Zinc is an essential dietary micronutrient because of its fundamental role in gene expression, cell development, and replication during all life stages particularly pregnancy, childhood, and adolescence.
Zinc is naturally present in cereals, pulses, nuts, dairy products, red meat, and poultry. However, the prominent cereal and pulse-based vegetarian Indian diet contains phytates that bind zinc and inhibit its absorption causing a deficiency. Additionally, zinc is not well conserved in the body. Hence, zinc deficiency is directly related to its dietary intake. Therefore, inadequate intake, increased losses, and increased demands of zinc are the causes of the deficiency.
The consequences of deficiency are diverse. The severity of these consequences depends on the severity as well as the duration of the deficiency along with the age and sex of the patient.
Many of the symptoms of zinc deficiency are non-specific and often associated with other health conditions which affect different body systems and cause problems such as:
1. Skin problems
Zinc is indispensable for growth and tissue maintenance. Its deficiency may cause alopecia, non-healing ulcers and delayed wound healing. Severe deficiency can cause skin rashes.
2. Appetite changes and gut disturbances
Zinc deficiency can cause symptoms such as anorexia, loss of appetite, and loss of taste sensation. It can cause diarrhea that further increases zinc losses, resulting in a vicious cycle of worsening deficiency.
3. Cognitive impairment
Zinc deficiency may adversely affect the fetal brain function and cognitive development amongst neonates and infants, neuropsychological performance in children, and cognitive function in the elderly. It may also cause an altered smell sensation.
4. Weak immunity
A zinc deficiency could render cells susceptible to oxidative damage which further affects the DNA and the cell membrane. Severe zinc deficiency depresses immune function. In fact, even mild to moderate degrees of deficiency can compromise cellular and humoral immunity, leading to increased susceptibility to recurrent infections such as diarrhea, pneumonia, and malaria.
5. Growth issues
Growth retardation and short stature can occur due to the anorectic effect of zinc deficiency which decreases substrate availability by reducing food intake. Growth failure does not respond to the restoration of energy and amino acid supply until zinc status has been corrected.
6. Sexual performance issues
Zinc deficiency can cause gonadal hypofunction, delayed sexual maturation, impotence, and decrease plasma testosterone concentrations as well as fertility. Deficiency during pregnancy has diverse effects on the fetus, including prematurity, complicated delivery, low birth weight, and congenital abnormality.
Zinc deficiency has also been a risk factor for night blindness, premature atherosclerosis, malabsorption syndrome, chronic liver disease, chronic renal disease, sickle cell disease, diabetes, malignancy, and other chronic illnesses.
Zinc (lozenges or syrup) is beneficial in reducing the duration and severity of the common cold in healthy people when taken within 24 hours of the onset of symptoms. Zinc supplementation has proved to be beneficial in patients with chronic leg ulcers or arterial or venous ulcers, pneumonia, and vision loss.
In the current pandemic, it is imperative to include zinc-rich food items or zinc supplementation to reduce oxidative stress and boost immunity to fight the infection.