Zinc — what does the body need it for, and when are people most likely to be deficient, according to doctors?

Aim of the study: Zinc deficiency is commonly overlooked in developed countries. It occurs in infants, children, and adolescents during critical periods of growth. This review aims to present evidence on zinc deficiency and toxicity, as well as their treatment in children.

Results: Over the last decade, the importance of zinc deficiency for childhood growth, illness, and mortality has been recognized through a number of large-scale supplementation trials in underdeveloped countries. Recognition of the recent nationwide shortage of injectable zinc for supplementation in total parenteral nutrition over the last 2 years has focused attention on the possibility of zinc deficiency in the United States.

Aim of the study: Vegan diets, which exclude animal products and all their by-products, have gained popularity, especially over the last decade. However, this type of diet has not been adequately assessed in the scientific literature. This study aimed to investigate whether vegan diets in European populations provide adequate nutrition, and to compare their macro- and micronutrient intake with World Health Organization recommendations.

Results: In terms of macronutrients, vegan diets provide less protein than all other types of diet. Veganism is also associated with low intake of vitamins B2, niacin (B3), B12, and D, as well as iodine, zinc, calcium, potassium, and selenium. Vitamin B12 intake among vegans is significantly lower (0.24–0.49 μg, compared with the recommended 2.4 μg), and most vegans consume less calcium than recommended (750 mg/day). No significant differences in fat intake were observed. Vegan diets are not associated with deficiencies in vitamins A, B1, B6, C, and E, iron, phosphorus, magnesium, copper, or folate, and they have a low glycemic load. Following a vegan diet may result in deficiencies in micronutrients (vitamin B12, zinc, calcium, and selenium), which should not be ignored. However, low micro- and macronutrient intake is not always associated with health problems. People who follow a vegan diet should be aware of the risk of potential dietary deficiencies.

Aim of the study: Zinc and selenium are essential trace elements involved in important (patho)physiological processes. The prevalence and prognostic implications of zinc and selenium deficiency in patients with advanced chronic liver disease (ACLD) remain unknown.

Results: Among 309 ACLD patients (median age: 57 [IQR: 50–64], MELD: 11 [IQR: 9–16], HVPG: 17 [IQR: 11–20]), 73% (227) and 63% (195) were deficient in zinc and selenium, respectively. Patients with decompensated disease (dACLD) had significantly lower serum zinc levels (median: 48 [IQR: 38–59] vs. 65 [IQR: 54–78] in patients with compensated disease, cACLD; p < 0.001) and selenium levels (median: 4.9 [IQR: 4.0–6.2] vs. 6.1 [IQR: 5.1–7.3] in cACLD; p < 0.001). Significant correlations were found between zinc/selenium levels and MELD (zinc: ρ = -0.498, p < 0.001; selenium: ρ = -0.295, p < 0.001), HVPG (zinc: ρ = -0.400, p < 0.001; selenium: ρ = -0.157, p = 0.006), and mechanisms driving liver disease (IL6, bile-acid homeostasis). In multivariable analysis, low zinc/selenium levels, age, and MELD remained independently associated with LRE. Zinc and selenium deficiencies are common in ACLD patients, especially those with higher MELD and HVPG. Low zinc and selenium levels independently predicted hepatic decompensation and liver-related death.

Aim of the study: Malnutrition is a major factor in the causes, management, and prognosis of persistent diarrhea in young children. Besides inadequate energy intake, deficiencies of several specific nutrients have been implicated.

Results: The risk of deficiency is increased by diarrhea, which is associated with varying, and sometimes substantial, increases in zinc loss in the stool. These losses could contribute to a vicious circle, as there is now evidence that both mild and severe zinc deficiency can contribute to the duration and severity of diarrheal disease. During recovery, poor zinc status could be responsible for slow growth, especially if the recovery diet is high in phytate, a known inhibitor of zinc absorption. Research should focus on better understanding zinc metabolism and balance during diarrheal disease, the consequences of zinc deficiency, and the benefits of zinc supplementation programs.

Aim of the study: Over the past two decades, zinc has been established as essential for humans. Zinc deficiency in humans due to nutritional factors and several disease states has been recognized.

Results: The effect of zinc on protein synthesis may be due to its vital role in nucleic acid metabolism. The activity of many zinc-dependent enzymes has been shown to be adversely affected in zinc-deficient tissues. Zinc atoms in some enzyme molecules take part in catalysis and also appear to be essential for maintaining the structure of apoenzymes. Zinc also plays a role in stabilizing biomembrane structure and polynucleotide conformation. (ABSTRACT TRUNCATED AT 250 WORDS)

Aim of the study: Zinc is an essential trace element involved in a wide range of metabolic processes required for tissue growth and repair, and is also necessary for maintaining the body's defenses. Zinc deficiency can result from inadequate dietary intake, decreased intestinal absorption, and increased losses through the gastrointestinal tract, urine, and sweat.

Results: The clinical signs of zinc deficiency may be pronounced, with dermatitis, alopecia, and diarrhea; they may take the form of chronic changes such as short stature and hypogonadism; or they may be barely noticeable, with slow growth and reduced sense of taste. As with all nutritional deficiencies, the possibility must be considered before a diagnosis can be made. It is not known how severe zinc deficiency must be, or how long it must last, before the characteristic rash appears. However, since biochemical changes caused by zinc deficiency occur before any clinical changes, metabolic processes are likely to be affected before the rash signals the presence of zinc deficiency.

Aim of the study: Zinc is an essential micronutrient involved in many physiological processes in the human body, including immune system regulation, cell survival, neurological function, and red blood cell production. Zinc deficiency can lead to a wide range of clinical effects, including impaired immune function, skin problems, and reduced growth.

Results: It also outlines groups at increased risk of zinc deficiency, including patients with chronic kidney disease, sickle cell disease, malabsorption disorders, long-term proton pump inhibitor use, and older adults. Emerging evidence suggests that anemia associated with zinc deficiency may be a potentially treatable contributing factor in anemia among some at-risk groups, although the strength of the evidence varies across clinical settings and study designs. Zinc status may be assessed in patients with unexplained or treatment-resistant anemia and additional risk factors for deficiency. Further prospective studies are needed to clarify the role of zinc deficiency in anemia and define appropriate screening, supplementation, and monitoring strategies.