Ralph Green, M.D., Ph.D., F.R.C. PATH

Ralph Green, M.D., Ph.D., F.R.C. PATH



Pathology and Laboratory Medicine

Pathology - Clinical

Pathology - Hematopathology


  • Professor
To see if Ralph Green is accepting new patients, or for assistance finding a UC Davis doctor, please call 800-2-UCDAVIS (800-282-3284).

Pathology Building

4400 V St.
Sacramento, CA 95817
Driving Directions

Primary Phone:

Additional Phone Numbers

Phone: 916-734-8078
Phone: 916-734-2370
Fax: 916-734-0299
Clinic Fax: 916-734-2560
Physician Referrals: 800-4-UCDAVIS (800-482-3284)

Philosophy of Care

Dr. Green is consulted by patients and physicians on problems relating to vitamin B12 deficiency including pernicious anemia. 

Clinical Interests

Dr. Green is a recognized expert in the diagnosis of Hematological Disorders, with special emphasis on anemias.


Dr. Green is a recognized expert in the diagnosis and treatment of Nutritional deficiency diseases and disorders.


Dr. Green is the Director of the UC Davis Diagnostics, an outreach reference laboratory that performs clinical laboratory tests.



Research/Academic Interests

Dr. Ralph Green has dedicated a major portion of his professional effort to the practice of hematology.  He has served on NIH study sections and as a consultant to the World Health Organization, the Food and Drug Administration and the National Academy of Sciences, Institute of Medicine.  

He has authored or co-authored over 250 publications.  Dr Green serves on the editorial boards of several hematology journals.  

He has been a consultant for several biotechnology and biopharmaceutical companies.  He has recently served as an expert consultant for the NIH Biomarkers of Nutrition for Development group and the NHLBI Working Group on the Microbiome.


Clinical Pathology


M.D., University of Witwatersrand, Johannesburg, South Africa 1964

Ph.D., Hematology/Biochemistry, University of Witwatersrand, Johannesburg, South Africa 1976


Pathology, University of Witwatersrand, Johannesburg, South Africa 1970-1972


Biochemistry, St. Bartholomew’s Hospital & Medical College, London, England 1967-1969

Board Certifications

American Board of Pathology, 1995

Royal College of Pathologists (UK), 2002

Professional Memberships

American Association for Advancement in Science

American Society for Clinical Nutrition

American Society of Clinical Pathology

American Society of Hematology

College of American Pathologists

International Society for Experimental Hematology

International Society for Laboratory Hematology

Western Association of Physicians

Honors and Awards

Berend Houwen Award and lectureship of the International Society of Laboratory Hematology, 2017

Dean’s Award for Excellence in Clinical Care, 2014

Special Award from APC Program Directors for Extraordinary Service to Pathology Resident Education, 2010

American Registry of Pathologists AFIP/Calendar Binford Lecturer Washington, DC, 2006

Royal College of Pathologists, 2002

Opening of Singapore Postgraduate Medical Institute (Keynote Speaker), 1995

Select Recent Publications

Christine CW, Auinger P, Joslin A, Yelpaala Y, Green R; Parkinson Study Group-DATATOP Investigators. Vitamin B12 and homocysteine levels predict different outcomes in early Parkinson's disease. Mov Disord. 2018 Mar 6.

Green R. Vitamin B(12) deficiency from the perspective of a practicing hematologist. Blood. 2017 May 11;129(19):2603-2611.

Green R, Allen LH, Bjørke-Monsen AL, Brito A, Guéant JL, Miller JW, Molloy AM, Nexo E, Stabler S, Toh BH, Ueland PM, Yajnik C. Vitamin B(12) deficiency. Nat Rev Dis Primers. 2017 Jun 29;3:17040.

Paniz C, Bertinato JF, Lucena MR, De Carli E, Amorim PMDS, Gomes GW, Palchetti CZ, Figueiredo MS, Pfeiffer CM, Fazili Z, Green R, Guerra-Shinohara EM. A Daily Dose of 5 mg Folic Acid for 90 Days Is Associated with Increased Serum Unmetabolized Folic Acid and Reduced Natural Killer Cell Cytotoxicity in Healthy Brazilian Adults. J Nutr. 2017 Sep;147(9):1677-1685.

Brito A, Grapov D, Fahrmann J, Harvey D, Green R, Miller JW, Fedosov SN, Shahab-Ferdows S, Hampel D, Pedersen TL, Fiehn O, Newman JW, Uauy R, Allen LH. The Human Serum Metabolome of Vitamin B-12 Deficiency and Repletion, and Associations with Neurological Function in Elderly Adults. J Nutr. 2017 Aug 9. pii: jn248278.

Engle-Stone R, Williams TN, Nankap M, Ndjebayi A, Gimou MM, Oyono Y, Tarini A, Brown KH, Green R. Prevalence of Inherited Hemoglobin Disorders and Relationships with Anemia and Micronutrient Status among Children in Yaoundé and Douala, Cameroon. Nutrients. 2017 Jul 3;9(7). pii: E693.

Green R. Peripheral neuropathy risk and a transcobalamin polymorphism: connecting the dots between excessive folate intake and disease susceptibility.  Am J Clin Nutr. 2016 Nov 16;104(6):1495-6.

Brito A, Verdugo R, Hertrampf E, Miller JW, Green R, Fedosov SN, Shahab-Ferdows S, Sanchez H, Albala C, Castillo JL, Matamala JM, Uauy R, Allen LH. Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated peripheral nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of vitamin B-12 status. Am J Clin Nutr. 2016 Jan;103(1):250-7.

Green R, Dwyre DM. Evaluation of Macrocytic Anemias. Semin Hematol. 2015 Oct;52(4):279-86. Epub 2015 Jun 30. Review. 

Nathanielsz PW, Yan J, Green R, Nijland M, Miller JW, Wu G, McDonald TJ, Caudill MA. Maternal obesity disrupts the methionine cycle in baboon pregnancy. Physiol Rep. 2015 Nov;3(11).