Dual fortification of salt with iron and iodine in women and children in rural Ghana.

OBJECTIVE: To test the efficacy of double-fortified salt (DFS) on the anaemia and iodine deficiency (ID) status of women and their children. DESIGN: Double-blind randomised controlled trial. SETTING: Sekyere West District of Ghana. SUBJECTS: In this eight-month trial, mildly anaemic or non-anaemic, non-pregnant, non-lactating women were randomised into three groups receiving: DFS plus weekly placebo (n = 61); iodised salt plus weekly 70 mg iron supplement (n = 65); or iodised salt (IS) plus weekly placebo (control group, n = 58). Correspondingly, their mildly anaemic and non-anaemic children aged 1-5 years were randomised into two groups receiving either the DFS (n = 23) or IS alone (control group, n = 59). RESULTS: At the end of the intervention, prevalence of anaemia in women remained unchanged in the DFS or IS plus weekly iron supplement group, but significantly increased by 19.5% in the control group (P = 0.039). In children, prevalence of anaemia in the DFS group significantly decreased by 21.7% (P = 0.025) while no change was observed in the control group. ID decreased significantly in all groups of women (P < 0.001) and children (P < 0.05), with no difference among groups of women and children. CONCLUSION: While the use of DFS prevented anaemia in women, it had a significant role in both the prevention and treatment of anaemia in children. Both the DFS and IS significantly reduced ID in women and children to a similar degree.

Inter-relationships between DNA damage, ascorbic acid and glycaemic control in Type 2 diabetes mellitus.

AIMS: The onset of complications in Type 2 diabetes mellitus (DM) patients cannot be predicted in individuals. Evidence suggests a link between complications and hyperglycaemia, oxidative stress and antioxidants, but causality is unclear. This study investigated baseline (entry) fasting plasma ascorbic acid, lymphocytic DNA damage and glycaemic control in Type 2 DM as part of a long-term study, the aim of which is to explore a biomarker profiling approach to identify and improve outcome in high-risk subjects. METHODS: A cross-sectional study, in which DNA damage, glycated haemoglobin (HbA(1c)), fasting plasma glucose (FPG) and ascorbic acid (AA) were measured on fasting blood samples collected from 427 Type 2 DM subjects. RESULTS: DNA damage was significantly (P < 0.0001) and directly correlated to both FPG (r = 0.540) and HbA(1c) (r = 0.282), and was significantly (P < 0.0001), independently and inversely correlated to plasma AA (r = -0.449). In those subjects with both poor glycaemic control and low AA (< 48 microm, the overall mean value for the study group), DNA damage was significantly (P < 0.005) higher compared with those subjects with a similar degree of hyperglycaemia but with AA above the mean. CONCLUSIONS: The novel finding of a significant inverse relationship between plasma AA and DNA damage in Type 2 DM indicates that poorly controlled diabetic subjects might benefit from increased dietary vitamin C. The data also have important implications for biomarker profiling to identify those subjects who might benefit most from intensive therapy. Longer-term follow-up is underway.

Fractional zinc absorption using a single isotope tracer.

BACKGROUND: Fractional absorption of zinc (Zn) has been measured using dual isotopes of Zn given simultaneously. An oral test dose and an intravenous (i.v.) reference dose are administered, followed by the measurement of the double isotopic enrichment (E) in urine 48 h after administration. We postulated that an estimate of the %E in urine for a given i.v. dose of Zn may be used to eliminate the need for venipuncture and the second Zn isotope. OBJECTIVES: To determine a constant (k) for the Zn enrichment of urine after i.v. administration of a dose of labeled Zn in Zn-replete subjects. To use 'k' to calculate fractional absorption of Zn, and to compare these values to values obtained using the standard dual isotope method. DESIGN: Single-arm cohort. SETTING: The Hospital for Sick Children, Toronto, Canada. SUBJECTS: Twenty-three healthy adults were recruited from the Metropolitan Toronto area. Seventeen subjects completed the study. INTERVENTIONS: A 2.29 mg i.v. dose of (67)Zn followed immediately by a 2.50 mg oral dose of (70)Zn. RESULTS: Population mean percentage enrichment (%E) of (67)Zn in urine was 1.43 (95% CI 1.26, 1.60). The ratio of the i.v. dose to mean %E in urine (k) was estimated to be 1.60 mg (95% CI 1.43, 1.82). There was no difference in the mean fractional absorption of Zn calculated using the single compared to the dual isotope method: 12.58% (95% CI 2.22, 22.94) vs 12.68% (95% CI 4.52, 20.85), respectively (P=0.89). The correlation coefficient between the two methods was 0.81 (P<0.0001). CONCLUSIONS: The dual isotope method may be replaced by using a constant (k) and a single oral dose of isotopic-enriched Zn to estimate fractional absorption of Zn within a population. SPONSORSHIP: Gerber Products Company, Fremont, MI.

