Track topics on Twitter Track topics that are important to you
Pharmacokinetics is the term used for how the body affects a drug once it is taken. Vitamin C, also known as ascorbic acid, is an essential water soluble vitamin. Meaning, the body does not make Vitamin C it must be taken in through the diet. In this study researchers will attempt to determine how the amount of water consumed affects the level of vitamin C in the blood (specifically the plasma component of the blood).
In this study researchers will take 13 subjects and place them on a Vitamin C restricted diet. Vitamin C levels will be measured twice a week on an outpatient basis until all subjects reach a desired low level of Vitamin C (12-15 micromolar plasma ascorbic acid concentration). Subjects will then be admitted and undergo 24 hour blood and urine collection. Following the collection of samples, subjects will then begin to receive Vitamin C orally (by mouth) and intravenously (injected into the vein). The dosage of Vitamin C will gradually increase from 30 mg-2500 mg divided into two daily doses. Blood and urine samples will be collected each time the dose is increased. The study will take approximately 18 weeks after which the subjects will be discharged in healthy condition....
Vitamin C is an essential water soluble vitamin. To date there have been no carefully controlled clinical trials to demonstrate how changes in vitamin C concentration in human plasma vary as a direct function of the amount ingested over a wide range. In this study, we plan to achieve a prescorbutic vitamin C plasma concentration of approximately 12-15 micromolar in thirteen healthy human volunteers and gradually replete these subjects with incremental doses of vitamin C to measure how their plasma concentrations will change as a function of the dose.
We will induce vitamin C deficiency in the outpatient setting by having volunteers adhere to a vitamin C restricted diet. As inpatients they will be placed on a more tightly restricted scorbutic diet. Plasma vitamin C will be monitored several times per week. When subjects have achieved a plasma AA concentration of 12-15 micromolar, blood sampling and urine collection over 24 hours will be performed. After platelets and leukocytes are collected, AA repletion will begin. Escalating doses of AA will be administered orally and intravenously for the remainder of their inpatient admission. Total daily doses of 30mg, 60mg, 100mg, 200mg, 400mg, 1000mg and 2500mg will be given in two divided doses. Bioavailability of AA will be determined at each dosage increment. When plasma AA concentration reaches steady state for each dose, subjects will undergo 36 hr plasma AA sampling and a timed 48 hr urine collection. At steady state of each of 4 to 5 doses, an apheresis procedure will be performed for collection of platelets and leukocytes. It is anticipated subjects will be discharged in healthy condition after 18 weeks.
National Institutes of Health Clinical Center, 9000 Rockville Pike
Active, not recruiting
National Institutes of Health Clinical Center (CC)
Published on BioPortfolio: 2014-08-27T03:59:40-0400
Healthy Together is a program that promotes the achievement and maintenance of healthy weights in children and their families.
Investigators conducted a pilot feasibility and acceptability randomized controlled trial of a remotely delivered behavioral health coaching program in pregnancy and postpartum.
Absorption, distribution, metabolism, and excretion (ADME) study with 14C in healthy young men.
The purpose of this study is to understand how consuming healthy cookies every day for two weeks will affect different types of fat in the blood. Specifically, the overall goal of this stu...
To assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of IMA-026 administered subcutaneously (SC) or intravenously (IV) in healthy adults.
Using an operational continuum of healthy aging developed by U.S. researchers, we sought to estimate the prevalence of healthy aging among older Spaniards, inform the development of a definition of he...
The American Nurses Association declared 2017 the Year of the Healthy Nurse. In an effort to promote a healthy academic environment, faculty and staff in institutions of higher learning should serve a...
China has the largest population in the world, and its health levels have greatly affected the healthy development of the population of the world. Healthy China 2030 is a breakthrough for ensuring tha...
Across Ontario, the Healthy Babies Healthy Children (HBHC) postpartum screening tool is routinely used to identify families with potential risk of negative development outcomes for children.
Sequence-specific learning (SSL); the ability to implicitly integrate repeated sequences compared to random sequences during a motor sequence paradigm, is impaired in healthy elders (HE) compared to h...
Healthy People Programs are a set of health objectives to be used by governments, communities, professional organizations, and others to help develop programs to improve health. It builds on initiatives pursued over the past two decades beginning with the 1979 Surgeon General's Report, Healthy People, Healthy People 2000: National Health Promotion and Disease Prevention Objectives, and Healthy People 2010. These established national health objectives and served as the basis for the development of state and community plans. These are administered by the Office of Disease Prevention and Health Promotion (ODPHP). Similar programs are conducted by other national governments.
Governmental guidelines and objectives pertaining to public food supply and nutrition including recommendations for healthy diet and changes in food habits to ensure healthy diet.
Surgical reinnervation of a denervated peripheral target using a healthy donor nerve and/or its proximal stump. The direct connection is usually made to a healthy postlesional distal portion of a non-functioning nerve or implanted directly into denervated muscle or insensitive skin. Nerve sprouts will grow from the transferred nerve into the denervated elements and establish contact between them and the neurons that formerly controlled another area.
Process of evaluating the health of a patient and determining if they are healthy enough for surgery.
Dietary patterns which have been found to be important in reducing disease risk.
Pharmacy is the science and technique of preparing as well as dispensing drugs and medicines. It is a health profession that links health sciences with chemical sciences and aims to ensure the safe and effective use of pharmaceutical drugs. The scope of...
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...
Blood is a specialized bodily fluid that delivers necessary substances to the body's cells (in animals) – such as nutrients and oxygen – and transports waste products away from those same cells. In vertebrates, it is composed of blo...