA) of zinc is 12 milligrams per day for women, 10 milligrams per day for men and 3-5 milligrams for children 3-5 years.
Mild Zinc deficiency contributes to impaired physical and neuropsychological development, and increased susceptibility to life-threatening infections in young children.
Growth retardation or failure to thrive is common features of mild zinc deficiency.
Zinc supplementation has been associated with improved neuropsychologic functions. Adequate zinc intake is essential in maintaining the integrity of the immune system. The adverse effects of zinc deficiency on immune system function are likely to increase the susceptibility to infectious diarrhoea, while persistent diarrhoea contributes to zinc deficiency and malnutrition.
Diarrhoea is still one of the major killer diseases of the under fives in our country. Various studies have shown that zinc provides a very effective treatment for diarrhoea, particularly for children under five. Zinc treatment reduces the severity and duration of diarrhoea as well as the likelihood of future episodes of diarrhoea and the need for hospitalisation. Zinc supplementation in combination with Oral Rehydration Therapy has been shown to significantly reduce the duration and severity of acute and persistent diarrhoea and to increase child survival.
Severe zinc deficiency results in slowing or cessation of growth and development, delayed sexual maturation and impotence, immune system deficiencies, loss of appetite, impaired wound healing, chronic and severe diarrhoea,anaemia and behavioral disturbances.
ICDDRB has initiated a project entitiled 'Scaling Up Zinc Treatment for Young Children with Diarrhoea-abbreviated as SUZY Project. The Project aims at production and marketing of zinc tablets and relevant further research on zinc therapy for young children with diarrhoea and pneumonia.
The treatment of diarrhoea is a 20 mg tablet daily for duration of 10 days. The treatment is ideal for children 6 months to 5 years and there are no proven side effects. Like Vitamin B,zinc is not stored in the body, so only the required amount is absorbed in the body.
Zinc supplementation may also reduce the incidence of lower respiratory infections, such as pneumonia, which is another cause of child mortality. Acute Respiratory Infections (ARI) account for 17 percent and Diarrhoea for another 9 per cent of child mortality (BDHS 2004). Zinc treatment, therefore, holds tremendous potential as a public health intervention and given together with Vitamin A could have a positive impact on child survival.