Age-Based Differences in Hair Zinc of Vancouver Preschoolers

Abstract

Marginal zinc deficiency (MZD), the subclinical stage of zinc deficiency, is common in industrialized societies. Serum zinc, the most common biomarker of zinc status, lacks sensitivity and specificity to diagnose this deficiency. Hair zinc, however, is sensitive and specific enough to detect MZD in children. Differences in hair zinc associated with age and sex have been reported. These differences have not been investigated thoroughly; therefore, interpretation of the results of hair analyses is difficult. This cross-sectional study was designed to examine the hair zinc status of a group of Vancouver preschoolers (24-71 months) and assess the age- and sex-based differences in their hair zinc. Hair samples were obtained (n = 719) and analyzed for zinc using inductively coupled plasma mass spectrometry. Our results indicated a mean hair zinc of 115 +/- 43 microg/g with 17% below the low hair zinc cutoff (70 microg/g). Boys and girls had comparable mean hair zinc, while girls had a significantly higher occurrence of low hair zinc than boys (21% vs. 12%). Children <4 years of age had significantly lower mean hair zinc and higher rate of low hair zinc compared to children > or =4. Our study provides important reference values for the hair zinc of healthy North American preschoolers.

Associations of Socio-demographic and Behavioral Variables with Hair Zinc of Vancouver Preschoolers

“…The finding by Gibson et al [4] of MZD was later confirmed through a zinc-supplementation study. In more recent years, our own study of a group of low-income preschoolers in Vancouver indicated widespread low hair zinc concentrations (unpublished data), while the citywide survey of the hair zinc status of preschoolers of Vancouver [5] indicated low hair zinc status comparable to that observed by Gibson et al At present, our knowledge of the determinants of MZD is limited. In this paper, we report associations between the socio-demographic and behavioral variables and hair zinc of Vancouver preschoolers.…”

“…We could not explain this finding given that the majority of evidence in the zinc literature suggests male children are more vulnerable to low hair zinc [3,21] and show a better response to zinc supplementation [22][23][24][25][26]. We have discussed the relationship between hair zinc in our sample and gender and age elsewhere [5].…”

“…The age-based differences observed in the hair zinc level and the occurrence of the low hair zinc has been discussed elaborately elsewhere [5].…”

Hair cortisol reflects socio-economic factors and hair zinc in preschoolers

“…Hair cortisol was assessed in relation to gender, parental income and education, family structure, ethnicity, and socioeconomic characteristics of the neighbourhood of residence. Our previous community-based survey of hair zinc, conducted among 342 children age 4–6 years in an ethnically and socioeconomically diverse urban environment (Vaghri et al, 2008, 2010), demonstrated an association between maternal education and hair zinc. Hair zinc is considered a biological marker of long-term adequate zinc nutrition; that is, children who have an inadequate zinc intake have lower hair zinc levels than children who have adequate zinc intake (Prasad, 1988).…”

Determination of Select Trace Elements in Hair of College Students in Jinzhou, China

“…Recently, the hair was chosen as a sample to study the trace elements in the human body by some researchers because the hair was obtained easier, and the trace elements were accumulated in it. In the previous works, they have researched the pollution accumulation in the environment [1][2][3][4][5][6][7][8], the environmental effects on human health [9][10][11], trace elements effects on human health [12][13][14][15][16], and the objects and results were different for the different research. Jinzhou is located at the southwest of Liaoning province in China.…”