Dynamic Gastrointestinal Digestion of Bovine, Caprine and Ovine Milk Reconstituted from Commercial Whole Milk Powders.

The global dairy market has been increasingly diversified with more dairy product offerings of milk products from different animal species. Meanwhile, milk powders remain the main exported dairy product format due to their ease of transportation. In this work, we studied the structural changes, protein hydrolysis and nutrient delivery during dynamic gastric digestion and small intestinal digestion of cow, goat and sheep milk reconstituted from commercial whole milk powders. The results show that the reconstituted milks digest similarly to processed fresh milk. The digestion behaviors of the three reconstituted ruminant milks are broadly similar (gastric coagulation, kinetics of gastric emptying of protein and fat and the high digestibility in the small intestine) with some differences, which are likely contributed by the processing history of the milk powders. The delivery of individual amino acids to the small intestine differed between the early and late stages of gastric digestion, which were primarily affected by the abundance of amino acids in caseins and whey proteins but also by the difference between milk types associated with their gastric coagulation behaviors. This work showed that powdered milk is similar to fresh processed milk in digestion behavior, and the inherent differences between ruminant milks can be modified by processing treatments.

Comparing two simplified questionnaire-based methods with 24-h recalls for estimating fortifiable wheat flour and oil consumption in Mandaluyong City, Philippines.

Information on fortifiable food consumption is essential to design, monitor and evaluate fortification programmes, yet detailed methods like 24-h recalls (24HRs) that provide such data are rarely conducted. Simplified questionnaire-based methods exist but their validity compared with 24HRs has not been shown. We compared two simplified methods (i.e., a household food acquisition and purchase questionnaire [FAPQ] and a 7-day semiquantitative food frequency questionnaire [SQ-FFQ]) against 24HRs for estimating fortifiable food consumption. We assessed the consumption of fortifiable wheat flour and oil using a FAPQ and, for wheat flour only, a 7-day SQ-FFQ and compared the results against 24HRs. The participants included children 12-18 months (n = 123) and their mothers 18-49 years selected for a study assessing child vitamin A intake and status in Mandaluyong City, Philippines. For fortifiable wheat flour, the FAPQ estimated considerably lower mean intakes compared to 24HRs for children and mothers (2.2 vs. 14.1 g/day and 5.1 vs. 42.3 g/day, respectively), while the SQ-FFQ estimated slightly higher mean intakes (15.7 vs. 14.1 g/day and 51.5 vs. 42.3 g/day, respectively). For fortifiable oil, the FAPQ estimated considerably higher mean intakes compared to 24HRs for children and mothers (4.6 vs. 1.8 g/day and 12.5 vs. 6.1 g/day, respectively). The SQ-FFQ, but not the FAPQ, generated useful information on fortifiable food consumption that can inform fortification programme design and monitoring decisions in the absence of more detailed individual-level data. Potential adaptations to improve the FAPQ, such as additional questions on foods prepared away from home and usage patterns, merit further research.

Filipino Children with High Usual Vitamin A Intakes and Exposure to Multiple Sources of Vitamin A Have Elevated Total Body Stores of Vitamin A But Do Not Show Clear Evidence of Vitamin A Toxicity.

