Journal of Nutrition Nutrient Requirements and Optimal Nutrition

Epidermal Growth Factor-Expressing Lactococcus lactis Enhances Intestinal Development of Early-Weaned Pigs [Nutrient Requirements and Optimal Nutrition]

Kang, P., Toms, D., Yin, Y., Cheung, Q., Gong, J., De Lange, K., Li, J. — Fri, 19 Mar 2010 09:01:15 PDT

Stress and incomplete gastrointestinal development in early-weaned piglets represent significant challenges in commercial swine farming. Orally ingested recombinant epidermal growth factor (EGF) has been shown to remain biologically active in the gastrointestinal tract as well as stimulate intestinal development, reducing the incidence of pathogen infection and diarrhea. We have previously shown that the food-grade bacterium Lactococcus lactis can be genetically altered to express biologically active EGF when fed to early-weaned mice. In this study, we assigned 8 pigs to each of 4 groups that were given EGF-expressing L. lactis (EGF-LL), empty vector-expressing L. lactis (EV-LL), recombinant human EGF, or unsupplemented bacterial media, all of which were delivered as 50-mL i.g. doses twice per day. All pigs were killed after 14 d to examine intestinal morphology. Pigs in the EGF-LL group had greater jejunal and duodenal villus heights (P < 0.0001) and intestinal length (P = 0.049) than pigs in the control group. Immunohistochemistry with antibodies against proliferating cell nuclear antigen (PCNA) revealed that the proliferation of intestinal cells was significantly greater in the EGF-LL group than in the control group. PCNA expression and intestinal length also were greater in the EV-LL group, which received L. lactis that did not express EGF, than in the control group (P = 0.049), further supporting the use of naturally occurring intestinal microbes as desirable vectors for recombinant protein delivery. Our data demonstrates the feasibility of delivering a growth factor using common probiotic bacteria to farm animals for commercial practice.

Vitamin D Intake Needed to Maintain Target Serum 25-Hydroxyvitamin D Concentrations in Participants with Low Sun Exposure and Dark Skin Pigmentation Is Substantially Higher Than Current Recommendations [Nutrient Requirements and Optimal Nutrition]

Fri, 19 Feb 2010 09:01:12 PST

Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake. Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7–8 wk in the fall, winter, spring, and summer in Davis, CA [38.5° N, 121.7° W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R² = 0.55; P < 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, ~20 min/d, ~18% body surface area (BSA) exposed] and high (80th percentile, ~90 min/d, ~35% BSA exposed) sun exposure, assuming an intake of 200 iu/d (5 ug/d). Predicted serum 25(OH)D concentrations for AA individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D ≥75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 iu/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100–3100 iu/d year-round.

Vitamin D Supplement Consumption Is Required to Achieve a Minimal Target 25-Hydroxyvitamin D Concentration of >=75 nmol/L in Older People [Nutrient Requirements and Optimal Nutrition]

Barake, R., Weiler, H., Payette, H., Gray-Donald, K. — Fri, 19 Feb 2010 09:01:12 PST

Population level data on how older individuals living at high latitudes achieve optimal vitamin D status are not fully explored. Our objective was to examine the intake of vitamin D among healthy older individuals with 25-hydroxyvitamin D [25(OH)D] concentrations ≥75 nmol/L and to describe current sources of dietary vitamin D. We conducted a population-based, cross-sectional study of 404 healthy men and women aged 69 to 83 y randomly selected from the NuAge longitudinal study in Québec, Canada. Dietary intakes were assessed by 6 24-h recalls. We examined the contribution of foods and vitamin/mineral supplements to vitamin D intake. Serum 25(OH)D was assessed by RIA. We assessed smoking status, season of 25(OH)D measurement, physical activity, and anthropometric and sociodemographic variables. Vitamin D status was distributed as follows: 7% (<37.5 nmol/L), 48% (37.5–74.9 nmol/L), and 45% (≥75 nmol/L). Vitamin D intake from supplements varied across the 3 vitamin D status groups: 0.5, 4.1, and 8.9 µg/d, respectively (P < 0.0001). Adding food sources, these total intakes were 4.6, 8.7, and 14.1 µg/d, respectively. In multivariate analysis, vitamin D from foods and supplements and by season was associated with vitamin D status. These healthy, community-dwelling older men and women with 25(OH)D concentrations >75 nmol/L had mean intakes of 14.1 µg/d from food and supplements. Supplement use is an important contributor to achieve a minimal target of 25(OH)D concentration ≥75 nmol/L.

Maternal Folate and Cobalamin Status Predicts Vitamin Status in Newborns and 6-Month-Old Infants [Nutrient Requirements and Optimal Nutrition]

