Pregnancy-induced alterations of 1-carbon metabolism and significance for maternal nutrition requirements.

OBJECTIVES: The pregnancy-induced alterations in 1-carbon (1C) metabolism, effects of advancing gestation on maternal plasma concentrations of methyl nutrients, and potential implications for maternal dietary intake and infant clinical outcomes are summarized in this narrative review. BACKGROUND: 1C metabolism encompasses a series of pathways where 1C units are transferred among nutrients such as B vitamins, choline, and amino acids (the methyl nutrients). Use of isotopic tracers and measuring methyl nutrients in maternal plasma and infant cord blood has advanced the understanding of 1C flux in pregnancy and kinetics of maternal-placental-fetal transfer. Methyl nutrients are supplied from maternal plasma to the placenta and fetus to support growth and 1C metabolism in these compartments. METHODS: A literature review was completed in MEDLINE and Google Scholar using search terms related to 1C metabolism, methyl nutrients, and nutrition requirements in pregnancy. English-language articles were reviewed in which 1C metabolism in pregnancy, maternal-placental-fetal transfer of methyl nutrients, and determinants of maternal plasma concentrations of methyl nutrients among healthy pregnant women were assessed. DISCUSSION: Adaptations in 1C metabolism occur throughout a healthy pregnancy to support this unique period of accelerated growth. Studies report similar temporal changes in plasma concentrations of many methyl nutrients, including B vitamins, choline, betaine, methionine, and cysteine, among healthy pregnant women from diverse geographic regions. Other key findings discussed in this review include an apparent high degree of B vitamin transfer to the placenta and fetus, influence of choline supplementation on 1C flux and possible benefit of supplementation for infant cognitive development, and that glycine may be conditionally essential in pregnancy. CONCLUSION: Understanding the flux of 1C metabolism in pregnancy and methyl nutrient transfer from maternal plasma is needed to establish appropriate plasma references ranges and, ultimately, dietary recommendations that aim to prevent deficiency and associated adverse health outcomes for mother and baby.

Daily Oral Supplementation with 60 mg of Elemental Iron for 12 Weeks Alters Blood Mitochondrial DNA Content, but Not Leukocyte Telomere Length in Cambodian Women.

There is limited evidence regarding the potential risk of untargeted iron supplementation, especially among individuals who are iron-replete or have genetic hemoglobinopathies. Excess iron exposure can increase the production of reactive oxygen species, which can lead to cellular damage. We evaluated the effect of daily oral supplementation on relative leukocyte telomere length (rLTL) and blood mitochondrial DNA (mtDNA) content in non-pregnant Cambodian women (18-45 years) who received 60 mg of elemental iron as ferrous sulfate (n = 190) or a placebo (n = 186) for 12 weeks. Buffy coat rLTL and mtDNA content were quantified by monochrome multiplex quantitative polymerase chain reaction. Generalized linear mixed-effects models were used to predict the absolute and percent change in rLTL and mtDNA content after 12 weeks. Iron supplementation was not associated with an absolute or percent change in rLTL after 12 weeks compared with placebo (ß-coefficient: -0.04 [95% CI: -0.16, 0.08]; p = 0.50 and ß-coefficient: -0.96 [95% CI: -2.69, 0.77]; p = 0.28, respectively). However, iron supplementation was associated with a smaller absolute and percent increase in mtDNA content after 12 weeks compared with placebo (ß-coefficient: -11 [95% CI: -20, -2]; p = 0.02 and ß-coefficient: -11 [95% CI: -20, -1]; p= 0.02, respectively). Thus, daily oral iron supplementation for 12 weeks was associated with altered mitochondrial homeostasis in our study sample. More research is needed to understand the risk of iron exposure and the biological consequences of altered mitochondrial homeostasis in order to inform the safety of the current global supplementation policy.

Baseline Hemoglobin, Hepcidin, Ferritin, and Total Body Iron Stores are Equally Strong Diagnostic Predictors of a Hemoglobin Response to 12 Weeks of Daily Iron Supplementation in Cambodian Women.

