Mother and Infant Nutrition Investigation in New Zealand (MINI Project): Protocol for an Observational Longitudinal Cohort Study

Digital tools and technologies used in food fortification: A scoping review

Food fortification (i.e., industrial fortification and biofortification) increases the micronutrient content of foods to improve population nutrition. Implementing effective fortification programs requires the generation and use of data to inform decision making. The use of digital tools and technologies (DTTs) for such purposes in broader nutrition programs is growing; however, there is limited consolidation of those used in fortification. This scoping review aimed to identify and describe DTTs used in fortification programs. We searched peer-reviewed and gray literature and conducted 17 stakeholder surveys. We then mapped DTTs identified against the fortification and nutrition data value chains. Of 11,741 articles identified, 158 met the inclusion criteria. From the included articles and stakeholder surveys, 125 DTTs were identified across three categories: software and tooling (n = 58), data and information lifecycle (n = 50), and hardware and infrastructure (n = 17). Gaps were identified in processing, post-harvest storage, aggregation, and transport nodes of the fortification value chain, and data prioritization, translation/dissemination, and decision-making nodes of the nutrition data value chain. DTTs have the potential to address challenges faced by fortification stakeholders to generate and use data to improve program decision making and nutritional impact. Further work is needed to standardize terminology, identify relevant DTTs from other sectors, and explore stakeholder needs.

Food Group Consumption and Nutrient Intake by Breastfeeding Women: Comparison to Current Dietary Guidelines and Nutrient Recommendations

BACKGROUND/OBJECTIVES

Optimal nutrition is essential for the health of breastfeeding women and their infants. This study aimed to assess food and nutrient intake and alignment with nutrition guidelines for breastfeeding women living in New Zealand.

METHODS

Seventy-six breastfeeding women were enrolled in the longitudinal Mother and Infant Nutrition Investigation study and completed a weighed four-day diet diary including supplement use at three months postpartum. The number of servings consumed for each food group were calculated based on the 2020 Eating and Activity Guidelines for New Zealand Adults. Nutrient intakes were compared to the nutrient reference values for Australia and New Zealand.

RESULTS

Overall, the percentages of women who met the recommended number of servings for fruits, vegetables, grain foods, meats and milk/milk products were 25%, 0%, 5%, 34%, and 13%, respectively. None of women met the current recommendations for all food groups. Many participants had intakes below the estimated average requirement or adequate intake and were at risk of nutrient inadequacy for vitamin E (55%), vitamin D (53%), manganese (61%), and selenium (55%).

CONCLUSIONS

Breastfeeding women had a low alignment with the current dietary guidelines and were at risk of an inadequate intake of vitamin E, D, manganese, and selenium. Research to investigate the barriers and enablers of healthy food choices is needed.

Portable X-ray fluorescence of zinc and selenium with nail clippings-Mother and Infant Nutrition Investigation (MINI)

Zinc and selenium are essential minerals for human nutrition. Reliable biomarkers of zinc status and selenium status in humans are therefore important. This work investigates a novel portable X-ray fluorescence (XRF) method with the ability to rapidly assess zinc and selenium in nail clippings. This approach used a mono-energetic X-ray beam to excite characteristic X-rays from the clippings. Nail clippings were obtained from the Mother and Infant Nutrition Investigation (MINI), a study designed to assess nutrition in a population of women and their breastfed children in New Zealand. Twenty mother-infant pairings were selected to provide nail clippings at two time points (visit 1 at 3 months postpartum; visit 2 at 6 months postpartum). Nail clippings from each mother-infant pairing were divided into three groupings of clippings prior to analysis: those obtained from a big toe of the mother, those from the other toes of the mother, and those from the toes and fingers of the infant. Clippings were prepared and mounted prior to XRF measurement, providing four distinct fragments from each clipping grouping. These fragments were assessed by XRF using a measurement time of either 300 s (visit 1) or 180 s (visit 2). XRF results were determined through both an automated system output and an analysis of the X-ray energy spectrum. Following this assessment of zinc and selenium with the non-destructive XRF method, clippings were measured for zinc and selenium concentration using a "gold standard" technique of inductively coupled plasma mass spectrometry (ICP-MS). Mean ICP-MS concentrations ranged from 122 μg/g to 127 μg/g for zinc, and from 0.646 μg/g to 0.659 μg/g for selenium. Precision, assessed by a relative standard deviation of measurement, was superior for ICP-MS relative to XRF. For both zinc and selenium, XRF results were compared with ICP-MS concentrations. Linear equations of best fit were determined for each comparison between XRF and ICP-MS results. Coefficients of determination (r2) were stronger for zinc (from 0.74 to 0.95) than selenium (from 0.53 to 0.70). A decrease in XRF measurement time from 300 s to 180 s did not appear to adversely affect the correlation between XRF and ICP-MS results. Using the mono-energetic portable XRF method, the correlation of XRF zinc results with ICP-MS zinc concentrations was improved over previous findings, and selenium measurement was reported for the first time. The method may prove useful for future applications to trace element analysis using nail clippings as a biomarker.

Prevalence of thyroid dysfunction in postpartum women with suboptimal iodine and selenium and adequate iron status

OBJECTIVE

Postpartum women experience thyroid dysfunction at twice the prevalence of the general population. Adequate biosynthesis of thyroid hormones depends on three trace elements: iodine, selenium and iron. This study aimed to investigate thyroid dysfunction within a cohort of women at six months postpartum in relation to iodine, selenium and iron status.