Fri, 19 Feb 2010 09:01:12 PST

Our aim in this longitudinal study was to determine predictors of folate and cobalamin status in infancy. Data were collected from 364 mother-infant pairs with blood measurements from pregnancy (~18 wk; n = 149), newborns (cord serum; n = 361), and 6-mo-old partially or exclusively breast-fed children (n = 221). Serum/plasma folate, cobalamin, holotranscobalamin (holoTC), holohaptocorrin (holoHC), methylmalonic acid (MMA) and total homocysteine (tHcy) at birth and 6 mo were related to maternal vitamin status, parity, lifestyle variables, and anthropometry. In multivariate analyses, the strongest predictors of folate at birth and 6 mo were maternal folate and cord folate, respectively (P < 0.01). Maternal holoTC best predicted cobalamin status at birth (positively associated with cord cobalamin, holoTC, and holoHC; inversely with MMA and tHcy; P ≤ 0.001), whereas maternal and cord holoHC were the strongest predictors of cobalamin status at 6 mo (positively associated with cobalamin, holoTC, holoHC; inversely with tHcy; P < 0.05). The association between cobalamin status and parity was negative at birth but positive at 6 mo. Birth weight, female sex, and smoking were associated with low cobalamin or high tHcy at birth but showed no or opposite associations at 6 mo. In conclusion, maternal folate and cobalamin status exerts a long-term positive effect on infant vitamin status. The effect of smoking, parity and female sex on cobalamin status did not persist beyond the newborn period. Maternal holoTC was the superior predictor of newborn cobalamin status, while holoHC could be a valuable marker for predicting cobalamin status later in infancy.

Estimation of Antioxidant Intakes from Diet and Supplements in U.S. Adults [Nutrient Requirements and Optimal Nutrition]

Chun, O. K., Floegel, A., Chung, S.-J., Chung, C. E., Song, W. O., Koo, S. I. — Wed, 20 Jan 2010 09:03:14 PST

The importance of antioxidants in reducing risks of chronic diseases has been well established; however, antioxidant intakes by a free-living population have not yet been estimated adequately. In this study, we aimed to estimate total antioxidant intakes from diets and supplement sources in the U.S. population. The USDA Flavonoid Database, food consumption data, and dietary supplement use data of 8809 U.S. adults aged ≥19 y in NHANES 1999–2000 and 2001–2002 were used in this study. Daily total antioxidant intake was 208 mg vitamin C (46 and 54% from diets and supplements, respectively), 20 mg -tocopherol (36 and 64), 223 µg retinol activity equivalents carotenes (86 and 14), 122 µg selenium (89 and 11), and 210 mg flavonoids (98 and 2). Antioxidant intakes differed among sociodemographic subgroups and lifestyle behaviors. Energy-adjusted dietary antioxidant intakes were higher in women, older adults, Caucasians, nonconsumers of alcohol (only for vitamin C and carotenes), nonsmokers (only for vitamin C, vitamin E, and carotenes), and in those with a higher income and exercise level (except for flavonoids) than in their counterparts (P < 0.05). Consumption of fruits, vegetables, and whole grains may be a good strategy to increase antioxidant intake. The possible association between antioxidant intake and the prevalence of chronic diseases should be investigated further.

Iron-Fortified Rice Is As Efficacious As Supplemental Iron Drops in Infants and Young Children [Nutrient Requirements and Optimal Nutrition]

Beinner, M. A., Velasquez-Melendez, G., Pessoa, M. C., Greiner, T. — Fri, 18 Dec 2009 09:01:33 PST

How to improve iron status among infants and young children is of continued concern in low- to middle-income countries, including Brazil. In a double blind, 5-mo, home-based, randomized trial in Brazil, we gave one group of mildly anemic 6- to 24-mo-old children (n = 175) rice fortified with micronized ferric pyrophosphate using the Ultra Rice technology and a placebo solution (URG) and another group identical nonfortified rice and iron drops. We instructed parents on the correct dosage of iron drops and to feed their children rice as they normally would. We measured serum ferritin (SF) and hemoglobin (Hb) concentrations at baseline and at 5 mo. At baseline, the prevalences of iron deficiency and anemia in the total sample were 73.1 and 100%, respectively. At 5 mo, SF and Hb increased in both groups, although the change in the URG was larger (P < 0.01). Adult participants were unable to distinguish cooked fortified rice from unfortified rice in terms of smell, color, or taste. As rice is normally consumed at home, MPF-fortified rice increased iron stores and reduced anemia in a group of mildly anemic children 6–24 mo old. In populations where young children are routinely fed ~100 g of cooked rice daily, fortifying it with iron may improve iron status at least as well as providing free iron drops.

Lysine Requirement of Healthy, School-Aged Indian Children Determined by the Indicator Amino Acid Oxidation Technique [Nutrient Requirements and Optimal Nutrition]

Fri, 18 Dec 2009 09:01:33 PST

We recently reported the lysine requirement of school-aged children living in Canada consuming a mixed diet to be 35 mg·kg^–1·d^–1. Because the majority of children in the world live on cereal-based diets in developing countries, we measured the daily lysine requirement in healthy children living in India and consuming a mostly cereal-based diet. Our objective in this study was to determine the lysine requirement in healthy, school-aged children in the developing world by using the indicator amino acid oxidation method with l-[1-¹³C] phenylalanine. Six healthy, school-aged children consumed 7 levels of lysine (5, 15, 25, 35, 50, 65, and 80 mg·kg^–1·d^–1) each in a random order along with an amino acid mixture providing energy and protein intakes of 1.7 x resting energy expenditure and 1.5 g·kg^–1·d^–1, respectively. The mean lysine requirement was determined by applying a 2-phase linear regression crossover analysis on tracer oxidation (F¹³CO₂) data, which identified a breakpoint (requirement) at minimal F¹³CO₂ in response to the graded lysine intakes. The mean lysine requirements with the upper 95% CI for children were determined to be 33.5 and 46.6 mg·kg^–1·d^–1, respectively, by breakpoint analysis of the F¹³CO₂ data. The mean lysine requirements of Indian children were almost identical to that of Canadian children (35 mg·kg^–1·d^–1). There is no evidence for any adaptation in lysine requirements in children from developing countries such as India.