Location: Jean Mayer Human Nutrition Research Center On Aging
Project Number: 8050-51000-092-000-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2014
End Date: May 15, 2019
Objective:
LAB Name: Bone Metabolism
1. Determine the effects of dietary and supplemental vitamin D and related nutrients in the prevention and progression of musculoskeletal performance and dysfunction, glucose homeostasis and type 2 diabetes, and other chronic diseases.
1.A. The impact of supplemental vitamin D on serum 25-hydroxyvitamin D (25OHD) levels and short-term indicators of physical function.
1.B. Determine the impact of vitamin D3-omega3-home exercise on aging.
1.C. Determine the effect of supplemental vitamin D on incident of diabetes in subjects with pre-diabetes.
1.D. Determine the effect of supplemental vitamin D on glucose tolerance in subjects with established diabetes.
2. Determine the effects of dietary acid-base balance on bone and muscle metabolism and function.
2.A. Conduct a dose-finding trial of the musculoskeletal benefits of bicarbonate in older adults.
3. Define the contributions of vitamin D absorption, metabolism, and genetic variation in regulating the circulating levels of 25-hydroxyvitamin D and other metabolites.
3.A. Conduct a pilot study of the effect of dietary fat type and amount on vitamin D3 absorption.
LAB NAME: Vitamin K
1: To characterize dietary factors, including food composition and nutrient-nutrient interactions, and non-dietary factors, such as genetics, that contribute to the inter-individual variation in vitamin K intake, bioavailability, and utilization and vitamin K metabolite production.
1.1: To study the influence of foods and single nutrients on the distribution, bioavailability and function of different forms of vitamin K and their metabolites.
1.2: To measure key foods to monitor changes in the food supply that affect vitamin K content
1.3: Identify genetic factors involved in vitamin K metabolism.
2: Determine the role(s) and mechanism(s) of action for vitamin K beyond its essential role in coagulation, including the role of vitamin K in the prevention of abnormal non-skeletal calcification and the mechanisms of vitamin K action not currently explained by its role as an enzyme cofactor.
2.1: Determine the effects of vitamin K in the prevention of abnormal non-skeletal calcification and other chronic diseases in older adults.
2.2: Identify potential mechanism(s) of vitamin K action that are not currently explained by its role as an enzyme cofactor.
Approach:
LAB Name: Bone Metabolism
This laboratory uses a variety of approaches to carry out its clinical and translational research program, including cross-sectional and observational studies, randomized intervention trials, and small metabolic studies. This laboratory collaborates with the Nutrition, Exercise Physiology and Sarcopenia Laboratory to examine the impact of vitamin D and the acid-base balance of the diet on muscle performance and risk of falling. In collaboration with external laboratories, this laboratory seeks to determine the impact of vitamin D on risk of developing type 2 diabetes. These and other collaborations allow us access to basic research technologies, such as muscle tissue histology and gene array analysis, that enable us to identify mechanisms by which nutrients affect bone and muscle.
LAB NAME: Vitamin K
Our long-term objective is to study the determinants of vitamin K bioavailability, utilization, and metabolism in order to refine vitamin K intake recommendations. Expansion of the forms of vitamin K analyzed in a selected number of foods will enhance the USDA vitamin K database, and allow us to monitor changes in different forms of vitamin K in the food supply. To identify dietary and non-dietary factors that determine how much vitamin K obtained from foods is utilized, we will apply stable isotope techniques to established and novel measures of vitamin K metabolism. Data obtained from our completed metabolic study in younger and older adults, in addition to animal studies, have helped to refine the study designs that will be used in this project plan. We will initiate a series of studies that compare the metabolism of different forms of vitamin K, and identify the impact of other nutrients on different aspects of vitamin K metabolism. To expand our observations that vitamin K may have a role in the prevention of abnormal non-skeletal calcification, we will use observational data and biological samples collected from large on-going cohorts, as well as conduct animal studies, to examine potential mechanisms beyond that of an enzyme cofactor. We will then focus on the role(s) of different forms of vitamin K in insulin resistance and inflammation using a rodent model. This is a rapidly evolving field, and novel functions of vitamin K in other cells will be considered as new information becomes available.
