Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans (original) (raw)
Related papers
International Journal for Vitamin and Nutrition Research, 2007
As the current nutritional zinc intake frequently falls outside the Dietary Reference Intake (DRI) and as zinc is an essential trace mineral involved in the function of many enzymes, zinc supplementation has been recommended to prevent or treat the adverse effects of zinc deficiency. The aim of the present study was to compare the oral bioavailability of zinc bis-glycinate (a new formulation) with zinc gluconate (reference formulation). A randomized, cross-over study was conducted in 12 female volunteers. The two products were administrated orally at the single dose of 15 mg (7.5 mg × 2), with a 7-day wash-out period between the two tests. Serum concentrations of zinc were assayed by a validated inductively coupled plasma optical emission spectrometry (ICP-OES) method and Cmax, Tmax, and areas-under-the-curve (AUCs) were determined. The comparison between the two treatments was performed by comparing the Cmax, AUCt, and AUCinf using an analysis of variance followed by the calculation of the 90% confidence intervals of the ratio test/reference. Bis-glycinate administration was safe and well tolerated and bis-glycinate significantly increased the oral bioavailability of zinc (+43.4%) compared with the gluconate.
Effects of oral zinc loading on zinc metabolism in humans—I: Experimental studies
Metabolism, 1982
The effects of oral zinc on distribution, retention and excretion of orally administered '%I were studied in 56 patients with taste and smell dysfunction. The study was conducted in three phases. In the first phase all patients were studied for 21 days after receiving 3-18 &i of %n as ZnCI, orally after an overnight fast. In the second phase, started after 21 days and continued for 290 to 446 (mean 338) days, all 56 patients received placebo for Zn80,. In the third phase 14 patients continued on placebo while 38 received ZnSO, (1 Wmg/day Znf + 1 for 112 to 440 (mean 307) days. Phases two and three were a controlled clinical trial of the effects of zinc on retention of "Zn tracer. Total body retention and activity in plasma and red blood cells were measured for all patients throughout the study. Ten of the 38 patients treated with ZnSO., had additional measurements of 66Zn activity in liver and thigh made using external detectors. Total body retention during the second phase placebo period was not significantly different (p > 0.25) for the 36 subjects subsequently treated with ZnSO, (biological half-time (T,) 378 + 12 days) (mean + SEMI and the 14 who were continued on placebo through the third phase of the study (T, = 384 + 8 days). During the third phase patients receiving ZnSO, showed an accelerated loss of total body "Zn (T, = 235 f 8 days) which was significantly different (p < 0.001) from half-time values during placebo treatment. Accelerated loss of "Zn from the thigh was apparent immediately, while that from the liver began after a mean delay of 107 days. There was no apparent effect of zinc on loss of mean =Zn activity from red blood cells.
Journal of Nutrition, 2014
The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67 Zn and 70 Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design.
European Journal of Drug Metabolism and Pharmacokinetics, 1982
In this study the authors compared the pharmacokinetics of three zinc salts after parenteral and oral administration to rabbits: zinc sulfate, a soluble mineral salt; zinc pantothenate, a soluble organic salt; and zinc orotate, an insoluble organic salt. The results obtained with the two soluble salts were not significantly different (p < 0.05). Therefore they appear to be bioequivalent. The plasma concentration curve for zinc orotate shows a faster distribution (a) and elimination phase (fl) after parenteral administration, and a slower absorption phase (Ka) after oral administration, when compared with that of the other two salts. It was shown that the dissolution behaviour of these zinc salts in water does not correlate with the parameters found in vivo.
Zinc bioavailability and homeostasis
The American Journal of Clinical Nutrition, 2010
Zinc has earned recognition recently as a micronutrient of outstanding and diverse biological, clinical, and global public health importance. Regulation of absorption by zinc transporters in the enterocyte, together with saturation kinetics of the absorption process into and across the enterocyte, are the principal means by which whole-body zinc homeostasis is maintained. Several physiologic factors, most notably the quantity of zinc ingested, determine the quantity of zinc absorbed and the efficiency of absorption. Other factors are age and the time over which zinc is ingested. Zinc from supplements has not been shown to be absorbed differently from that taken with meals that lack inhibitors of zinc absorption. The principal dietary factor known to impair zinc bioavailability is inositol hexa-(and penta-) phosphate or phytate. Modeling of zinc absorption as a function of dietary zinc and phytate accounts for .80% of the variability in the quantity of zinc absorbed. Fitting the model to new data has resulted in continual improvement in parameter estimates, which currently indicate a maximal absorption in adults of '6 mg Zn/d and that the average estimated dietary requirement doubles with 1000 mg dietary phytate/d. Intestinal excretion of endogenous zinc is regulated in response to recent absorption and to zinc status. The quantitative relation of intestinal excretion of endogenous zinc to zinc absorption is currently considered to be of major importance in the determination of zinc requirements. The effects of phytate on intestinal losses of endogenous zinc merit further investigation but are probably not of the same magnitude as its inhibitory effects on absorption of exogenous zinc.
