Sudeep S. Gill, MD, FRCP(C), Research Fellow, Division of Geriatric Medicine, University of Toronto and Kunin-Lunenfeld Applied Research Unit, Baycrest Centre for Geriatric Care, Toronto, ON.
Shabbir M.H. Alibhai, MD, MSc, FRCP(C), Staff Physician, Department of Medicine, University Health Network, Toronto, ON.
Folate deficiency is relatively common in older adults. There is now growing interest in the roles played by folate and B vitamins in the metabolism of homocysteine. Recent studies have suggested a link between elevated levels of homocysteine and the risk of Alzheimer disease. In this article, we will focus on the physiology and pathophysiology related to folate and homocysteine metabolism. We have also included a discussion of the laboratory evaluation of these compounds. Finally, we review the evidence supporting the relationships between folate deficiency, hyperhomocysteinemia and the development of dementia.
Key words: folic acid, vitamin B12, deficiency diseases, homocysteine, dementia.