Background: Young children exposed to high-dose vitamin A supplements (VAS) and vitamin A (VA)-fortified foods may be at risk of high VA intake and high VA total body stores (TBS). Objectives: TBS and estimated liver VA concentration were compared among children with adequate or high VA intake and different timing of exposure to VAS, and associations between estimated liver VA concentrations and biomarkers of VA toxicity were examined. Methods: Children 12-18 mo of age (n = 123) were selected for 3 groups: 1) retinol intake >600 µg/d and VAS within the past mo, 2) retinol intake >600 µg/d and VAS in the past 3-6 mo, and 3) VA intake 200-500 µg retinol activity equivalents (RAE)/d and VAS in the past 3-6 mo. Dietary intake data were collected to measure VA intakes from complementary foods, breast milk, and low-dose, over-the-counter supplements. TBS were assessed by retinol isotope dilution, and VA toxicity biomarkers were measured. Main outcomes were compared by group. Results: Mean (95% CI) VA intakes excluding VAS were 1184 (942, 1426), 980 (772, 1187), and 627 (530, 724) µg RAE/d, in groups 1-3, respectively; mean VA intake was higher in groups 1 and 2 compared with group 3 (P < 0.05). Geometric mean (GM) (95% CI) TBS were 589 (525, 661), 493 (435, 559), and 466 (411, 528) µmol, respectively. GM TBS and GM liver VA concentrations were higher in group 1 compared with group 3 (liver VA concentration: 1.62 vs. 1.33 µmol/g; P < 0.05). Plasma retinyl ester and 4-oxo-retinoic acid concentrations and serum markers of bone turnover and liver damage did not indicate VA toxicity. Conclusions: In this sample, most children had retinol intakes above the Tolerable Upper Intake Level (UL) and liver VA concentrations above the proposed cutoff for "hypervitaminosis A" (>1 µmol/g liver). There was no evidence of chronic VA toxicity, suggesting that the liver VA cutoff value should be re-evaluated. This trial was registered at www.clinicaltrials.gov as NCT03030339.

Selenium intakes and plasma selenium of New Zealand toddlers: secondary analysis of a randomised controlled trial.

Little is known about Se intakes and status in very young New Zealand children. However, Se intakes below recommendations and lower Se status compared with international studies have been reported in New Zealand (particularly South Island) adults. The Baby-Led Introduction to SolidS (BLISS) randomised controlled trial compared a modified version of baby-led weaning (infants feed themselves rather than being spoon-fed), with traditional spoon-feeding (Control). Weighed 3-d diet records were collected and plasma Se concentration measured using inductively coupled plasma mass spectrometry (ICP-MS). In total, 101 (BLISS n 50, Control n 51) 12-month-old toddlers provided complete data. The OR of Se intakes below the estimated average requirement (EAR) was no different between BLISS and Control (OR: 0·89; 95 % CI 0·39, 2·03), and there was no difference in mean plasma Se concentration between groups (0·04 µmol/l; 95 % CI -0·03, 0·11). In an adjusted model, consuming breast milk was associated with lower plasma Se concentrations (-0·12 µmol/l; 95 % CI -0·19, -0·04). Of the food groups other than infant milk (breast milk or infant formula), 'breads and cereals' contributed the most to Se intakes (12 % of intake). In conclusion, Se intakes and plasma Se concentrations of 12-month-old New Zealand toddlers were no different between those who had followed a baby-led approach to complementary feeding and those who followed traditional spoon-feeding. However, more than half of toddlers had Se intakes below the EAR.

Multiple Micronutrients, Including Zinc, Selenium and Iron, Are Positively Associated with Anemia in New Zealand Aged Care Residents.

Anemia is a significant comorbidity for older adults not fully attributable to iron deficiency. Low-grade inflammation and other micronutrient deficiencies also contribute. This cross-sectional study examined the relationships between nutrient and non-nutrient factors with hemoglobin and anemia in 285 residents (>65 years) of 16 New Zealand aged-care facilities. Blood samples were analyzed for hemoglobin, ferritin, sTfR, hepcidin, zinc, selenium, and interleukin-6 (IL-6), (with ferritin, sTfR, zinc and selenium adjusted for inflammation). Linear regression models examined the relationships between micronutrient biomarkers (iron, zinc, selenium, vitamin B-12 and D), age, sex, and health factors with hemoglobin. Thirty-two percent of participants exhibited anemia, although <2% had either depleted iron stores or iron deficiency. Plasma zinc and selenium deficiencies were present in 72% and 38% of participants, respectively. Plasma zinc and total body iron (TBI) were positively associated (p < 0.05) with hemoglobin, while gastric acid suppressing medications, hepcidin, and interleukin-6 were inversely associated. These relationships were maintained after the application of anemia cut-offs. These findings emphasize the importance of considering multiple micronutrient deficiencies as risk factors for anemia.