BACKGROUND: The WHO recommends daily iron supplementation for all women in areas where the population-level anemia prevalence is ≥40%, despite the fact that hemoglobin (Hb) concentration is generally considered to be a poor prognostic indicator of iron status. OBJECTIVES: In this secondary analysis, we investigated the predictive power of ten baseline hematological biomarkers towards a 12-week Hb response to iron supplementation. METHODS: Data were obtained from a randomized controlled trial of daily iron supplementation in 407 nonpregnant Cambodian women (18-45 years) who received 60 mg elemental iron as ferrous sulfate for 12 weeks. Ten baseline biomarkers were included: Hb, measured with both a hematology analyzer and a HemoCue; inflammation-adjusted ferritin; soluble transferrin receptor; reticulocyte Hb; hepcidin; mean corpuscular volume; inflammation-adjusted total body iron stores (TBIS); total iron binding capacity; and transferrin saturation. Receiver operating characteristic (ROC) curves from fitted logistic regression models were used to make discrimination comparisons and variable selection methods were used to construct a multibiomarker prognostic model. RESULTS: Only 25% (n = 95/383) of women who completed the trial experienced a 12-week Hb response ≥10 g/L. The strongest univariate predictors of a Hb response were Hb as measured with a hematology analyzer, inflammation-adjusted ferritin, hepcidin, and inflammation-adjusted TBIS (AUCROC = 0.81, 0.83, 0.82, and 0.82, respectively), and the optimal cutoffs to identify women who were likely to experience a Hb response were 117 g/L, 17.3 µg/L, 1.98 nmol/L, and 1.95 mg/kg, respectively. Hb as measured with a hematology analyzer, inflammation-adjusted ferritin, and hepcidin had the best combined predictive ability (AUCROC=0.86). Hb measured with the HemoCue had poor discrimination ability (AUCROC = 0.65). CONCLUSIONS: Baseline Hb as measured with a hematology analyzer was as strong a predictor of Hb response to iron supplementation as inflammation-adjusted ferritin, hepcidin, and inflammation-adjusted TBIS. This is positive given that the WHO currently uses the population-level anemia prevalence to guide recommendations for untargeted iron supplementation.

Dietary Riboflavin Intake and Riboflavin Status in Young Adult Women Living in Metro Vancouver, Canada.

BACKGROUND: Nutrition surveys suggest that <10% of Canadian adults have inadequate riboflavin intakes. However, biochemical riboflavin deficiency [erythrocyte glutathione reductase activity coefficient (EGRac) ≥1.40] has been reported in 41% of young adult women living in Metro Vancouver. Canadian Chinese ethnicity comprise >25% of Vancouver's population and are postulated to have poorer riboflavin status than those of European ethnicity because they could be less likely to consume dairy products and fortified wheat. OBJECTIVES: The objectives of this study were to determine dietary riboflavin intake and food sources, and to assess the association between riboflavin intake and status in young women of European (n = 107) and Chinese (n = 91) ethnicities living in Metro Vancouver, Canada. METHODS: This was a cross-sectional study conducted in women (aged 19-45 y). Women were healthy, not pregnant or breastfeeding, of European or Chinese ethnicities, and not taking riboflavin-containing supplements for the past 4 mo. Dietary riboflavin intake was assessed using the past-year Diet History Questionnaire II, and riboflavin status (EGRac) was measured in fasting venous blood samples. RESULTS: Only 7% of participants had dietary riboflavin intakes below the Estimated Average Requirement (0.9 mg/d), but 40% of women had biochemical riboflavin deficiency (EGRac ≥1.40). Although more Canadian women of European ethnicity than Chinese ethnicity had biochemical riboflavin deficiency (46% and 34%; P < 0.001), median dietary riboflavin intake did not differ (1.73 and 1.82 mg/d; P = 0.587). Dairy products and vegetables contributed the most to riboflavin intake. Energy-adjusted dietary riboflavin intake was inversely associated with EGRac (B = -0.04, 95% CI: -0.07, -0.01). However, after further adjustment the relation was not significant. CONCLUSIONS: Overall, women of reproductive age living in Metro Vancouver, Canada, had a low prevalence of inadequate dietary riboflavin intake despite the high prevalence of apparent biochemical riboflavin deficiency.