Efficacy of meat and iron-fortified commercial cereal to prevent iron depletion in cow milk-fed infants 6 to 12 months of age: a randomized controlled trial.

OBJECTIVE: To determine whether utilization of iron from infant cereal and pureed meat was sufficient to prevent iron depletion and/or anaemia in infants 6 to 12 months old fed whole cow milk (WCM) as their primary milk source. DESIGN: Six-month-old infants were randomized into a treatment group (n = 43) receiving iron-fortified infant cereal (10.2 mg iron), pureed meat (0.75-1.7 mg iron) and WCM for six months or a control group (n = 54) receiving no dietary intervention. Haemoglobin < 110 g/L or ferritin < 10 micrograms/L (measured bi-monthly), confirmed in a second blood sample, defined end-points. RESULTS: Proportion reaching end-point was similar between the treatment (3/43) and control infants (5/54) (p = 0.66). Infants not complying with the protocol were at greater risk of reaching end-point (p = 0.0002). Change in haemoglobin and ferritin across age was similar in both groups. CONCLUSIONS: Iron deficiency is not a concern in WCM-fed infants after six months of age if iron-containing complementary foods are concurrently ingested.

Disparity of serum transferrin receptor measurements among different assay methods.

OBJECTIVE: To highlight differences in the quantification of transferrin receptor (TfR) concentration (a reliable index of iron deficiency) between three different assay methods. DESIGN: Methods comparison of TfR measurements in 'elevated' and 'normal' human sera using the Ramco, Quantikine and 'Lab' assays. SETTING: The Hospital for Sick Children, Toronto, Ontario, Canada. SUBJECTS: Pooled TfR for elevated and normal human sera obtained from the Ramco TfR assay kit. MAIN OUTCOME MEASURES: Differences between TfR concentrations in normal and elevated samples and repeatability for each assay method and limits of agreement in TfR quantification between assay methods. RESULTS: The mean TfR concentrations for the elevated reference serum samples was higher than the normal reference samples within each individual assay (P < 0.001); however, measurement agreement between methods was poor. CONCLUSIONS: Recognition of the relative differences in the values obtained from each of the assays should affect the interpretation of TfR concentration as an index of iron deficiency.

Percentile estimates for transferrin receptor in normal infants 9-15 mo of age.

To establish percentile estimates of transferrin receptor (TfR) for healthy infants, plasma TfR was measured in 485 healthy infants 9-15 mo of age from Edmonton, Toronto, Montreal, and Halifax. Education and income of the sample families were reflective of the average family based on the 1991 census estimates. The mean (+/-SD) plasma TfR concentration was 4.4 +/- 1.1 mg/L. As expected in the infant population, there were no differences in TfR concentrations as a result of sex, and within this small age range there was no significant change across age. Furthermore, the TfR concentration in plasma was not associated with hemoglobin, serum ferritin, or free erythrocyte protoporphyrin. TfR has been shown to be a sensitive, quantitative measure of tissue iron deficiency not affected by inflammation and is potentially important in the diagnosis of iron deficiency, but there is a lack of normative data, particularly in infants, who are at highest risk of iron deficiency. If TfR proves useful in the diagnosis of iron deficiency, the current data will be useful as a reference standard for healthy infants.