Determination of Vitamin A Total Body Stores in Children from Dried Serum Spots: Application in a Low- and Middle-Income Country Community Setting.

BACKGROUND: The retinol isotope dilution (RID) method has been used to evaluate vitamin A (VA) status in healthy adults and children in low- and middle-income countries (LMIC) and to assess the efficacy of various VA interventions. OBJECTIVE: The study was designed to examine whether dried serum spots (DSS) can be applied to RID when conducting VA total body store (TBS) assessments in community settings. METHODS: Four days after an oral dose of 0.4 mg [13C10]retinyl acetate was administered to Filipino children (12-18 mo), a single blood draw was divided to isolate both serum and plasma. Serum (40 µL) was spotted and dried on Whatman 903 cards and shipped at ambient temperature whereas liquid plasma (LP) was frozen at -80°C and shipped on dry ice. The VA tracer to tracee ratio from DSS and LP was quantified by LC-MS/MS. Comparisons between DSS and LP paired samples (n = 72) were made for [13C10]retinol specific activity (SAp) by Pearson's correlation and for VA TBS by Bland-Altman analysis. RESULTS: The sum of 3 coextracted DSS were required to consistently detect [13C10]retinol above the LC-MS/MS limit of quantitation (LOQ). [13C10]retinol SAp from DSS was highly correlated with SAp from LP (r = 0.945; P < 0.01). A comparison of methods for TBS determination using Bland-Altman analysis indicated agreement with an intraindividual difference of 24.7 µmol (4.6%). Mean total liver reserve (TLR) values from DSS and LP were 1.7 µmol/g (± 0.6 SD) and 1.6 µmol/g (± 0.6 SD), respectively. CONCLUSIONS: VA TBS can be determined from DSS thereby reducing the logistics and cost of maintaining a cold chain by shipping samples at ambient temperature and, thus, making the RID technique more feasible in LMIC community settings. This trial was registered at https://clinicaltrials.gov as NCT03030339.

A comparison of methods for adjusting biomarkers of iron, zinc, and selenium status for the effect of inflammation in an older population: a case for interleukin 6.

Background: Older people are at risk of micronutrient deficiencies, which can be under- or overestimated in the presence of inflammation. Several methods have been proposed to adjust for the effect of inflammation; however, to our knowledge, none have been investigated in older adults in whom chronic inflammation is common. Objective: We investigated the influence of various inflammation-adjustment methods on micronutrient biomarkers associated with anemia in older people living in aged-care facilities in New Zealand. Design: Blood samples were collected from 289 New Zealand aged-care residents aged >65 y. Serum ferritin, soluble transferrin receptor (sTfR), total body iron (TBI), plasma zinc, and selenium as well as the inflammatory markers high-sensitivity C-reactive protein (CRP), α1-acid glycoprotein (AGP), and interleukin 6 (IL-6) were measured. Four adjustment methods were applied to micronutrient concentrations: 1) internal correction factors based on stages of inflammation defined by CRP and AGP, 2) external correction factors derived from the literature, 3) a regression correction model in which reference CRP and AGP were set to the maximum of the lowest decile, and 4) a regression correction model in which reference IL-6 was set to the maximum of the lowest decile. Results: Forty percent of participants had elevated concentrations of CRP, AGP, or both, and 37% of participants had higher than normal concentrations of IL-6. Adjusted geometric mean values for serum ferritin, sTfR, and TBI were significantly lower (P < 0.001), and plasma zinc and selenium were significantly higher (P < 0.001), than the unadjusted values regardless of the method applied. The greatest inflammation adjustment was observed with the regression correction that used IL-6. Subsequently, the prevalence of zinc and selenium deficiency decreased (-13% and -14%, respectively; P < 0.001), whereas iron deficiency remained unaffected. Conclusions: Adjustment for inflammation should be considered when evaluating micronutrient status in this aging population group; however, the approaches used require further investigation, particularly the influence of adjustment for IL-6.

