Risk Of Zinc Deficiency Research Articles

Suggested lower cutoffs of serum zinc concentrations for assessing zinc status: reanalysis of the second National Health and Nutrition Examination Survey data (1976–1980)

The risk of zinc deficiency in populations can be estimated by comparing serum zinc data with statistically defined lower cutoffs derived from a presumably healthy population. Serum zinc data are available from a large sample of the US population assessed during the second National Health and Nutrition Examination Survey (NHANES II). Although the original analysis of these data considered fasting status and the time of day of blood sampling, it did not account for potentially confounding variables that may affect the serum zinc concentration, such as age, sex, and health status. The objective was to describe variations in serum zinc concentration by age, sex, and other characteristics and to recommend lower cutoffs for presumably healthy persons. Serum zinc data from NHANES II were analyzed by using analysis of variance and covariance models to identify and describe variables significantly associated with serum zinc concentration; 2.5th percentile curves were produced and used to establish age- and sex-based lower cutoffs. Age and sex were significant confounders of serum zinc concentration, so separate lower cutoffs were derived for children and adolescent and adult males and females. Other minor confounding variables were identified. Tentative lower cutoffs for pregnancy and oral contraceptive use were also derived. The interpretation of population serum zinc data with the use of lower cutoffs should account for the age and sex of the subjects, pregnancy and oral contraceptive use, and fasting status and time of day of blood collection.

Zinc kinetics in insulin-dependent diabetes mellitus patients.

Zinc has an important role in the control of carbohydrate metabolism, and diabetic patients are at risk for zinc deficiency. However, there are conflicting data concerning nutritional zinc status. In order to investigate this topic, 10 normal and 10 insulin-dependent diabetic patients were studied following venous zinc tolerance test. Our results found no evidence of zinc deficiency or of changes on the kinetic parameters of zinc in patients with insulin-dependent diabetes mellitus following a venous zinc tolerance test.

Evaluation of zinc metabolism with use of stable-isotope techniques: implications for the assessment of zinc status

Zinc stable isotopes can be applied to the identification of populations at risk for zinc deficiency and to moni-toring the effects of zinc intervention studies designed to improve zinc nutriture. Techniques using these isotopes can provide information on how effectively the intestine is absorbing exogenous dietary zinc and conserving endogenous zinc. They can also yield estimates of the quantity of readily exchangeable zinc in the body. Data derived from stable-isotope studies can provide extensive information on zinc status and the bioavailability of dietary zinc, allowing researchers to relate zinc intake to physiologic and pathologic conditions. Application of these techniques in longitudinal studies can provide quantitative data on the effectiveness of prevention programs such as simple community measures aimed at reducing dietary phytate and zinc fortification and supplementation programs. Further, judicious application of zinc stable-isotope techniques could make an important contribution to progress toward the eradication of zinc deficiency in infants and young children in the developing world. Am J Clin Nutr 1998(suppl);68:410S–3S.

Dietary zinc intake of vegetarian and nonvegetarian patients with anorexia nervosa.

Anorexia nervosa (AN) and zinc deficiency, found most frequently in young females, have a number of symptoms in common. These include weight loss, alterations in taste and appetite, depression, and amenorrhea. Approximately half of anorexia nervosa patients (ANs) are vegetarian (VANs), a practice that may increase their risk for zinc deficiency. This study compared the dietary intake of zinc and related nutrients in 9 outpatient VANs with that of 11 outpatient nonvegetarian patients with anorexia nervosa (NVANs). VANs reported significantly lower (p < .05) dietary intakes of zinc, fat, and protein, and a significantly higher (p < .05) intake of calories from carbohydrates than NVANs. There were no significant differences between the groups in dietary intake of calories, calcium, copper, iron, or magnesium. These findings indicate that zinc intake should be routinely assessed in VANs and that zinc supplementation of their diets may be indicated.

Zinc deficiency in anorexia nervosa

Adolescents with anorexia nervosa were evaluated for clinical and biochemical evidence of zinc deiciency. To assess whether these patients would benefit from zinc supplementation, a double-blind, randomized, controlled trial was conducted. The mean zinc intake of the anorexic group calculated on the basis of three-day dietary records was 7.7 ± 5.2 mg/day, which is significantly below the recommended daily allowance of 15 mg for adolescents ( p < 0.001). The mean urinary zinc excretion in the anorexic group was 257.1 ± 212.7 μg/24 hours compared to 749.9 ± 897.8 μg/24 hours in the control group ( p < 0.005), This result suggests that the zinc status of anorexia nervosa patients may be compromised due to an inadequate zinc intake. Zinc supplementation (50 mg elemental zinc/day) was followed by a decrease in the level of depression and anxiety as assessed by the Zung Depression Scale ( p < 0.05) and the State-Trait Anxiety Inventory ( P < 0.05), respectively. Our data suggest that individuals with anorexia nervosa may be at risk for zinc deficiency and may respond favorably after zinc supplementation.

Zinc and copper status of allergic children.

Zinc and copper status was examined in 19 healthy and 43 atopic children (22 asthmatics and 21 eczematous) 2-14 years old. Dietary intakes for energy, protein, zinc and copper and some nutritional indices (height, weight, serum protein, albumin, ceruloplasmin) were similar in the allergic and in the control group. The proton-induced X-ray fluorescence technique was used to assess zinc and copper concentrations in serum and hair. No difference was detected in serum zinc concentration between allergic and healthy children. In contrast, mean hair zinc level was lower (p less than 0.05) in allergic than in healthy children (99 +/- 6 vs. 147 +/- 9 micrograms/g). Mean serum copper content was higher in asthmatic than in control children while mean hair copper was higher (p less than 0.05) in asthmatic and eczematous children than in the control group. These findings suggest a different zinc and copper nutritional status between allergic and healthy subjects. Allergic children, in particular, seem to be a risk of zinc deficiency.

Assessment of the zinc nutritional status of selected elderly subjects

Elderly participants (with a mean age range of 71 to 75 years) residing in two housing complexes in Tuscaloosa, Alabama, can generally be characterized as predominantly women with a low socioeconomic status living alone. A majority of the participants consumed less than the RDA for food energy. The protein intake was nearly equal to or exceeded the RDA; however, the mean intake of zinc was only half of the RDA. The mean hair zinc concentration of the participants corresponded with the levels reported for this age group by other researchers. Their mean taste thresholds were higher (lower taste acuity) than those reported for young adults. Detection thresholds decreased as the ages of the participants increased. The taste acuity of the participants resembled that of groups of elderly studied by other investigators. A precise definition of low zinc status measurements among the elderly is not available at this time. However, the low hair zinc concentrations and taste acuity, compounded with the low zinc intake, indicate that this population is at risk for zinc deficiency.