Location: Obesity and Metabolism Research Unit
2010 Annual Report
OBJECTIVE 1: Determine the effects of specific foods, fortified foods, and nutrients on bone health of at-risk population groups. Sub-objective 1.A. Determine the effects of carbonated beverages and milk on calcium kinetics and calcium efflux from the skeleton of women and girls (Van Loan, Allen, and Huang). Sub-objective 1.B. Determine the effects of vitamin B12 deficiency on markers of calcium kinetics, bone health, and calcium metabolism in postmenopausal women (Allen, Van Loan).
OBJECTIVE 2: Investigate vitamin B12 and zinc intestinal absorption and metabolism in at-risk populations. Sub-objective 2.A. Determine the absorption of 14C-vitamin B12 from fortified foods in elderly with gastric atrophy and H. pylori infection, pre- and post H. pylori treatment (Allen, Huang). Sub-objective 2.B. Determine the impact of SNPs in a major Zn uptake gene (ZIP4) on dietary Zn absorption using ZIP4-expressing cell lines. (Huang, Allen).
OBJECTIVE 3. Investigate the effect of Zn supplementation on the development of prostate cancer, a cancer common in African-Americans, using a mouse prostate cancer model (TRAMP) (Huang).
Effects of Vitamin B12 Deficiency on Markers of Calcium Kinetics had 3 women complete the full protocol. Absorption of 14C-Vitamin B12 from Fortified Foods in Elderly with Gastric Atrophy and H. Pylori Infection, Pre- and Post H. Pylori Treatment continues to encounter difficulty recruiting volunteers; 5 control subjects are complete, but no subjects with gastric atrophy have been enrolled. Several studies have been designed to examine improvement in nutritional status of individuals following dietary or supplemental interventions. These studies include: Effect of Animal Source Foods on Vitamin and Mineral Status in Kenya continues to evaluate micronutrient status in Kenyan women and their children; Vitamin and Mineral Supplementation in Children investigates effect of vitamin and mineral supplementation in children in rural Honduras; Vitamin B12 Supplementation in Elderly Chileans is determining benefits of vitamin B12 supplements or vitamin B12 fortified milk for neurological and cognitive function; and Lipid-Based Micronutrient Supplement for Infants and Lactating Women examines improvement of vitamin and mineral status in lactating women and their infants given a micronutrient-rich lipid-based supplement. The Impact of SNPs in a Major Zn uptake Gene (ZIP4) on dietary Zn absorption using ZIP4-expressing cell lines has been studied using glycosylation, trafficking, and degradation assays. Data analysis and manuscript submission were accomplished. The study demonstrated that single nucleotide polymorphisms (SNPs; single changes in the genetic code that alter ZIP4 protein) did not change the rate of zinc uptake in yeast and human cell models. This study indicates that while ZIP4 sequences differ across the population, known changes in the sequence do not appear important to regulating zinc homeostasis.
The effect of Zn supplementation on the development of prostate cancer has shown in mice that a mutation of the zinc transporter protein Znt7-null promotes prostate cancer progression. Early onset of prostate cancer and aggressive progression of the prostate cancer seen in TRAMP/Znt7-/- mice were due to the combination of increased cell proliferation and decreased cell apoptosis of Tag-expressing epithelial cells in the prostate of TRAMP/Znt7-/- mice. Results highlight the importance of maintaining normal prostate tissue zinc status to thwart cancer progression.
Allen, L.H. Pregnancy and lactation. Present Knowledge in Nutrition Book Chapter. AG-PPKN-0909 R1 CH41 03-31-06 10:28:43
Allen, L.H. 2009. How common is vitamin B12 deficiency? American Journal of Clinical Nutrition. 89:693S-696S.
Lildballe, D.L., Hardlei, T.F., Allen, L.H., Nexo, E. 2009. High concentrations of haptocorrin interfere with routine measurement of cobalamins in human serum and milk. A problem and its solution. Clin. Chem. Lab Med., 47:182-187.
Mclean, E.D., Allen, L.H., Neumann, C.G., Peerson, J.M., Siekmann, J.H., Murphy, S.P., Bwibo, N.O., Demment, M.W. 2007. Low plasma vitamin B-12 in Kenyan school children is highly prevalent and improved by supplemental animal source foods. Journal of Nutrition. 137:676-682, 2007.
Allen, L.H., Kerstetter, J.E. Calcium. Encyclopedia of Human Nutrition. 2005, Elsevier Ltd. 253-259.
Allen, L.H., Graham, J.M., Sabel, J.E. Dietary guidelines and safe supplement use. Encyclopedia of Human Nutrition. 2005 Elsevier Ltd. 8-16.
Matvienko, O.A., Alekel, D.L., Genschel, U., Ritland, L., Van Loan, M.D., Koehler, K. 2010. Isoflavones supplements do not, but appetitive hormones do, influence overall and central adiposity in healthy postmenopausal women. The Journal of the North American Menopause Society. Vol. 17, No. 3, pp. 594-601.
Hoffman, M., Lebus, D., Gangong, A., Casazza, G., Van Loan, M.D. 2010. Body Composition Measurements of 161-km Ultramarathon Participants. International Journal of Sports Medicine. 31:106-109.
Stewart, J.W., Alekel, D.L., Ritland, L.M., Van Loan, M.D., Gertz, E.R., Genschel, U. 2009. Serum 25-hydroxyvitamin D is related to indicators of overall physical fitness in healthy postmenopausal women. Menopause. 16:1093-1101.
Lebus, D.K., Casazza, G.A., Hoffman, M.D., Ganong, A.C., Van Loan, M.D. 2010. Changes in Body Mass, Hydration and Electrolytes Following a 161-km Endurance Race. Clinical Journal of Sport Medicine. Vol 20:193-199.