Vitamin D status and its predictors in New Zealand aged-care residents eligible for a government-funded universal vitamin D supplementation programme.

OBJECTIVE: The provision of prescribed vitamin D to all aged-care residents has been implemented in New Zealand as part of a government-led falls prevention programme. To our knowledge, there has been no evaluation of this universal programme on vitamin D status and functional and health outcomes. Thus, we aimed to determine 25-hydroxyvitamin D (25(OH)D) concentrations and their predictors in aged-care residents across the country and to investigate whether the government-funded programme was associated with adequate vitamin D status. DESIGN: Cross-sectional survey of sociodemographic, biochemical, anthropometric, dietary and health characteristics. Blood samples were analysed for serum 25(OH)D and other biochemical measures. Multiple regression was used to examine predictors of vitamin D status. SETTING: Sixteen residential aged-care facilities throughout New Zealand. SUBJECTS: Residents aged ≥60 years with residency duration >12 weeks (n 309). RESULTS: Mean serum 25(OH)D was 89·9 (95 % CI 85·2, 94·5) nmol/l and monthly supplements (1250 µg (50 000 IU)) were taken by 75 % of all residents. Of those not taking a funded supplement, 65·3 % had serum 25(OH)D 125 nmol/l. CONCLUSIONS: Residents taking supplemental vitamin D had adequate vitamin D status; however monitoring of long-term supplementation should be considered, due to the high proportion of participants with high serum 25(OH)D levels.

Iodine Status of New Zealand Elderly Residents in Long-Term Residential Care.

In response to the re-emergence of iodine deficiency in New Zealand, in 2009 the government mandated that all commercially made breads be fortified with iodized salt. There has been no evaluation of the impact of the program on iodine status of the elderly, despite this population group being vulnerable to iodine deficiency or excess. The aim of this study was to describe the iodine status of elderly New Zealanders in residential aged-care homes following the implementation of the bread fortification program. A cross-sectional survey was conducted, involving 309 residents (median age 85 years) from 16 aged-care homes throughout NZ. Information on socio-demographic, anthropometric, dietary and health characteristics were collected. Casual spot urine samples were analysed for urinary iodine concentration (UIC). Blood samples were analysed for serum thyroglobulin, thyroglobulin antibodies, and other biochemical indices. The median UIC (MUIC) of the residents was 72 µg/L, indicating mild iodine deficiency, and 29% had a UIC < 50 µg/L. Median thyroglobulin concentration was 18 ng/mL and 26% had elevated thyroglobulin concentration (>40 ng/mL), suggesting iodine insufficiency. Diuretic use was associated with lower MUIC (p = 0.043). Synthetic thyroxine use was associated with lower odds of having a UIC < 50 µg/L (OR 0.32, p = 0.030)) and lower median thyroglobulin (-15.2 ng/mL, p = 0.001), compared with untreated participants. Frailty was associated with elevated thyroglobulin (p = 0.029), whereas anemia was associated with lower thyroglobulin (p = 0.016). Iodine insufficiency persists in New Zealanders residing in residential aged-care homes despite increasing iodine intake from fortified bread. Research is required to establish optimal iodine intake and status in the elderly.

Trends in serum total cholesterol and dietary fat intakes in New Zealand between 1989 and 2009.

