Vanessa da Silva, PhD, RDN, CDCES

Director, UA Cooperative Extension Diabetes Prevention Program (DPP)

Extension Specialist

School of Nutritional Sciences and Wellness


  • Postdoctoral Research, Obesity and Folate Metabolism, University of Georgia
  • PhD, Nutritional Sciences, University of Florida
  • BS, Agricultural and Biological Engineering, University of Florida
  • Registered Dietitian Nutritionist (RDN)
  • Certified Diabetes Care and Education Specialist (CDCES)


Cooperative Extension & Outreach Projects

Diabetes Prevention Program

While 1 in 10 Arizonans have diabetes, 1 in 3 adults have prediabetes, and most don’t know they do. Prediabetes is a condition in which blood sugar is high, but not high enough to be classified as type 2 diabetes. Most people with prediabetes have no symptoms. Prediabetes often progresses to type 2 diabetes. However, it is possible to delay or prevent this progression. Adopting healthier eating behaviors and increasing physical activity can drastically cut the risk of developing diabetes.

The CDC’s National Diabetes Prevention Program is a lifestyle-based intervention offered nationwide in a concerted effort to reduce the prevalence of type 2 diabetes. The program provides 12-months of support from a trained educator (lifestyle coach), in a safe, judgment-free group setting. Classes meet weekly initially, then every other week, and finally once a month.

The University of Arizona Cooperative Extension offers the National DPP across the state, and has obtained FULL PLUS recognition status from the CDC.  Classes are available in-person or over Zoom, in English or in Spanish. At the moment, there is no charge to participate!

Learn more and sign up for a class at

Dining with Diabetes

Diabetes has become a serious concern for the state of Arizona. Approximately 10% of the Arizona adult population, costing the state $6.8 billion a year in direct and indirect medical costs.

Nutrition is an important aspect of type 2 diabetes management, and people with diabetes often struggle with knowing what to eat. Dining with Diabetes is an Extension program that helps people with diabetes or prediabetes learn how to prepare healthier meals that are also delicious. The group classes meet weekly for 4 weeks, with a follow-up meeting 3 to 4 months later.

Click here to be the first to know when a new Dining with Diabetes class starts!