Including 60 mg Elemental Iron in a Multiple Micronutrient Supplement Blunts the Increase in Serum Zinc after 12 Weeks of Daily Supplementation in Predominantly Anemic, Nonpregnant Cambodian Women of Reproductive Age.

BACKGROUND: Multiple micronutrient (MMN) supplementation may result in interaction effects due to competing absorptive pathways of trace elements. OBJECTIVES: The aim of this study was to investigate the effect of MMN supplementation with or without iron on serum zinc, selenium, and copper concentrations in Cambodian women. METHODS: In a 2 × 2 factorial double-blind randomized 12-wk trial, predominantly anemic, nonpregnant women (aged 18-45 y) received daily 60 mg of iron (Fe; n = 201); 14 other micronutrients including zinc (15 mg), selenium (65 µg), and copper (2 mg), but no iron (MMN; n = 202); 60 mg iron plus MMN (Fe + MMN; n = 206); or a placebo (n = 200). Fasting morning blood was collected at baseline and 12 wk from women in 26 villages in Kampong Chhnang province. Serum zinc, selenium, and copper concentrations (secondary outcomes of the randomized controlled trial) were measured using inductively coupled plasma mass spectrometry. Generalized linear regression was used to estimate intervention effects [ß coefficient (95% CI)] for Fe (with or without MMN) and MMN (with or without Fe) after testing for the presence of an Fe × MMN interaction. RESULTS: A total of 760 women completed the trial. Zinc deficiency prevalence at baseline was 45% (inflammation-adjusted serum zinc <10.7 µmol/L). A significant Fe × MMN interaction (P = 0.02) was detected in the 2 × 2 analysis with serum zinc concentration as the outcome: the MMN group had a higher mean serum zinc concentration at 12 wk (12.3 µmol/L; 95% CI: 12.2, 12.4 µmol/L) compared with all other groups, and the Fe + MMN group had a higher mean serum zinc concentration (11.6 µmol/L; 95% CI: 11.5, 11.7 µmol/L) compared with the Fe group (11.0 µmol/L; 95% CI: 10.9, 11.0 µmol/L) and the placebo group (11.2 µmol/L; 95% CI: 11.1, 11.4 µmol/L). CONCLUSIONS: The inclusion of 60 mg iron in the daily MMN formulation may be interfering with the absorption and/or metabolism of supplemental zinc in Cambodian women. This is of particular concern when MMN supplementation is implemented in populations with risk of zinc deficiency. This trial was registered at clinicaltrials.gov as NCT-02481375.

Concentrations of Water-Soluble Forms of Choline in Human Milk from Lactating Women in Canada and Cambodia.

Choline has critical roles during periods of rapid growth and development, such as infancy. In human milk, choline is mostly present in water-soluble forms (free choline, phosphocholine, and glycerophosphocholine). It is thought that milk choline concentration is influenced by maternal choline intake, and the richest food sources for choline are of animal origin. Scarce information exists on milk choline from countries differing in animal-source food availability. In this secondary analysis of samples from previous trials, the concentrations of the water-soluble forms of choline were quantified by liquid chromatography-tandem mass spectrometry in mature milk samples collected from lactating women in Canada (n = 301) and in Cambodia (n = 67). None of the water-soluble forms of choline concentrations in milk differed between Canada and Cambodia. For all milk samples (n = 368), free choline, phosphocholine, glycerophosphocholine, and the sum of water-soluble forms of choline concentrations in milk were (mean (95%CI)) 151 (141, 160, 540 (519, 562), 411 (396, 427), and 1102 (1072, 1133) µmol/L, respectively. Theoretically, only 19% of infants would meet the current Adequate Intake (AI) for choline. Our findings suggest that the concentrations in milk of water-soluble forms of choline are similar in Canada and Cambodia, and that the concentration used to set the infant AI might be inaccurate.