OBJECTIVE: To describe trends in serum cholesterol and dietary fat intakes for New Zealand adults between 1989 and 2008/09. METHODS: Serum total cholesterol concentrations and dietary fat intakes were analysed for 9,346 New Zealanders aged 15-98 years (52% women) who participated in three national surveys in 1989, 1997 and 2008/09. RESULTS: Population mean serum cholesterol decreased from 6.15 mmol/L in 1989 to 5.39 mmol/L in 2008/09. Mean saturated fat intake decreased from 15.9% of energy intake in 1989 to 13.1% in 2008/09. Between 1997 and 2008/09, unsaturated fat intake increased and fat from butter and milk decreased. Older adults had the largest decrease in serum cholesterol (1.35 mmol/L). CONCLUSIONS: The decrease in serum cholesterol is substantially larger than reported for many other high-income countries, and occurred in parallel with changes in dietary fat intakes and, for older adults, increased use of cholesterol-lowering medications. IMPLICATION: Given the demonstrated role of reduced saturated fat intake on lowering serum cholesterol, and as population average serum cholesterol levels and saturated fat intakes exceed recommended levels, initiatives to further encourage reductions in saturated fat are imperative.

Optimal serum selenium concentrations are associated with lower depressive symptoms and negative mood among young adults.

BACKGROUND: There is evidence that low, and possibly high, selenium status is associated with depressed mood. More evidence is needed to determine whether this pattern occurs in young adults with a wide range of serum concentrations of selenium. OBJECTIVE: The aim of this study was to determine if serum selenium concentration is associated with depressive symptoms and daily mood states in young adults. METHODS: A total of 978 young adults (aged 17-25 y) completed the Center for Epidemiological Studies-Depression scale and reported their negative and positive mood daily for 13 d using an Internet diary. Serum selenium concentration was determined by inductively coupled plasma mass spectrometry. ANCOVA and regression models tested the linear and curvilinear associations between decile of serum selenium concentration and mood outcomes, controlling for age, gender, ethnicity, BMI, and weekly alcohol intake. Smoking and childhood socioeconomic status were further controlled in a subset of participants. RESULTS: The mean ± SD serum selenium concentration was 82 ± 18 µg/L and ranged from 49 to 450 µg/L. Participants with the lowest serum selenium concentration (62 ± 4 µg/L; decile 1) and, to a lesser extent, those with the highest serum selenium concentration (110 ± 38 µg/L; decile 10) had significantly greater adjusted depressive symptoms than did participants with midrange serum selenium concentrations (82 ± 1 to 85 ± 1 µg/L; deciles 6 and 7). Depressive symptomatology was lowest at a selenium concentration of ∼85 µg/L. Patterns for negative mood were similar but more U-shaped. Positive mood showed an inverse U-shaped association with selenium, but this pattern was less consistent than depressive symptoms or negative mood. CONCLUSIONS: In young adults, an optimal range of serum selenium between ∼82 and 85 µg/L was associated with reduced risk of depressive symptomatology. This range approximates the values at which glutathione peroxidase is maximal, suggesting that future research should investigate antioxidant pathways linking selenium to mood. This trial was registered with the Australian New Zealand Clinical Trials Registry as ACTRN12613000773730.

Effect of increasing voluntary folic acid food fortification on dietary folate intakes and adequacy of reproductive-age women in New Zealand.

OBJECTIVE: Mandatory folic acid fortification of breads in New Zealand was put on hold in 2009. At this time, bread manufacturers were requested to adopt greater voluntary fortification and agreed to add folic acid to approximately one-third of their bread range. We sought to evaluate the impact of increased voluntary fortification of bread and the proposed mandatory fortification programme on folate intake adequacy of reproductive-age women. DESIGN: Cross-sectional study conducted in 2008. Dietary data were collected using 3 d weighed food records and usual folate intakes were generated by modifying the food composition table as follows: (i) voluntary fortification of bread as of 2008 (six breads); (ii) increased voluntary fortification of bread as of 2011 (thirty-four breads); and (iii) mandatory fortification of all breads. The prevalence of inadequate folate intake was calculated for all three scenarios using the Estimated Average Requirement (320 µg dietary folate equivalents/d) cut-point method. SETTING: New Zealand. SUBJECTS: Healthy non-pregnant women (n 125) aged 18-40 years. RESULTS: Usual folate intake in 2008 was 362 µg dietary folate equivalents/d. Increased voluntary bread fortification led to a marginal increase in folate intakes (394 µg dietary folate equivalents/d) and a decline in inadequacy from 37 % to 29 %. Mandatory fortification resulted in an increase of 89 µg folic acid/d, which substantially shifted both the proportion of women with folic acid intakes above 100 µg/d and the distribution of overall folate intakes, producing a marked reduction in inadequacy to 5 %. CONCLUSIONS: Increased voluntary bread fortification efforts are far inferior to mandatory fortification as a reliable public health intervention.