DESIGN

This cross-sectional study was part of an observational longitudinal cohort Mother and Infant Nutrition Investigation; data obtained at six months postpartum are reported.

SUBJECTS

Mother-infant pairs (n = 87) were recruited at three months postpartum and followed up at six months postpartum (n = 78).

MEASUREMENTS

Thyroid hormones (free triiodothyronine, free thyroxine, thyroid-stimulating hormone) and thyroid peroxidase antibodies were measured. Urinary iodine concentration, breast milk iodine concentration, serum thyroglobulin, plasma selenium, serum ferritin and serum soluble transferrin receptors were determined. Nonparametric data were expressed as median (25th, 75th percentile).

RESULTS

Thyroid dysfunction was found in 18% of women, and 4% of women had iron deficiency. Median urinary iodine concentration was 85 (43, 134) µg/L, median breast milk iodine concentration was 59 (39, 109) µg/L, and median serum thyroglobulin at 11.4 (8.6, 18.6) µg/L, indicating iodine deficiency. Median plasma selenium concentration was 105.8 (95.6, 115.3) µg/L. Women with marginally lower plasma selenium concentration were 1.12% times more likely to have abnormal TSH concentrations (p = .001).

CONCLUSIONS

There was a high prevalence of thyroid dysfunction. Plasma selenium concentration was the only significant predictor of the likelihood that women had thyroid dysfunction within this cohort, who were iodine deficient and mostly had adequate iron status. Strategies are required to improve both iodine and selenium status to better support maternal thyroid function.

Use of Iodine Supplements by Breastfeeding Mothers Is Associated with Better Maternal and Infant Iodine Status

Adequate iodine status during conception, pregnancy and lactation is essential for supporting infant neurodevelopment. Iodine status in adults and children was improved after two New Zealand government initiatives, but the status of breastfeeding women is unknown. This study aimed to investigate the iodine intake and status of lactating mother-infant pairs at 3 months postpartum and to assess maternal iodine knowledge and practice. Iodine intake was estimated by a weighed 4-day diet diary (4DDD). Maternal urinary iodine concentrations (UIC) in spot urine, breast milk iodine concentrations (BMIC) and infant UIC were measured. Questions about iodine-specific knowledge and practice were asked. In 87 breastfeeding mother-infant pairs, maternal iodine intake was 151 (99, 285) μg/day, and 58% had an intake below the estimated average requirement (EAR) of 190 μg/day. Maternal median UIC (MUIC) was 82 (46, 157) μg/L indicating iodine deficiency (i.e., < 100 μg/L). Women who used iodine-containing supplements had a significantly higher MUIC (111 vs 68 μg/L, P = 0.023) and BMIC (84 vs 62 μg/L, P < 0.001) than non-users. Infants fed by women using iodine-containing supplements had a higher MUIC (150 vs 86 μg/L, P = 0.036) than those of non-users. A total of 66% (57/87) of women had no or low iodine knowledge. The iodine knowledge score was a statistically significant predictor of consuming iodine-containing supplements [(beta = 1.321, P = 0.008)]. Despite a decade of initiatives to increase iodine intakes in New Zealand, iodine knowledge was low; iodine intake and status of these lactating women were suboptimal, but women who used iodine-containing supplement were more likely to achieve adequate status.Study Registration Number (Australia and New Zealand Clinical Trials Registry): ACTRN12615001028594.

Iodine status of postpartum women and their infants aged 3, 6 and 12 months: Mother and Infant Nutrition Investigation (MINI)

To alleviate the re-emergence of iodine deficiency in New Zealand, two strategies, the mandatory fortification of bread with iodised salt (2009) and a government-subsidised iodine supplement for breast-feeding women (2010), were introduced. Few studies have investigated mother and infant iodine status during the first postpartum year; this study aimed to describe iodine status of mothers and infants at 3, 6 and 12 months postpartum (3MPP, 6MPP and 12MPP, respectively). Partitioning of iodine excretion between urine and breast milk of exclusive breast-feeding (EBF) women at 3MPP was determined. In total, eighty-seven mother-infant pairs participated in the study. Maternal and infant spot urinary iodine concentration (UIC) and breast milk iodine concentration (BMIC) were determined. The percentage of women who took iodine-containing supplements decreased from 46 % at 3MPP to 6 % at 12MPP. Maternal median UIC (MUIC) at 3MPP (82 (46, 157) µg/l), 6MPP (85 (43, 134) µg/l) and 12MPP (95 (51, 169) µg/l) were <100 µg/l. The use of iodine-containing supplements increased MUIC and BMIC only at 3MPP. Median BMIC at all time points were below 75 µg/l. Infant MUIC at 3MPP (115 (69, 182) µg/l) and 6MPP (120 (60, 196) µg/l) were below 125 µg/l. Among EBF women at 3MPP, an increased partitioning of iodine into breast milk (highest proportion 60 %) was shown at lower iodine intakes, along with a reduced fractional iodine excretion in urine (lowest proportion 40 %), indicating a protective mechanism for breastfed infants' iodine status. In conclusion, this cohort of postpartum women was iodine-deficient. Iodine status of their breastfed infants was suboptimal. Lactating women who do not consume iodine-rich foods and those who become pregnant again should take iodine-containing supplements.