The Use of Multivitamin/Multimineral Supplements: A Modified Delphi Consensus Panel Report.

PURPOSE: Evidence supporting the use of dietary supplements, in particular, multivitamin/multimineral supplements (MVMS), has been mixed, complicating the ability of health care professionals to recommend their use. To clarify the role that MVMS can play in supporting human health, a series of consensus statements was developed based on expert opinion. METHODS: A panel of 14 international experts in nutritional science and health care was convened to develop consensus statements related to using MVMS in supporting optimal human health. The modified Delphi process included 2 rounds of remote voting and a final round of voting at a roundtable meeting where evidence summaries were presented and discussed. The level of agreement with each of 9 statements was rated on a 5-point Likert scale: agree strongly; agree with reservation; undecided; disagree; or disagree strongly. Consensus was predefined as ≥80% of the panel agreeing strongly or agreeing with reservation to a given statement. FINDINGS: Consensus was reached for all statements. The panel determined that MVMS can broadly improve micronutrient intakes when they contain at least the micronutrients that are consumed insufficiently or have limited bioavailability within a specified population. MVMS formulations may also be individualized according to age, sex, life cycle, and/or other selected characteristics. There are specific biological processes and health outcomes associated with deficient, inadequate, and adequate micronutrient levels. Adequate intake is necessary for normal biological functioning required for good health; in some instances, higher than recommended micronutrient intakes have the potential to provide additional health benefits. Meeting daily intakes established by dietary reference values should be an explicit public health goal for individuals and populations. Use of MVMS is one approach to ensure that adequate micronutrient needs are met in support of biological functions necessary to maintain health. Long-term use of MVMS not exceeding the upper limit of recommended intakes has been determined to be safe in healthy adults. There is insufficient evidence to indicate that MVMS are effective for the primary prevention of chronic medical conditions, including cardiovascular disease and cancer. However, for certain otherwise healthy subpopulations (eg, pregnant women, older adults) and some individuals with existing medical conditions who experience inadequacies in micronutrient intake, addressing inadequacies by using MVMS can provide health benefits. IMPLICATIONS: This consensus panel has described key issues related to the use of MVMS among individuals at risk of or presenting with inadequacies in micronutrient intake or biomarker status.

The effect of oral iron with or without multiple micronutrients on hemoglobin concentration and hemoglobin response among nonpregnant Cambodian women of reproductive age: a 2 x 2 factorial, double-blind, randomized controlled supplementation trial.

Background: Despite a high prevalence of anemia among nonpregnant Cambodian women, current reports suggest that iron deficiency (ID) prevalence is low. If true, iron supplementation will not be an effective anemia reduction strategy.Objective: We measured the effect of daily oral iron with or without multiple micronutrients (MMNs) on hemoglobin concentration in nonpregnant Cambodian women screened as anemic.Design: In this 2 × 2 factorial, double-blind, randomized trial, nonpregnant women (aged 18-45 y) with hemoglobin concentrations ≤117 g/L (capillary blood) were recruited from 26 villages in Kampong Chhnang province and randomly assigned to receive 12 wk of iron (60 mg; Fe group), MMNs (14 other micronutrients; MMN group), iron plus MMNs (Fe+MMN group), or placebo capsules. A 2 × 2 factorial intention-to-treat analysis with the use of a generalized mixed-effects model was used to assess the effects of iron and MMNs and the interaction between these factors. Results: In July 2015, 809 women were recruited and 760 (94%) completed the trial. Baseline anemia prevalence was 58% (venous blood). Mean (95% CI) hemoglobin concentrations at 12 wk in the Fe, MMN, Fe+MMN, and placebo groups were 121 (120, 121), 116 (116, 117), 123 (122, 123), and 116 (116, 117) g/L, with no iron × MMN interaction (P = 0.66). Mean (95% CI) increases in hemoglobin were 5.6 g/L (3.8, 7.4 g/L) (P < 0.001) among women who received iron (n = 407) and 1.2 g/L (-0.6, 3.0 g/L) (P = 0.18) among women who received MMNs (n = 407). The predicted proportions (95% CIs) of women with a hemoglobin response (≥10 g/L at 12 wk) were 19% (14%, 24%), 9% (5%, 12%), 30% (24%, 35%), and 5% (2%, 9%) in the Fe, MMN, Fe+MMN, and placebo groups, respectively.Conclusions: Daily iron supplementation for 12 wk increased hemoglobin in nonpregnant Cambodian women; however, MMNs did not confer additional significant benefit. Overall, ∼24% of women who received iron responded after 12 wk; even fewer would be likely to respond in the wider population. This trial was registered at clinicaltrials.gov as NCT02481375.