Blood pressure and hypertension in New Zealand: results from the 2008/09 Adult Nutrition Survey.

AIMS: To report the blood pressure results from the 2008/09 New Zealand Adult Nutrition Survey (2008/09NZANS). METHODS: Blood pressure measurements were available for 4,407 adults who were part of a survey involving face-to-face interviews with 4,721 New Zealanders aged 15 years and over. Three measurements were taken one minute apart, and the mean of the second and third readings has been used for this analysis. Hypertension was defined as systolic blood pressure (SBP) greater than and equal to 140 mmHg or diastolic blood pressure (DBP) greater than and equal to 90 mmHg or self reported use of antihypertensive medications. Comparisons were made with previously published New Zealand population blood pressure estimates. RESULTS: Mean SBP for the New Zealand adult population was 126 mmHg. The prevalence of hypertension was 31%, with 15% reporting taking antihypertensive medication. Mean SBP has increased since 2002/03 for New Zealand European and others (NZEO) aged 35-54 years and Maori aged 35-74 years, reversing a downward trend observed in NZEO between 1982 and 2002. CONCLUSIONS: The increasing blood pressure levels are concerning. Given the importance of elevated blood pressure as a risk factor for cardiovascular disease, intensive screening, public health measures aimed at lowering population blood pressure, and further population monitoring are warranted.

Estimation of usual intake and food sources of choline and betaine in New Zealand reproductive age women.

Recently, choline has been associated with neurodevelopment, cognitive function and neural tube defect incidence. However, data on usual intakes are limited, and estimates of dietary intakes of choline and its metabolite betaine, are not available for New Zealanders. The objective of the present study was to determine usual intake and food sources of choline and betaine in a group of New Zealand reproductive age women. Dietary intake data were collected from a sample of 125 women, aged 18-40 years, by means of a 3-day weighed food record, and usual choline and betaine intake distributions were determined. The mean (SD) daily intakes of choline and betaine were 316 (66) mg and 178 (66) mg, respectively. The total choline intake relative to energy intake and body weight was 0.18 mg/kcal and 5.1 mg/kg, respectively. Only 16% of participants met or exceeded the Adequate Intake (AI) for adult women of 425 mg of choline. The top five major food contributors of choline were eggs, red meat, milk, bread and chicken; and of betaine were bread, breakfast cereal, pasta, grains and root vegetables (carrots, parsnips, beetroot, swedes). Our findings contribute towards the recent emergence of published reports on the range of dietary choline and betaine intakes consumed by free-living populations. In our sample of New Zealand women, few participants were meeting or exceeding the AI level. Given recent epidemiological evidence suggesting health benefits of increased choline and betaine intakes, recommendations should be made to encourage the consumption of choline and betaine-rich foods.

Prevalence of diagnosed and undiagnosed diabetes and prediabetes in New Zealand: findings from the 2008/09 Adult Nutrition Survey.

