Table 4.

Examples of clinical conditions that show low zinc levels

Condition/disease	Possible reason for low zinc level and the clinical status
Infection with HIV	Reduced absorption of zinc from foods. These patients often have diarrhoea, which causes excess zinc loss, resulting in low serum zinc [128]
Chronic kidney disease	Serum zinc levels tend to be on the lower side due to inadequate dietary intake, malabsorption and zinc removal during haemodialysis [129]
Liver diseases	Alcoholic hepatitis patients showed lower zinc levels compared to non-alcoholic liver disease patients [130]. Patients with alcoholic liver disease often have poor diets low in zinc whilst in cirrhosis, absorption may be impaired and there usually is increased urinary zinc excretion [131]
Polycystic ovarian syndrome that increase oestrogen levels [132]	High levels of oestrogen can decrease plasma zinc levels and increase zinc in the liver [130]
Sickle cell disease or beta thalassaemia	These patients require frequent blood transfusions, which lead to iron loading. The latter is tackled via iron chelation, but this could lead to zinc deficiency, a common complication of sickle cell treatment [133]