Correlations between Maternal, Breast Milk, and Infant Vitamin B12 Concentrations among Mother-Infant Dyads in Vancouver, Canada and Prey Veng, Cambodia: An Exploratory Analysis.

Vitamin B12 plays an essential role in fetal and infant development. In regions where animal source food consumption is low and perinatal supplementation is uncommon, infants are at risk of vitamin B12 deficiency. In this secondary analysis, we measured total vitamin B12 concentrations in maternal and infant serum/plasma and breast milk among two samples of mother-infant dyads in Canada (assessed at 8 weeks post-partum) and in Cambodia (assessed between 3-27 weeks post-partum). Canadian mothers (n = 124) consumed a daily vitamin B12-containing multiple micronutrient supplement throughout pregnancy and lactation; Cambodian mothers (n = 69) were unsupplemented. The maternal, milk, and infant total vitamin B12 concentrations (as geometric means (95% CI) in pmol/L) were as follows: in Canada, 698 (648,747), 452 (400, 504), and 506 (459, 552); in Cambodia, 620 (552, 687), 317 (256, 378), and 357 (312, 402). The majority of participants were vitamin B12 sufficient (serum/plasma total B12 > 221 pmol/L): 99% and 97% of mothers and 94% and 84% of infants in Canada and Cambodia, respectively. Among the Canadians, maternal, milk, and infant vitamin B12 were all correlated (p < 0.05); only maternal and infant vitamin B12 were correlated among the Cambodians (p < 0.001).

High prevalence of suboptimal vitamin B12 status in young adult women of South Asian and European ethnicity.

Suboptimal vitamin B12 (B12) status has been associated with an increased risk of congenital anomalies, preterm birth, and childhood insulin resistance. South Asians - Canada's largest minority group - and women of reproductive age are vulnerable to B12 deficiency. This study aimed to assess the prevalence of and factors associated with B12 deficiency and suboptimal B12 status in a convenience sample of young adult women of South Asian and European descent in Metro Vancouver. We measured serum B12, holotranscobalamin, plasma methylmalonic acid, red blood cell and plasma folate, and hematologic parameters in 206 nonpregnant, healthy women aged 19-35 years. Categorization for B12 status adhered to serum B12 cutoffs for deficiency (<148 pmol/L) and suboptimal B12 status (148-220 pmol/L). We collected demographic, lifestyle, and dietary intake data and conducted genotyping for common genetic variants linked to B-vitamin metabolism. The prevalence of deficiency and suboptimal B12 status were 14% and 20%, respectively. Serum vitamin B12 concentrations were negatively associated with oral contraceptive use and first-generation immigrant status, and positively with dietary B12 intake and B12 supplement use. The prevalence of B12 inadequacy in this sample of highly educated women is higher than in the general Canadian population. In light of maternal and fetal health risks associated with B12 inadequacy in early-pregnancy, practitioners should consider monitoring B12 status before and during early pregnancy, especially in immigrants and women with low dietary B12 intakes including non-users of vitamin supplements.

Maternal vitamin D3 supplementation at 50 µg/d protects against low serum 25-hydroxyvitamin D in infants at 8 wk of age: a randomized controlled trial of 3 doses of vitamin D beginning in gestation and continued in lactation.