AIM: To describe the prevalence of diagnosed and undiagnosed diabetes and prediabetes for New Zealand adults. METHODS: The 2008/09 New Zealand Adult Nutrition Survey was a nationally representative, cross-sectional survey of 4,721 New Zealanders aged 15 years and above. Self-reported diabetes and the 2010 American Diabetes Association cutoffs for HbA1c were used to define diagnosed diabetes, undiagnosed diabetes and prediabetes. Prevalence rates were calculated and age-specific diagnosed diabetes rates were compared with those from the Virtual Diabetes Register. RESULTS: Overall, prevalence of diabetes was 7.0%, and prevalence of prediabetes 18.6%. Prevalence of diabetes was higher in men (8.3%, 95% CI: 6.4, 10.1) than in women (5.8%, 95% CI: 4.7, 7.0), and was higher among the obese (14.2%, 95% CI: 11.6, 16.9) compared with the normal weight group (2.4%, 95% CI: 1.4, 3.6). Prevalence of undiagnosed diabetes was highest among Pacific people (6.4%, 95% CI: 3.8, 9.1) compared with Maori (2.2%, 95% CI: 1.2, 3.1) and New Zealand European and Others (1.5%, 95% CI: 0.9, 2.1). CONCLUSION: The high prevalence of prediabetes indicates the prevalence of diabetes will continue to increase in New Zealand. Implementation of effective evidence-based prevention strategies is required to reduce the increasing costs of the diabetes epidemic.

Influence of the glutathione peroxidase 1 Pro200Leu polymorphism on the response of glutathione peroxidase activity to selenium supplementation: a randomized controlled trial.

BACKGROUND: A genetic variant at codon 200 (Pro200Leu) of the gene encoding for glutathione peroxidase 1 (GPx1), a selenium-dependent enzyme, is associated with lower enzyme activity; however, the evidence is limited to in vitro and observational studies. OBJECTIVE: The objective was to determine whether the GPx1 Pro200Leu genetic variants modify the response of whole-blood glutathione peroxidase (GPx) activity to selenium supplementation in patients with coronary artery disease in New Zealand. DESIGN: The results from 2 parallel-design, double-blind trials were combined. Participants were randomly assigned to receive a daily supplement of 100 µg Se as l-selenomethionine (n = 129) or placebo (n = 126) for 12 wk. Plasma selenium and whole-blood GPx activity were measured at baseline and at week 12. Participants were genotyped for the GPx1 Pro200Leu polymorphism. RESULTS: Selenium supplementation increased whole-blood GPx activity by 5 (95% CI: 4, 7) U/g hemoglobin (P < 0.001); however, the magnitude of the increase did not differ by genotype (P = 0.165 for treatment-by-genotype interaction). In an exploratory analysis, a significant nutrient-gene interaction was apparent when baseline plasma selenium concentrations were included in the regression model (P = 0.006 for treatment-by-genotype × baseline selenium concentration interaction). Increases in GPx activity were 2-fold higher in Pro homozygotes than in participants carrying a Leu allele when baseline selenium concentrations were ≤1.15 µmol/L (P < 0.05). CONCLUSIONS: These results indicate that GPx1 Pro200Leu variants do not substantially modify the response of whole-blood GPx to selenium supplementation in individuals with relatively high plasma selenium concentrations. A nutrient-gene interaction was observed when the baseline selenium concentration was low, but this requires independent confirmation. This trial was registered at www.actr.org.au as ACTRN12605000412639 and ACTRN12606000197538.

Long-term effect of low-dose folic acid intake: potential effect of mandatory fortification on the prevention of neural tube defects.