The American journal of clinical nutrition, 2008
No studies have examined the independent effects of current and longer-term dietary zinc intakes on zinc absorption. We determined the effects of current compared with longer-term zinc intake on fractional zinc absorption (FZA). We studied 9 men whose usual zinc intakes were >11 mg/d. FZA was measured at baseline, depletion (0.6 mg Zn/d for 1 wk and 4 mg Zn/d for 5 wk), and repletion (11 mg Zn/d for 4 wk with 20 mg supplemental Zn/d for first 7 d). During 2 successive days after each dietary period, subjects consumed either adequate-zinc meals (11 mg Zn/d) with a zinc stable isotope tracer for 1 d, followed by low-zinc meals (4 mg Zn/d) with zinc tracer, or vice versa. Five days after oral dosing, a zinc tracer was infused intravenously. FZA was measured with the use of a modified double isotope tracer ratio method with urine samples collected on days 5-7 and 10-12 of absorption studies. Plasma and urinary zinc did not vary by dietary period. Mean FZA was greater from low-zinc me...
Experimental Gerontology, 2008
Zinc is a nutritionally essential trace element, and thus zinc deficiency may severely affect human health. Many studies were published in which the effect of nutritional zinc supplementation on the incidence or severity of a certain disease was investigated. This review summarizes the main observations and aims to evaluate the use of nutritional zinc supplementation for prevention and treatment of human disease.
Zinc absorption as a function of the dose of zinc sulfate in aqueous solution
American Journal of Clinical Nutrition, 2005
Background: Zinc supplements are used extensively in medicine and research and for public health purposes in the prevention and treatment of zinc deficiency. However, little is known about the efficiency of zinc utilization after different doses. Objective: The objective was to determine the relation between dose of aqueous zinc and absorbed zinc (AZ) in healthy adults. Design: Eight healthy adults (3 men and 5 women) aged 33.8 Ȁ 9.8 y (x Ȁ SD) received 3 pairs of zinc doses (2 and 5, 10 and 15, and 20 and 30 mg) in random order in 3 phases (1 pair per phase). There was a 3-wk washout between phases. Aqueous zinc sulfate labeled with 70 Zn or 68 Zn was orally administered in the postabsorptive state on days 1 and 6, respectively; intravenous 67 Zn was administered 1 h after the first oral zinc dose. Two urine samples were collected daily from days 3 to 15; zinc isotopic ratios were determined by inductively coupled plasma mass spectrometry. Fractional absorption of zinc (FAZ) was determined by dual-isotope-tracer ratio; AZ was calculated by multiplying FAZ by dose. Results: Mean (ȀSD) AZ values at doses of 2.2, 5.2, 10.4, 15.2, 20.3, and 30.1 mg ingested Zn were 1.6 Ȁ 0.4, 3.5 Ȁ 1.3, 7.4 Ȁ 1.0, 9.5 Ȁ 2.2, 11.0 Ȁ 4.4, and 11.2 Ȁ 2.1 mg, respectively. A saturable dose-response model, the Hill equation, was selected to model the relation of AZ to ingested zinc. Parameter estimation by nonlinear regression predicted a maximum zinc absorption of 13 mg for larger doses. Conclusions: Increases in aqueous zinc doses 20 mg result in relatively small and progressively diminishing increases in AZ postabsorptively in healthy adults.
Biological trace element research
Zinc absorption may be estimated by measuring the area under the plasma zinc curve following the ingestion of a zinc supplement. The aim of this study is to determine the reproducibility of such a response when a small dose of zinc is administered to healthy volunteers. Five female subjects were asked to consume 4.5 mg elemental zinc, and blood samples were obtained at 30 min intervals for 5 h. The experiment was repeated in the same volunteers 12-16 d later. The area under the plasma zinc curve was 30% lower after the second zinc tolerance test compared with the first (11.0 vs 15.8 mumol/l h). This difference could not be explained by differences in the fasting plasma zinc levels (12.9 mumol/L Experiment one, 15.1 mumol/L Experiment 2) nor was it related to technical or clinical parameters. The area under the curve after 5 h was strongly correlated with the response after 4 h. Hence we conclude that a small dose of zinc can be used to determine zinc absorption and a shorter experim...
Biological Trace Element Research, 1992
The absorption and metabolism of zinc in a commercial form for oral use (RubozinC ~, 15 mg zinc as gluconate) were investigated in 10 subjects by a kinetic study of the serum zinc profile after administration of 45 mg zinc under three conditions: after an overnight fast, during a standardized breakfast, and 2 h after this meal. The pharmacokinetic parameters were calculated by a method suitable to the characterization of rebound effects (recycling of the element in the gastrointestinal tract). In fasting state, the parameters were comparable to those previously collected in the same subiects with oral 45 mg zinc as sulfate, except with very significantly higher C ...... and area under curve (AUC), showing a better bioavailability for zinc in the commercial form. The light meal perturbed the absorption process as evidenced by the significant increases in the lag time (+ 180%), the *Author to whom all correspondence and reprint requests should be addressed.