BACKGROUND: Vitamin D supplementation is recommended for breastfed infants. Maternal supplementation beginning in gestation is a potential alternative, but its efficacy in maintaining infant 25-hydroxyvitamin D [25(OH)D] concentration after birth is unknown. OBJECTIVES: We determined the effect of 3 doses of maternal vitamin D supplementation beginning in gestation and continued in lactation on infant serum 25(OH)D and compared the prevalence of infant serum 25(OH)D cutoffs (>30, >40, >50, and >75 nmol/L) by dose at 8 wk of age. DESIGN: Pregnant women (n = 226) were randomly allocated to receive 10, 25, or 50 µg vitamin D3/d from 13 to 24 wk of gestation until 8 wk postpartum, with no infant supplementation. Mother and infant blood was collected at 8 wk postpartum. RESULTS: At 8 wk postpartum, mean [nmol/L (95% CI)] infant 25(OH)D at 8 wk was higher in the 50-µg/d [75 (67, 83)] than in the 25-µg/d [52 (45, 58)] or 10-µg/d [45 (38, 52)] vitamin D groups (P < 0.05). Fewer infants born to mothers in the 50-µg/d group had a 25(OH)D concentration <30 nmol/L (indicative of deficiency) than infants in the 25- and 10-µg/d groups, respectively (2% compared with 16% and 43%; P < 0.05). Fewer than 15% of infants in the 10- or 25-µg/d groups achieved a 25(OH)D concentration >75 nmol/L compared with 44% in the 50-µg/d group (P < 0.05). Almost all infants (∼98%, n = 44) born to mothers in the 50-µg/d group achieved a 25(OH)D concentration >30 nmol/L. At 8 wk postpartum, mean maternal 25(OH)D concentration was higher in the 50-µg/d [88 (84, 91)] than in the 25-µg/d [78 (74, 81)] or 10-µg/d [69 (66, 73)] groups (P < 0.05). CONCLUSIONS: Maternal supplementation beginning in gestation with 50 µg vitamin D3/d protects 98% of unsupplemented breastfed infants against 25(OH)D deficiency (<30 nmol/L) to at least 8 wk, whereas 10 or 25 µg vitamin D/d protects only 57% and 84% of infants, respectively.

Acute Beetroot Juice Supplementation Does Not Improve Cycling Performance in Normoxia or Moderate Hypoxia.

Beetroot juice (BR) has been shown to lower the oxygen cost of exercise in normoxia and may have similar effects in hypoxia. We investigated the effect of BR on steady-state exercise economy and 10-km time trial (TT) performance in normoxia and moderate hypoxia (simulated altitude: ~2500 m). Eleven trained male cyclists (VO 2peak ≥ 60 ml · kg(-1) · min(-1)) completed four exercise trials. Two hours before exercise, subjects consumed 70 mL BR (~6 mmol nitrate) or placebo (nitrate-depleted BR) in a randomized, double-blind manner. Subjects then completed a 15-min self-selected cycling warm-up, a 15-min steady-state exercise bout at 50% maximum power output, and a 10-km time trial (TT) in either normoxia or hypoxia. Environmental conditions were randomized and single-blind. BR supplementation increased plasma nitrate concentration and fraction of exhaled nitric oxide relative to PL (p < .05 for both comparisons). Economy at 50% power output was similar in hypoxic and normoxic conditions (p > .05), but mean power output was greater in the normoxic TT relative to the hypoxic TT (p < .05). BR did not affect economy, steady-state SpO2, mean power output, or 10-km TT completion time relative to placebo in either normoxia or hypoxia (p > .05 in all comparisons). In conclusion, BR did not lower the oxygen cost of steady-state exercise or improve exercise performance in normoxia or hypoxia in a small sample of well-trained male cyclists.

Vitamin D supplementation is associated with higher serum 25OHD in Asian and White infants living in Vancouver, Canada.