BACKGROUND: Understanding the full effect of chronic low-dose folic acid is important in interpreting the effect of the mandatory folic acid fortification program in North America. OBJECTIVE: We aimed to describe the rate of attainment and steady state (plateau) of red blood cell (RBC) folate in response to long-term intake of 140 µg (designed to mimic fortification) and 400 µg (recommended dose for the primary prevention of neural tube defects) folic acid/d in reproductive-aged women living in a country with minimal fortification. DESIGN: On the basis of pharmacokinetics principles, it was recently proposed that a steady state should be reached after 40 wk. Thus, 144 women aged 18-40 y were randomly assigned to receive a daily folic acid supplement of 140 (n = 49) or 400 (n = 48) µg or placebo (n = 47) for 40 wk. RBC folate was measured at baseline and at 6, 12, 29, and 40 wk. RESULTS: After 40 wk, RBC folate did not reach a plateau in either treatment group. Kinetic modeling of the data indicated that RBC folate would approximately double from 779 to 1356 nmol/L in response to 140 µg folic acid/d with only ≈50% of model-estimated steady state conditions achieved at 40 wk. An average RBC folate concentration of 1068 nmol/L after 12 wk of supplementation with 400 µg folic acid/d was readily achieved at 36 wk after continuous intake of 140 µg/d. CONCLUSION: Our model shows the considerable length of time required to attain the full effect of low-dose folic acid, which suggests that 140 µg folic acid/d could be as effective as 400 µg folic acid/d taken during the periconceptional period if given sufficient time. This trial is registered at www.anzctr.org.au as ACTRN12609000215224.

Folate status of reproductive age women and neural tube defect risk: the effect of long-term folic acid supplementation at doses of 140 µg and 400 µg per day.

Primary prevention of most folate-responsive neural tube defects (NTDs) may not require 400 µg folic acid/day but may be achieved by attaining a high maternal folate status. Using RBC folate ≥906 nmol/L as a marker for NTD risk reduction, the study aimed to determine the change in blood folate concentrations in reproductive age women in response to long-term folic acid supplementation at 400 µg/day and 140 µg/day (dose designed to mimic the average daily folic acid intake received from New Zealand's proposed mandatory bread fortification program). Participants were randomly assigned to a daily folic acid supplement of 140 µg (n = 49), 400 µg (n = 48) or placebo (n = 47) for 40 weeks. RBC folate concentrations were measured at baseline, and after 6, 12, 29 and 40 weeks. At 40 weeks, the overall prevalence of having a RBC folate <906 nmol/L decreased to 18% and 35% in the 400 µg and 140 µg groups, respectively, while remaining relatively unchanged at 58% in the placebo group. After 40 weeks, there was no evidence of a difference in RBC folate between the two treatment groups (P = 0.340), nor was there evidence of a difference in the odds of a RBC folate <906 nmol/L (P = 0.078). In conclusion, the average daily intake of folic acid received from the proposed fortification program would increase RBC folate concentrations in reproductive age women to levels associated with a low risk of NTDs.

DXA measurements confirm that parental perceptions of elevated adiposity in young children are poor.

OBJECTIVE: To compare parental assessments of child body weight status with BMI measurements and determine whether children who are incorrectly classified differ in body composition from those whose parents correctly rate child weight. Also to ascertain whether children of obese parents differ from those of non-obese parents in actual or perceived body weight. RESEARCH METHODS AND PROCEDURES: Weights, heights, BMI, and waist girths of New Zealand children ages 3 to 8 years were determined. Fat mass, fat percentage, and lean mass were measured by DXA (n = 96). Parents classified child weight status as underweight, normal-weight, slightly overweight, or overweight. Centers for Disease Control and Prevention 2000 percentiles of BMI were used. RESULTS: Parents underestimated child weight status. Despite having 83% more fat mass than children with BMI values below the 85th percentile, only 7 of 31 children with BMI values at or above the 85th percentile were rated as slightly overweight or overweight. In the whole sample, participants whose weight status was underestimated by parents (40 of the 96 children) had l9% less fat mass but similar lean mass as children whose weight status was correctly classified. However, children of obese and non-obese parents did not differ in body composition or anthropometry, and obese parents did not underestimate child weight more than non-obese parents. DISCUSSION: Because parents underestimate child weight, but BMI values at or above the 85th percentile identify high body fat well, advising parents of the BMI status of their children should improve strategies to prevent excessive fat gain in young children.