14 Clinical Trials for Various Conditions
The purpose of this study is to determine the effects of consuming a small breakfast of juice and toast with added phytate or with taking a folic acid supplement on the absorption of a small amount of zinc that is either bound to amino acids or to chloride or picolinate. The results of this study will provide new information on how components of diet (e.g., phytate, and folic acid) affect the absorption of different forms of dietary zinc (e.g., zinc bound to amino acids, zinc chloride, and zinc picolinate).
The goal of our research is to provide data to enhance the development of nutritional guidelines, especially as related to mineral nutrition, in children. Using human experimentation, we are studying methods of delivering the key minerals of calcium, zinc and iron in the diet so as to optimize health outcomes. We will conduct a controlled trial of vitamin D supplementation to assess the effects of vitamin D status on calcium absorption in small children. We will evaluate the effects of differing intakes of zinc on zinc and copper absorption. These studies will utilize stable isotope techniques so as to provide accurate, practically applicable information which may be obtained from the study populations in a safe manner. These data will have global application and provide a strong basis for evidence-based nutritional recommendations to be developed. Objective #1: To evaluate the effects of supplemental vitamin D in enhancing calcium absorption in healthy children 4 to 8 yrs of age. Objective #2: Assess the absorption of magnesium and zinc in healthy children 4 to 8 yrs of age.
This study is determine the effects of dietary calcium and phytate on zinc absorption.
Fifteen female study participants will be enrolled in a randomized crossover study to measure fractional and total zinc and iron absorption from four common bean (Phaseolus vulgaris) varieties with varying phytate and polyphenolic contents. Phytate, the storage form of phosphorus in plants, and polyphenols, which contribute to the varied colors of common beans, are natural components of the beans and can reduce zinc and iron bioavailability from these foods.
Zinc may be absorbed from diet via zinc transporter mediated pathways, or, when coupled with amino acids, via amino acid transporter pathways. When zinc is coupled with amino acids in diet, it may dissociate from those amino acids in the acidic environment of the stomach prior to entering the small intestine. An experimentally-determined value for any pre-absorptive dissociation of zinc from a zinc amino acid complex (ZnAA) is necessary for the accurate compartmental modeling of zinc metabolism when provided as ZnAA compared with ionic zinc, which the investigators will perform in a future study. The current study will allow us to determine the dissociation of zinc from ZnAA, while serving as a pilot test of a novel technique to determine for the first time an individual's zinc transport kinetics.
The overall objective is to determine the impact of EED on total daily zinc absorption of young Bangladeshi children (18-24 months of age) in an austere setting with high rates of diarrhea, stunting, and micro-nutrient deficiencies..
The objective of this study is to compare the quantity of Zn absorbed from an accurately weighed quantity (\~100 g) of minimally milled control maize (\~15 µg Zn/g maize), from biofortified maize (\~30 µg Zn/g) and from the same control maize that has been fortified (total level of \~60 µg Zn/g) when fed to young children age 24-36 months whose major habitual food staple is maize.
Bioavailability of iron and zinc from habitual plant-based diets consumed by young children in Mexico is low due to the high phytate content. Whey protein has been found to increase zinc absorption, thus, providing a whey based supplement with micronutrients may be an effective strategy to increase iron and zinc bioavailability from plant-based foods and alleviate iron and zinc deficiencies. The investigators compared absorption of zinc and iron in children receiving diets with and without whey protein supplements (WPS).
Young children in Guatemala are at risk for nutrient deficiencies due to plant-based diets and poor sanitation. Stunting, frequent diarrhea, and respiratory infections are common. Supplementation of Zn to children during diarrhea episodes has been shown to diminish duration and severity of illness. Poor Zn absorption due to high fiber and phytate in this diet might play a role in these processes. Supplementation of this micronutrient in the diet might be beneficial. The investigators will compare absorption of Zn from white maize tortillas enriched with 20% amaranth to traditional white corn tortillas in preschool children in Guatemala.