Peer-Reviewed Publications

  • Richardson KM, Schembre, SM; da Silva V, Blew R, Behrens N, Roe D, Marvasti FM, Hingle M. Adding a Brief Continuous Glucose Monitoring Intervention to the National Diabetes Prevention Program: A Multi-Method Feasibility Study. Journal of Diabetes Research, 2024 (pending revisions)
  • Rafie C, Johnson N, Jarvandi S, Berg A, da Silva V, Morrisroe-Aman B, Welshons K. Distance Learning for Delivery of the Diabetes Prevention Program: Experiences of the Cooperative Extension National Diabetes Prevention Program Working Group (CE-NDPP). Journal of the NEAFCS, 2022 Vol 16, pp116-121
  • Reicks M, Banna J, Anderson AK, da Silva V, Gunther C, Hongu NK, Jones B, Lora K, Monroe-Lord L, Richards R, Topham G, Wong SS. Development of Parent and Adolescent Questionnaires to Assess Food Parenting Practices That Address Adolescent Consumption During Independent Eating Occasions. J Nutr Educ Behav. 2019 Nov 25. pii: S1499-4046(19)31095-4.
  • Gunther C, Reicks M, Banna J, Suzuki A, Topham G, Richards R, Jones B, Lora K, Anderson AK, da Silva V, Penicka C, Hopkins LC, Cluskey M, Hongu N, Monroe-Lord L, Wong SS. Food Parenting Practices That Influence Early Adolescents' Food Choices During Independent Eating Occasions. J Nutr Educ Behav. 2019 Sep;51(8):993-1002.
  • Rosputni C., Short E., Sepulveda M., Howe C., da Silva V., Alvarez K., Hingle M. Diabetes prevention programs in rural North America: a systematic scoping review. Curr Diab Rep. 2019 Jun 19;19(7):43
  • Gachupin F, Brown C, Bryant H, da Silva V. Usual Dietary Intake and Adherence to Dietary Recommendations among Southwest American Indian Youth at Risk for Type 2 Diabetes, Curr Dev Nutr. 2019 Oct 9;3(11):nzz111
  • Kurzius-Spencer M, da Silva V, Thomson CA, Hartz V, Hsu CH, Burgess JL, O'Rourke MK, Harris RB. Nutrients in one-carbon metabolism and urinary arsenic methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Science of the Total Environment, 2017; 607-608: 381-390
  • Elmer S, Harrison J, da Silva V. Social media use in the Expanded Food and Nutrition Education Program – the perspective of educators and program participants. Journal of Extension, 2016; 54(3), Article 3FEA5
  • da Silva V, Ralat MA, Quinlivan EP, Chi Y, DeRatt B, Nijhout F, Reed MC, Gregory JF. Targeted metabolomics and mathematical modeling demonstrate that vitamin B-6 restriction alters one-carbon metabolism in cultured HepG2 cells. American Journal of Physiology – Endocrinology and Metabolism, 2014 Jul 1;307(1):E93-101
  • da Silva V, Hausman D., Kauwell, G., Sokolow, A., Tackett, R., Rathbun, S., Bailey, L. Obesity affects short-term folate pharmacokinetics in women of childbearing age. International Journal of Obesity, 2013 Dec;37(12):1608-10
  • da Silva V, Rios-Avila L, Lamers Y, Ralat, MA, Midttun O, Quinlivan E, Garrett TJ, Chi Y, Muller L, Ueland PM, Stacpoole P, Gregory JF. Metabolite profile analysis reveals functional effects of vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women. Journal of Nutrition, 2013 Nov;143(11):1719-27
  • Gregory, JF, Park, Y, Lamers, Y, Bandyopadhyay, N, Chi, Y,  Lee, K, Kim, K, da Silva, V, Hove, N, Ranka, S, Kahveci, T, Muller, K, Stevens, R, Newgard, C, Stacpoole, P, Jones, D. Metabolomic Analysis Reveals Extended Metabolic Consequences of Marginal Vitamin B-6 Deficiency in Healthy Human Subjects. Public Library of Science ONE, 2013; 8 (16)
  • Zhao M, Ralat M, da Silva V, Garrett T, Melnyk S, James S, Gregory JF. Vitamin B-6 restriction impairs fatty acid synthesis in cultured human hepatoma (HepG2) cells. American Journal of Physiology - Gastrointestinal and Liver Physiology, 2013; 304(4):E342-51
  • Benight N, Stoll B, Chacko S, da Silva V, Marini J, Gregory JF, Stabler S, Burrin D. B-vitamin deficiency is protective against DSS-induced colitis in mice. American Journal of Physiology - Gastrointestinal and Liver Physiology. 2011; 301(2):G249-G259
  • Waller JC, Alvarez S, Naponelli V, Lara-Nunez A, Blaby IK, da Silva V, Ziemak MJ, Vickers TJ, Beverley SM, et al. A role for tetrahydrofolates in the metabolism of iron-sulfur clusters in all domains of life. Proceedings of the National Academy of Sciences of the United States of America. 2010 Jun 8;107:10412-7

Peer-Reviewed Cooperative Extension Publications

  • Zilliox P and da Silva V. Folate & Folic Acid – Healthy Moms Mean Healthy Babies.(2017) Arizona Cooperative Extension Publication AZ1733.  
  • Wyatt M and da Silva V. Eating for Two – Healthy Pregnancy Starts with a Healthy Diet. 2017 (accepted)

Book Chapters

  • da Silva, V and Gregory JF. Vitamin B6. Present Knowledge in Nutrition, 11th Edition, volume 1. Eds. Marriott, Bernadette P., Diane F. Birt, Virginia A. Stallings, and Allison A. Yates. Elsevier: Amsterdam, Netherlands, 2020.
  • Bailey, LB, da Silva, V, West, A, Caudill, M. Folate. In: Zempleni, J, Suttie,  JW, Gregory JF, and Stover, PJ, eds. Handbook of Vitamins, Taylor and Francis, 5th edition (2013)
  • da Silva, V, Russell, K, Gregory JF. Vitamin B6. In: Erdman, J, Macdonald, I, Zeisel, S, eds. Present Knowledge in Nutrition. ILSI Press, 10th edition (2012)
  • da Silva, V, Mackey, A, Davis S, Gregory JF. Vitamin B6. In: Ross, AC, Caballero B, Cousins RJ, eds. Modern Nutrition in Health and Disease, 11th edition (2012)
  • Gregory, JF, da Silva, V., Lamers, Y. Kinetics of Folate and One-Carbon Metabolism. In: Bailey LB, ed. Folate in health and disease. CDC Press, 2nd edition 2009.
  • Burns, A, da Silva, V, Martin, A et al. Workshop Summary and Student Voice Report. In: Bennett AB, ed. 2010. National Agricultural Biotechnology Council Report 22: Promoting Health by Linking Agriculture, Food, and Nutrition