Zinc is an essential micronutrient commonly found in red meat, poultry, fish, beans, nuts and whole grains. Despite a wide variety of zinc food sources, the prevalence of zinc deficiency worldwide is common, with a staggering prevalence of about 31% with 17,3% of the population being at risk for zinc deficiency. The primary reason for zinc deficiency is due to inadequate intake from diet.
How common is zinc deficiency?
In South Africa, specifically, the prevalence of zinc deficiency is as high as 62%. Pockets of inadequate zinc intakes have been identified among segments of the South African population, such as infants, children, and the elderly.
After iron, zinc is the most abundantly distributed micronutrient in the body. Zinc is essential for the activity of over 100 enzymes (proteins in the body that help speed up chemical processes in the body). Zinc importantly plays a role in the immune function, and supports normal growth and development during pregnancy, childhood and adolescence, as well as wound healing.
As amazing as the body is, it has no specialised zinc storage system and thus a daily intake of zinc is required in order to maintain a steady state in the body.
What are the signs of zinc deficiency?
Zinc deficiency is characterised by growth retardation (impaired growth in infants and children), loss of appetite and impaired immune function. Severe zinc deficiency may be characterised by hair loss, diarrhoea, delayed sexual maturation, weight loss, delayed healing of wounds, taste abnormalities and mental lethargy.
Severe zinc deficiency may impair the immune system from functioning adequately, and mild to moderate zinc deficiency may cause a significant decrease in the key immune cells involved in vital immune responses. Zinc is required to develop and activate key white blood cells involved in the immune system. This however can be corrected by zinc supplementation.
The impact of zinc deficiency on impaired immune function may explain why low zinc status has been associated with an increased susceptibility to infections, such as those that cause diarrhoea, especially in children, and even pneumonia.
Why is zinc important?
Zinc plays essential roles in the development of the central nervous system across the lifespan from early neonatal brain development through the maintenance of brain function in adults.
Zinc deficiency during pregnancy and lactation has been shown to be related to many congenital abnormalities of the nervous system.
Additionally, insufficient levels of zinc in children have been associated with lowered learning ability, apathy, fatigue and mental retardation/delayed mental development.
Cognition is the mental process of acquiring knowledge and understanding through skills of perception, thinking, memory, learning and attention.
Zinc deficiency may affect cognitive development by variations in attention, activity, neuropsychological behaviour and motor development.
Additionally, Vitamin D is also important with the immune response. Vitamin D can modulate the innate and adaptive immune responses. Deficiency in vitamin D is associated with increased autoimmunity and an increased susceptibility to infection.
Zinc importantly plays a role in the immune function, and supports normal growth and development during pregnancy, childhood and adolescence, as well as wound healing, making it an essential micronutrient required by the body.