The investigators propose to study the effects of increased iron intake by home fortification of complementary foods on the gastrointestinal microbial development, inflammatory responses, and zinc (Zn) absorption. The proposed subjects are 9 month olds living in a malaria endemic area of rural Kenya who are randomized at 6 months of age to one of three fortificant groups: 1) Sprinkles™ with 12mg Iron(Fe)/day + other micronutrients, including 5mg/d Zn (test); Sprinkles™ with 0 mg/d Fe + other micronutrients, including 5mg/d Zn (control); Sprinkles™ with no micronutrients (placebo). The investigators hypothesize that the microbiome will be significantly different in the three groups and that Zn absorption and status, in addition to immune and oxidant status will be improved in the non-Fe fortified groups when compared to the Fe-fortified group.
Populations who consume non-fortified plant-based diets are at increased risk of iron and zinc deficiencies. The purpose of this randomized controlled study is to determine the absorption of iron and zinc from pearl millet biofortified with these two micronutrients. Forty children aged 2 years in Kanartaka, India are randomized to consume biofortified pearl millet (Group 1) or control pearl millet (Group 2) for two days. Quantities of zinc and iron absorbed are measured with established stable isotope extrinsic labeling techniques and analyses of duplicate diets.
Zinc deficiency has occasionally been reported in CF, but the need for additional zinc is unclear. We will examine the effect of additional zinc supplements on zinc absorption, zinc excretion, zinc balance and zinc kinetics in children with CF. Twelve children with CF will receive additional zinc, and twelve will not. We will also compare the children with CF to 12 healthy children without CF. We hypothesize that children with CF will have poor zinc absorption and high zinc excretion, leading to poor zinc balance and abnormal zinc kinetics. We hypothesize that those children with CF who are given zinc supplements will have higher zinc balance and more normal zinc kinetics than those without supplementation, and that zinc balance and zinc kinetics will be similar to healthy children.
We propose to examine the absorption and excretion of zinc and copper in infants with ostomies. This will be accomplished by measuring baseline excretion and serum levels of zinc, copper, and ceruloplasmin, and by utilizing stable isotopes of zinc and copper to measure absorption and excretion. To determine how the presence of an ileostomy impacts zinc and copper metabolism in infants at three time points: 1) when the infant has an ostomy and is receiving the majority of calories from total parenteral nutrition (TPN); 2) when the infant has an ostomy and is receiving primarily enteral nutrition without TPN; and 3) when/if the infant has a surgery to reconnect the bowel and is receiving primarily enteral nutrition. For the first part of the study, excretion data for zinc will be obtained for ostomy patients. We hypothesize that infants with an ostomy will excrete more zinc in their stools than healthy term or preterm infants without ostomies. For the second part of the study, we will obtain data on zinc absorption, secretion, and excretion through use of stable isotopes. Jalla et al determined that healthy infants retain zinc of 0.4 mg/day. We hypothesize that due to increased zinc losses, the infants in the study will be less positive than the healthy infants in the study by Jalla et al. Our study is designed to be able to detect if the ostomy patients net retention is one-half that described by Jalla (i.e. 0.2 mg/d). We will also obtain data on copper absorption, secretion, and excretion through the use of stable isotopes in the second part of the study. As a pilot study, we do not fully know what to expect regarding copper levels in infants with ostomies, but we hypothesize that they may be less positive than healthy infants without ostomies. Also, we hypothesize that zinc and copper are competitively absorbed in the gut; therefore, infants who receive more zinc may absorb less copper. For the third part of the study, we will obtain data on zinc absorption through the use of stable isotopes after the infant has had surgery to reanastomose the bowel. We hypothesize that there may be continued zinc losses above those documented for healthy infants who have never had an ostomy, but decreased losses compared to when the infant had an ostomy.
The overall objective is to determine the impact of EED on zinc absorption and homeostasis, and its impact on the absorptive capacity of vitamin A absorption of young children (18-24 months of age) in an austere setting with high rates of diarrhea, stunting, and micro-nutrient deficiencies.