To prevent rickets, the Health Canada and the American Academy of Pediatrics recommend that breastfed infants receive a daily vitamin D supplement of 10 µg d(-1) . Compliance with this recommendation is variable and its effect on infant vitamin D status is unclear. We measured serum 25-hydroxyvitamin D (25OHD) in Asian immigrant (n=28) and White (n=37) mothers and their infants aged 2-4 months living in Vancouver (49°N). Mothers completed health and demographic questionnaires. All subjects were term infants who were primarily breastfed. Analysis of variance, χ(2) , multiple regression and logistic regression analysis were performed as appropriate. Mean 25OHD of the infants was 31 (95% confidence interval 28-34) ng mL(-1) . Only two infants had a 25OHD concentration indicative of deficiency, <10 ng mL(-1) . Of the infants, 14% (n=9) and 49% (n=32) were vitamin D insufficient based on two commonly used cut-offs of 20 and 30 ng mL(-1) , respectively. Fifty-eight (89%) infants had been given a vitamin D supplement. Mean 25OHD was 9.4 ng mL(-1) higher in infants consuming ≥10 µg d(-1) of vitamin D from supplements vs. those consuming less (P=0.003). Mother's 25OHD, season, skin colour or ethnicity (Asian vs. White) did not influence infant 25OHD. The infants in our study, most of whom received vitamin D supplements, were generally protected against low 25OHD. The study was limited by sample size and the nature of the cross-sectional study design.

Breakfast consumption is positively associated with nutrient adequacy in Canadian children and adolescents.

Although breakfast is associated with more favourable nutrient intake profiles in children, limited data exist on the impact of breakfast on nutrient adequacy and the potential risk of excessive intakes. Accordingly, we assessed differences in nutrient intake and adequacy among breakfast non-consumers, consumers of breakfasts with ready-to-eat cereal (RTEC) and consumers of other types of breakfasts. We used cross-sectional data from 12,281 children and adolescents aged 4-18 years who took part in the nationally representative Canadian Community Health Survey, 2004. Mean nutrient intakes (obtained using a multiple-pass 24 h recall method) were compared among the breakfast groups using covariate-adjusted regression analysis. Usual nutrient intake distributions, generated using the National Cancer Institute method, were used to determine the prevalence of nutrient inadequacy or the potential risk of excessive intakes from food sources alone and from the combination of food plus supplements. Of these Canadian children, 10% were breakfast non-consumers, 33% were consumers of RTEC breakfasts and 57% were consumers of other types of breakfasts. Non-consumption of breakfast increased with age (4-8 years: 2%; 9-13 years: 9%; 14-18 years: 18%). Breakfast consumers had higher covariate-adjusted intakes of energy, many nutrients and fibre, and lower fat intakes. The prevalence of nutrient inadequacy for vitamin D, Ca, Fe and Mg (from food alone or from the combination of food plus supplements) was highest in breakfast non-consumers, intermediate in consumers of other types of breakfasts and lowest in consumers of RTEC breakfast. For vitamin A, P and Zn, breakfast non-consumers had a higher prevalence of nutrient inadequacy than both breakfast groups. The potential risk of excessive nutrient intakes was low in all groups. Efforts to encourage and maintain breakfast consumption in children and adolescents are warranted.

Effectiveness and safety of a high-dose weekly vitamin D (20,000 IU) protocol in older adults living in residential care.

OBJECTIVES: To report 25 hydroxyvitamin D (25OHD) concentrations, an indicator of vitamin D status, in older adults living in residential care 1 year after a protocol of weekly 20,000 IU of vitamin D was started. DESIGN: Cross-sectional. SETTING: Five residential care facilities in British Columbia, Canada. PARTICIPANTS: Residents aged 65 and older from five facilities (N=236). MEASUREMENTS: Participants provided a blood sample. Demographic and health information was obtained from the medical record. RESULTS: Mean 25OHD was 102 nmol/L (95% confidence interval (CI)=98-106 nmol/L). Three percent of residents had a 25OHD concentration of less than 40 nmol/L, 6% <50 nmol/L, and 19% <75 nmol/L. In those who received 20,000 IU/wk or more for 6 months or longer (n=147), mean 25OHD was 112 nmol/L (95% CI=108-117 nmol/L), and none had a 25OHD level of less than 50 nmol/L. Hypercalcemia (>2.6 mmol/L), a potential consequence of too much vitamin D, was present in 14%, although 25OHD levels did not differ in those with and without hypercalcemia (108 vs 101 nmol/L; P=.17). CONCLUSION: Twelve months after implementation of a 20,000-IU/wk vitamin D protocol for older adults in residential care, mean 25OHD concentrations were high, and there was no evidence of poor vitamin D status. Given the absence of demonstrated benefit of high 25OHD concentrations to the residential care population, dosages less than 20,000 IU/wk of vitamin D are recommended.

