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Background: Delayed onset of lactogenesis (OL) is most common in primiparas and increases the risk of excess neonatal weight loss, formula supplementation, and early weaning., Objective: We examined variables associated with delayed OL among first-time mothers who delivered at term and initiated breastfeeding (n = 431)., Design: We conducted in-person interviews during pregnancy and at days 0, 3, and 7 postpartum and extracted obstetric and newborn information from medical records. We defined OL as delayed if it occurred after 72 h and used chi-square analysis to examine its association with potential risk factors across 6 dimensions: 1) prenatal characteristics, 2) maternal anthropometric characteristics, 3) labor and delivery experience, 4) newborn characteristics, 5) maternal postpartum factors, and 6) infant feeding variables. We examined independent associations by using multivariable logistic regression analysis., Results: Median OL was 68.9 h postpartum; 44% of mothers experienced delayed OL. We observed significant bivariate associations between delayed OL and variables in all 6 dimensions (P < 0.05). In a multivariate model adjusted for prenatal feeding intentions, independent risk factors for delayed OL were maternal age > or =30 y, body mass index in the overweight or obese range, birth weight >3600 g, absence of nipple discomfort between 0-3 d postpartum, and infant failing to "breastfeed well" > or =2 times in the first 24 h. Postpartum edema was significant in an alternate model excluding body mass index (P < 0.05)., Conclusions: The risk factors for delayed OL are multidimensional. Public health and obstetric and maternity care interventions are needed to address what has become an alarmingly common problem among primiparas.

Deficiencies of multiple micronutrients (MMN) usually coexist in developing countries, but supplements have usually provided only 1 or 2 micronutrients (MN). To inform policy, in this article we compared the relative benefits of supplying MMN vs. a placebo or 1 or 2 MN on the following: children's growth, health, and development; pregnancy outcome; nutritional status; and HIV/AIDS mortality and morbidity in adults. Sufficient data were available to perform random-effects meta-analyses of randomized controlled trials (RCT) for the effects of MMN on child growth and nutritional status. Results for other outcomes are presented as effect sizes (ES) when available. In children, MMN interventions resulted in small but significantly greater improvements in length or height (ES = 0.13; 95% CI: 0.055, 0.21) and weight (ES = 0.14; 95% CI: 0.029, 0.25), hemoglobin (ES = 0.39; 95% CI: 0.25, 0.53), serum zinc (ES = 0.23; 95% CI: 0.18, 0.43), serum retinol (ES = 0.33; 95% CI: 0.050, 0.61), and motor development. A Cochrane review reported that compared with no supplementation or a placebo, MMN supplementation during pregnancy reduced the relative risk of low birth weight (0.83), small-for-gestational age (0.92), and anemia (0.61); however, MMN were not more effective than iron + folic acid alone. There is some evidence that MMN supplementation improves CD4 counts and HIV-related morbidity and mortality in adults. The efficacy of MMN varies across trials, but overall there is evidence that outcomes are better than when providing < or =2 MN. The policy implications of these studies are discussed.

Background: Information is needed on the minimum energy density and feeding frequency of complementary foods that can provide adequate energy intakes (EIs) for healthy breastfed children., Objectives: The objectives of the study were to evaluate the effects of various energy densities and feeding frequencies of complementary foods on EI from these foods, breast milk consumption, and total EI from both sources., Design: During 9 separate, randomly ordered dietary periods lasting 3-6 d each, we measured intakes of food and breast milk by 18 healthy breastfed children 8-11 mo of age who, 3, 4, or 5 times/d, were fed porridge with a coded energy density of 0.5, 1.0, or 1.5 kcal/g. Food intake was measured by weighing the feeding bowl before and after meals, and breast milk intake was measured by test weighing., Results: The mean amounts of complementary foods consumed were inversely related to their energy density and positively related to the number of meals/d (P < 0.001 for both); EIs from foods were positively related to both factors. Breast milk intake decreased slightly but progressively, with greater energy density and feeding frequency of complementary foods; total EIs (kcal/d) increased in relation to both factors (P < 0.001 for both)., Conclusions: The energy density and feeding frequency of complementary foods affect infants' total daily EI and breast milk consumption. Recommendations can be developed for the appropriate combinations of these dietary factors that are compatible with adequate EI, although longer-term effects of complementary feeding practices on breast milk intake and breastfeeding duration need further community-based studies.

Background: No studies have examined the independent effects of current and longer-term dietary zinc intakes on zinc absorption., Objective: We determined the effects of current compared with longer-term zinc intake on fractional zinc absorption (FZA)., Design: 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., Results: Plasma and urinary zinc did not vary by dietary period. Mean FZA was greater from low-zinc meals than from adequate-zinc meals (60.9% +/- 13.8% compared with 36.1% +/- 8.9%; P < 0.0001), whereas mean total absorbed zinc was greater from adequate-zinc meals than from low-zinc meals (3.60 +/- 0.91 compared with 2.48 +/- 0.56; P < 0.0001), regardless of the longer-term dietary period., Conclusions: FZA was inversely related to current zinc intake, but there was no detectable effect of longer-term dietary zinc. If longer- term zinc intake does modify FZA, such changes are smaller than those caused by current zinc intake, or they occur only after more severe zinc depletion.

Background: Information is needed on the fractional absorption of zinc (FAZ) and absorbed zinc (AZ) during prolonged exposure to zinc-fortified foods., Objective: The objective was to measure FAZ and AZ from diets fortified with different amounts of zinc and to determine whether zinc absorption changes over approximately 7 wk., Design: Forty-one stunted, moderately anemic children received daily, at breakfast and lunch, 100 g wheat products fortified with 3 mg Fe (ferrous sulfate) and 0 (group Zn-0), 3 (group Zn-3), or 9 (group Zn-9) mg Zn (zinc sulfate) per 100 g flour. FAZ was measured on days 2-3 and 51-52; meal-specific AZs were calculated as the product of FAZ and zinc intake., Results: For the breakfast and lunch meals combined, mean total zinc intakes were 2.14, 4.72, and 10.04 mg/d in groups Zn-0, Zn-3, and Zn-9, respectively, during the initial absorption studies; mean (+/-SD) FAZ values were 0.341 +/- 0.111, 0.237 +/- 0.052, and 0.133 +/- 0.041, respectively, on days 2-3 (P < 0.001) and did not change significantly on days 51-52 in the subset of 31 children studied twice. Mean initial AZ was positively related to zinc intake (0.71 +/- 0.18, 1.11 +/- 0.21, and 1.34 +/- 0.47 mg/d, respectively; P < 0.001); final values did not differ significantly from the initial values., Conclusions: AZ from meals containing zinc-fortified wheat products increases in young children relative to the level of fortification and changes only slightly during approximately 7-wk periods of consumption. Although consumption of zinc-fortified foods may reduce FAZ, zinc fortification at the levels studied positively affects total daily zinc absorption, even after nearly 2 mo of exposure to zinc-fortified diets.