1. The statement that folate supraphysiological levels in uremic patients do not cause harm should not go unchallenged
- Author
-
Daniela Bergamo, Giuseppe Aimo, Luisa Sandri, Caterina Canavese, Antonio Marciello, and Giulio Mengozzi
- Subjects
medicine.medical_specialty ,Hyperhomocysteinemia ,education.field_of_study ,Kidney ,business.industry ,Population ,Physiology ,medicine.disease ,Uremia ,Serum folate ,Endocrinology ,medicine.anatomical_structure ,Folic acid ,Nephrology ,Internal medicine ,medicine ,Vitamin B12 ,business ,education ,Adverse effect - Abstract
To the Editor: The excellent paper by De Vriese et al in a recent issue of Kidney International on folate for cardiovascular disease in uremia largely underestimates the risk of folate overdose1. The suggestion that "high doses of folic acid are well tolerated and safe" takes root from four studies with 4 to 8 weeks and 12 to 17 months of follow-up. From one 10-year-old reference is the message that "routine measurement of vitamin B12 concentrations and inclusion of vitamin B12 in the supplements should completely eliminate ... the risk of masking vitamin B12 deficiency." Because close surveillance is suggested to look for adverse effects produced from folate fortification of food in the general population, which increases serum folate from 10.8 to 19.0 ng/mL2, how can we forecast that in uremic people values as high as 200 to 400 ng/mL are safe over a long time? Treatment for hyperhomocysteinemia in uremic patients results in normal vitamin B12 coupled with very high folate concentrations (Fig. 1). Could such an unbalance derange the biochemical basis of folate/vitamin B12 interrelationship producing a "relative" vitamin B12 deficiency?
- Published
- 2003