25-Hydroxyvitamin D concentrations in children with Crohn's disease supplemented with either 2000 or 400 IU daily for 6 months: a randomized controlled study.

OBJECTIVES: To assess vitamin D status of pediatric patients with Crohn's disease (CD) and to compare their serum 25-hydroxyvitamin D (s-25OHD) with established cutoffs and assess whether 6 months of supplementation with 2000 IU/d, vs 400 IU/d, would reduce the group prevalence of vitamin D below these cutoffs. STUDY DESIGN: Subjects 8-18 years (n = 83) with quiescent CD were randomized to either 400 or 2000 IU vitamin D3/d for 6 months. RESULTS: Baseline mean ± SD s-25OHD was 24 ± 8 ng/mL; 13 subjects (16%) had an s-25OHD <16 ng/mL, 27 (33%) < 20 ng/mL, and 65 (79%) < 30 ng/mL. There was no significant difference between groups in achieving the cutoffs of 16 ng/mL or 20 ng/mL at 6 months; however, only 35% of the 400 IU group achieved the greater cutoff of 30 ng/mL compared with 74% in the 2000 IU group (P < .001). Baseline adjusted mean s-25OHD concentrations at 6 months were 9.6 ng/mL (95% CI 6.0-13.2, P < .001) greater in the 2000 IU than the 400 IU group. Disease activity was not affected by supplement dose. Few subjects exceeded safety marker cutoffs, and this did not differ by dose. CONCLUSIONS: At baseline, a high proportion of patients had a mean s-25OHD >20 ng/mL. 2000 IU vitamin D3/d is more effective in raising s-25OHD concentrations to > 30 ng/mL in children with CD than 400 IU/d, but both treatments were equally effective at achieving 16 or 20 ng/mL.

Perceived lactose intolerance in adult Canadians: a national survey.

Although double-blind studies show that lactose-intolerant individuals can consume moderate quantities of milk products without perceptible symptoms, many who perceive that they are lactose intolerant limit or avoid milk products, potentially compromising calcium and vitamin D intakes. Adult Canadians are at risk of inadequate intakes of these nutrients, but no data exist on the prevalence, correlates, and potential impact of perceived lactose intolerance among Canadians. To address this, a Web-based survey of a population-representative sample of 2251 Canadians aged ≥19 years was conducted. Overall, 16% self-reported lactose intolerance. This was more common in women (odds ratio (OR), 1.84; 95% CI, 1.46-2.33) and in nonwhites (OR, 1.79; 95% CI, 1.24-2.58) and less common in those >50 years of age (OR, 0.71; 95% CI, 0.56-0.90) and in those completing the survey in French (OR, 0.74; 95% CI, 0.56-0.99). Those with self-reported lactose intolerance had lower covariate-adjusted milk product and alternative intakes (mean ± SE; 1.40 ± 0.08 servings·day(-1) vs. 2.33 ± 0.03 servings·day(-1), p < 0.001). A greater proportion used supplements containing calcium (52% vs. 37%, p < 0.001) and vitamin D (58% vs. 46%, p < 0.001), but calcium intakes from the combination of milk products, alternatives, and supplements were lower (739 ± 30 mg·day(-1) vs. 893 ± 13 mg·day(-1), p < 0.0001). Variation in self-reported lactose intolerance by sex, age, and language preference was unexpected and suggests that some groups may be more vulnerable to the perception that they are lactose intolerant. Regardless of whether lactose intolerance is physiologically based or perceptual, education is required to ensure that calcium intakes are not compromised.